DEV: s/\$redis/Discourse\.redis (#8431)

This commit also adds a rubocop rule to prevent global variables.

.rubocop.yml

@@ -132,8 +132,17 @@ Style/Semicolon:
 Style/RedundantReturn:
   Enabled: true
 
-DiscourseCops/NoChdir:	
-  Enabled: true	
-  Exclude:	
-    - 'spec/**/*' # Specs are run sequentially, so chdir can be used	
+DiscourseCops/NoChdir:
+  Enabled: true
+  Exclude:
+    - 'spec/**/*' # Specs are run sequentially, so chdir can be used
+    - 'plugins/*/spec/**/*'
+
+Style/GlobalVars:
+  Enabled: true
+  Severity: warning
+  Exclude:
+    - 'lib/tasks/**/*'
+    - 'script/**/*'
+    - 'spec/**/*.rb'
     - 'plugins/*/spec/**/*'

app/controllers/application_controller.rb

@@ -768,14 +768,14 @@ class ApplicationController < ActionController::Base
 
     if !SiteSetting.login_required? || (current_user rescue false)
       key = "page_not_found_topics"
-      if @topics_partial = $redis.get(key)
+      if @topics_partial = Discourse.redis.get(key)
         @topics_partial = @topics_partial.html_safe
       else
         category_topic_ids = Category.pluck(:topic_id).compact
         @top_viewed = TopicQuery.new(nil, except_topic_ids: category_topic_ids).list_top_for("monthly").topics.first(10)
         @recent = Topic.includes(:category).where.not(id: category_topic_ids).recent(10)
         @topics_partial = render_to_string partial: '/exceptions/not_found_topics', formats: [:html]
-        $redis.setex(key, 10.minutes, @topics_partial)
+        Discourse.redis.setex(key, 10.minutes, @topics_partial)
       end
     end
 

app/controllers/forums_controller.rb

@@ -9,7 +9,7 @@ class ForumsController < ActionController::Base
   after_action  :add_readonly_header
 
   def status
-    if $shutdown
+    if $shutdown # rubocop:disable Style/GlobalVars
       render plain: "shutting down", status: 500
     else
       render plain: "ok"

app/controllers/session_controller.rb

@@ -409,15 +409,15 @@ class SessionController < ApplicationController
   end
 
   def one_time_password
-    @otp_username = otp_username = $redis.get "otp_#{params[:token]}"
+    @otp_username = otp_username = Discourse.redis.get "otp_#{params[:token]}"
 
     if otp_username && user = User.find_by_username(otp_username)
       if current_user&.username == otp_username
-        $redis.del "otp_#{params[:token]}"
+        Discourse.redis.del "otp_#{params[:token]}"
         return redirect_to path("/")
       elsif request.post?
         log_on_user(user)
-        $redis.del "otp_#{params[:token]}"
+        Discourse.redis.del "otp_#{params[:token]}"
         return redirect_to path("/")
       else
         # Display the form

app/controllers/user_api_keys_controller.rb

@@ -205,7 +205,7 @@ class UserApiKeysController < ApplicationController
     raise Discourse::InvalidAccess unless UserApiKey.allowed_scopes.superset?(Set.new(["one_time_password"]))
 
     otp = SecureRandom.hex
-    $redis.setex "otp_#{otp}", 10.minutes, username
+    Discourse.redis.setex "otp_#{otp}", 10.minutes, username
 
     Base64.encode64(public_key.public_encrypt(otp))
   end

app/controllers/users/associate_accounts_controller.rb

@@ -21,7 +21,7 @@ class Users::AssociateAccountsController < ApplicationController
   # Presents a confirmation screen to the user. Accessed via GET, with no CSRF checks
   def connect
     auth = get_auth_hash
-    $redis.del "#{REDIS_PREFIX}_#{current_user&.id}_#{params[:token]}"
+    Discourse.redis.del "#{REDIS_PREFIX}_#{current_user&.id}_#{params[:token]}"
 
     provider_name = auth.provider
     authenticator = Discourse.enabled_authenticators.find { |a| a.name == provider_name }
@@ -37,7 +37,7 @@ class Users::AssociateAccountsController < ApplicationController
 
   def get_auth_hash
     token = params[:token]
-    json = $redis.get "#{REDIS_PREFIX}_#{current_user&.id}_#{token}"
+    json = Discourse.redis.get "#{REDIS_PREFIX}_#{current_user&.id}_#{token}"
     raise Discourse::NotFound if json.nil?
 
     OmniAuth::AuthHash.new(JSON.parse(json))

app/controllers/users/omniauth_callbacks_controller.rb

@@ -31,7 +31,7 @@ class Users::OmniauthCallbacksController < ApplicationController
     if session.delete(:auth_reconnect) && authenticator.can_connect_existing_user? && current_user
       # Save to redis, with a secret token, then redirect to confirmation screen
       token = SecureRandom.hex
-      $redis.setex "#{Users::AssociateAccountsController::REDIS_PREFIX}_#{current_user.id}_#{token}", 10.minutes, auth.to_json
+      Discourse.redis.setex "#{Users::AssociateAccountsController::REDIS_PREFIX}_#{current_user.id}_#{token}", 10.minutes, auth.to_json
       return redirect_to Discourse.base_uri("/associate/#{token}")
     else
       @auth_result = authenticator.after_authenticate(auth)

app/controllers/webhooks_controller.rb

@@ -119,8 +119,8 @@ class WebhooksController < ActionController::Base
 
     # prevent replay attacks
     key = "mailgun_token_#{token}"
-    return false unless $redis.setnx(key, 1)
-    $redis.expire(key, 10.minutes)
+    return false unless Discourse.redis.setnx(key, 1)
+    Discourse.redis.expire(key, 10.minutes)
 
     # ensure timestamp isn't too far from current time
     return false if (Time.at(timestamp.to_i) - Time.now).abs > 12.hours.to_i

app/helpers/application_helper.rb

@@ -41,7 +41,7 @@ module ApplicationHelper
       return request.env[sk] if request.env[sk]
 
       request.env[sk] = key = (session[sk] ||= SecureRandom.hex)
-      $redis.setex "#{sk}_#{key}", 7.days, current_user.id.to_s
+      Discourse.redis.setex "#{sk}_#{key}", 7.days, current_user.id.to_s
       key
     end
   end

app/jobs/onceoff/clean_up_sidekiq_statistic.rb

@@ -3,7 +3,7 @@
 module Jobs
   class CleanUpSidekiqStatistic < ::Jobs::Onceoff
     def execute_onceoff(args)
-      $redis.without_namespace.del('sidekiq:sidekiq:statistic')
+      Discourse.redis.without_namespace.del('sidekiq:sidekiq:statistic')
     end
   end
 end

app/jobs/onceoff/onceoff.rb

@@ -16,7 +16,7 @@ class Jobs::Onceoff < ::Jobs::Base
   # Pass `force: true` to force it happen again
   def execute(args)
     job_name = self.class.name_for(self.class)
-    has_lock = $redis.setnx(running_key_name, Time.now.to_i)
+    has_lock = Discourse.redis.setnx(running_key_name, Time.now.to_i)
 
     # If we can't get a lock, just noop
     if args[:force] || has_lock
@@ -25,7 +25,7 @@ class Jobs::Onceoff < ::Jobs::Base
         execute_onceoff(args)
         OnceoffLog.create!(job_name: job_name)
       ensure
-        $redis.del(running_key_name) if has_lock
+        Discourse.redis.del(running_key_name) if has_lock
       end
     end
 

app/jobs/regular/run_heartbeat.rb

@@ -10,11 +10,11 @@ module Jobs
     end
 
     def execute(args)
-      $redis.set(self.class.heartbeat_key, Time.new.to_i.to_s)
+      Discourse.redis.set(self.class.heartbeat_key, Time.new.to_i.to_s)
     end
 
     def self.last_heartbeat
-      $redis.get(heartbeat_key).to_i
+      Discourse.redis.get(heartbeat_key).to_i
     end
   end
 end

app/jobs/scheduled/clean_up_uploads.rb

@@ -96,16 +96,16 @@ module Jobs
     end
 
     def last_cleanup=(v)
-      $redis.setex(last_cleanup_key, 7.days.to_i, v.to_s)
+      Discourse.redis.setex(last_cleanup_key, 7.days.to_i, v.to_s)
     end
 
     def last_cleanup
-      v = $redis.get(last_cleanup_key)
+      v = Discourse.redis.get(last_cleanup_key)
       v ? v.to_i : v
     end
 
     def reset_last_cleanup!
-      $redis.del(last_cleanup_key)
+      Discourse.redis.del(last_cleanup_key)
     end
 
     protected

app/jobs/scheduled/pending_queued_posts_reminder.rb

@@ -33,11 +33,11 @@ module Jobs
     end
 
     def last_notified_id
-      (i = $redis.get(self.class.last_notified_key)) && i.to_i
+      (i = Discourse.redis.get(self.class.last_notified_key)) && i.to_i
     end
 
     def last_notified_id=(arg)
-      $redis.set(self.class.last_notified_key, arg)
+      Discourse.redis.set(self.class.last_notified_key, arg)
     end
 
     def self.last_notified_key

app/jobs/scheduled/pending_reviewables_reminder.rb

@@ -37,11 +37,11 @@ module Jobs
     end
 
     def self.last_notified_id
-      $redis.get(last_notified_key).to_i
+      Discourse.redis.get(last_notified_key).to_i
     end
 
     def self.last_notified_id=(arg)
-      $redis.set(last_notified_key, arg)
+      Discourse.redis.set(last_notified_key, arg)
     end
 
     def self.last_notified_key
@@ -49,7 +49,7 @@ module Jobs
     end
 
     def self.clear_key
-      $redis.del(last_notified_key)
+      Discourse.redis.del(last_notified_key)
     end
 
     def active_moderator_usernames

app/jobs/scheduled/pending_users_reminder.rb

@@ -50,11 +50,11 @@ module Jobs
     end
 
     def previous_newest_username
-      $redis.get previous_newest_username_cache_key
+      Discourse.redis.get previous_newest_username_cache_key
     end
 
     def previous_newest_username=(username)
-      $redis.setex previous_newest_username_cache_key, 7.days, username
+      Discourse.redis.setex previous_newest_username_cache_key, 7.days, username
     end
 
     def previous_newest_username_cache_key

app/jobs/scheduled/poll_mailbox.rb

@@ -43,15 +43,15 @@ module Jobs
         end
       end
     rescue Net::OpenTimeout => e
-      count = $redis.incr(POLL_MAILBOX_TIMEOUT_ERROR_KEY).to_i
+      count = Discourse.redis.incr(POLL_MAILBOX_TIMEOUT_ERROR_KEY).to_i
 
-      $redis.expire(
+      Discourse.redis.expire(
         POLL_MAILBOX_TIMEOUT_ERROR_KEY,
         SiteSetting.pop3_polling_period_mins.minutes * 3
       ) if count == 1
 
       if count > 3
-        $redis.del(POLL_MAILBOX_TIMEOUT_ERROR_KEY)
+        Discourse.redis.del(POLL_MAILBOX_TIMEOUT_ERROR_KEY)
         mark_as_errored!
         add_admin_dashboard_problem_message('dashboard.poll_pop3_timeout')
         Discourse.handle_job_exception(e, error_context(@args, "Connecting to '#{SiteSetting.pop3_polling_host}' for polling emails."))
@@ -65,13 +65,13 @@ module Jobs
     POLL_MAILBOX_ERRORS_KEY ||= "poll_mailbox_errors".freeze
 
     def self.errors_in_past_24_hours
-      $redis.zremrangebyscore(POLL_MAILBOX_ERRORS_KEY, 0, 24.hours.ago.to_i)
-      $redis.zcard(POLL_MAILBOX_ERRORS_KEY).to_i
+      Discourse.redis.zremrangebyscore(POLL_MAILBOX_ERRORS_KEY, 0, 24.hours.ago.to_i)
+      Discourse.redis.zcard(POLL_MAILBOX_ERRORS_KEY).to_i
     end
 
     def mark_as_errored!
       now = Time.now.to_i
-      $redis.zadd(POLL_MAILBOX_ERRORS_KEY, now, now.to_s)
+      Discourse.redis.zadd(POLL_MAILBOX_ERRORS_KEY, now, now.to_s)
     end
 
     def add_admin_dashboard_problem_message(i18n_key)

app/mailers/user_notifications.rb

@@ -697,9 +697,9 @@ class UserNotifications < ActionMailer::Base
   def summary_new_users_count(min_date)
     min_date_str = min_date.is_a?(String) ? min_date : min_date.strftime('%Y-%m-%d')
     key = self.class.summary_new_users_count_key(min_date_str)
-    ((count = $redis.get(key)) && count.to_i) || begin
+    ((count = Discourse.redis.get(key)) && count.to_i) || begin
       count = User.real.where(active: true, staged: false).not_suspended.where("created_at > ?", min_date_str).count
-      $redis.setex(key, 1.day, count)
+      Discourse.redis.setex(key, 1.day, count)
       count
     end
   end

app/models/admin_dashboard_data.rb

@@ -63,16 +63,16 @@ class AdminDashboardData
   end
 
   def self.set_problems_started
-    existing_time = $redis.get(problems_started_key)
-    $redis.setex(problems_started_key, 14.days.to_i, existing_time || Time.zone.now.to_s)
+    existing_time = Discourse.redis.get(problems_started_key)
+    Discourse.redis.setex(problems_started_key, 14.days.to_i, existing_time || Time.zone.now.to_s)
   end
 
   def self.clear_problems_started
-    $redis.del problems_started_key
+    Discourse.redis.del problems_started_key
   end
 
   def self.problems_started_at
-    s = $redis.get(problems_started_key)
+    s = Discourse.redis.get(problems_started_key)
     s ? Time.zone.parse(s) : nil
   end
 
@@ -109,19 +109,19 @@ class AdminDashboardData
   end
 
   def self.problem_message_check(i18n_key)
-    $redis.get(problem_message_key(i18n_key)) ? I18n.t(i18n_key, base_path: Discourse.base_path) : nil
+    Discourse.redis.get(problem_message_key(i18n_key)) ? I18n.t(i18n_key, base_path: Discourse.base_path) : nil
   end
 
   def self.add_problem_message(i18n_key, expire_seconds = nil)
     if expire_seconds.to_i > 0
-      $redis.setex problem_message_key(i18n_key), expire_seconds.to_i, 1
+      Discourse.redis.setex problem_message_key(i18n_key), expire_seconds.to_i, 1
     else
-      $redis.set problem_message_key(i18n_key), 1
+      Discourse.redis.set problem_message_key(i18n_key), 1
     end
   end
 
   def self.clear_problem_message(i18n_key)
-    $redis.del problem_message_key(i18n_key)
+    Discourse.redis.del problem_message_key(i18n_key)
   end
 
   def self.problem_message_key(i18n_key)

app/models/application_request.rb

@@ -52,7 +52,7 @@ class ApplicationRequest < ActiveRecord::Base
 
     req_types.each do |req_type, _|
       key = redis_key(req_type, date)
-      $redis.del key
+      Discourse.redis.del key
     end
   end
 

app/models/category_featured_topic.rb

@@ -16,7 +16,7 @@ class CategoryFeaturedTopic < ActiveRecord::Base
 
     batch_size ||= DEFAULT_BATCH_SIZE
 
-    next_category_id = batched ? $redis.get(NEXT_CATEGORY_ID_KEY).to_i : 0
+    next_category_id = batched ? Discourse.redis.get(NEXT_CATEGORY_ID_KEY).to_i : 0
 
     categories = Category.select(:id, :topic_id, :num_featured_topics)
       .where('id >= ?', next_category_id)
@@ -27,7 +27,7 @@ class CategoryFeaturedTopic < ActiveRecord::Base
     if batched
       if categories.length == batch_size
         next_id = Category.where('id > ?', categories.last.id).order('id asc').limit(1).pluck(:id)[0]
-        next_id ? $redis.setex(NEXT_CATEGORY_ID_KEY, 1.day, next_id) : clear_batch!
+        next_id ? Discourse.redis.setex(NEXT_CATEGORY_ID_KEY, 1.day, next_id) : clear_batch!
       else
         clear_batch!
       end
@@ -39,7 +39,7 @@ class CategoryFeaturedTopic < ActiveRecord::Base
   end
 
   def self.clear_batch!
-    $redis.del(NEXT_CATEGORY_ID_KEY)
+    Discourse.redis.del(NEXT_CATEGORY_ID_KEY)
   end
 
   def self.feature_topics_for(c, existing = nil)

app/models/concerns/cached_counting.rb

@@ -19,13 +19,13 @@ module CachedCounting
 
   class_methods do
     def perform_increment!(key, opts = nil)
-      val = $redis.incr(key).to_i
+      val = Discourse.redis.incr(key).to_i
 
       # readonly mode it is going to be 0, skip
       return if val == 0
 
       # 3.days, see: https://github.com/rails/rails/issues/21296
-      $redis.expire(key, 259200)
+      Discourse.redis.expire(key, 259200)
 
       autoflush = (opts && opts[:autoflush]) || self.autoflush
       if autoflush > 0 && val >= autoflush
@@ -51,9 +51,9 @@ module CachedCounting
     # this may seem a bit fancy but in so it allows
     # for concurrent calls without double counting
     def get_and_reset(key)
-      namespaced_key = $redis.namespace_key(key)
-      val = $redis.without_namespace.eval(GET_AND_RESET, keys: [namespaced_key]).to_i
-      $redis.expire(key, 259200) # SET removes expiry, so set it again
+      namespaced_key = Discourse.redis.namespace_key(key)
+      val = Discourse.redis.without_namespace.eval(GET_AND_RESET, keys: [namespaced_key]).to_i
+      Discourse.redis.expire(key, 259200) # SET removes expiry, so set it again
       val
     end
 

app/models/concerns/stats_cacheable.rb

@@ -19,7 +19,7 @@ module StatsCacheable
 
     def fetch_cached_stats
       # The scheduled Stats job is responsible for generating and caching this.
-      stats = $redis.get(stats_cache_key)
+      stats = Discourse.redis.get(stats_cache_key)
       stats = refresh_stats if !stats
       JSON.parse(stats).with_indifferent_access
     end
@@ -35,7 +35,7 @@ module StatsCacheable
     def set_cache(stats)
       # Add some extra time to the expiry so that the next job run has plenty of time to
       # finish before previous cached value expires.
-      $redis.setex stats_cache_key, (recalculate_stats_interval + 5).minutes, stats
+      Discourse.redis.setex stats_cache_key, (recalculate_stats_interval + 5).minutes, stats
     end
   end
 end

app/models/global_setting.rb

@@ -26,9 +26,9 @@ class GlobalSetting
 
     if @safe_secret_key_base && @token_in_redis && (@token_last_validated + REDIS_VALIDATE_SECONDS) < Time.now
       @token_last_validated = Time.now
-      token = $redis.without_namespace.get(REDIS_SECRET_KEY)
+      token = Discourse.redis.without_namespace.get(REDIS_SECRET_KEY)
       if token.nil?
-        $redis.without_namespace.set(REDIS_SECRET_KEY, @safe_secret_key_base)
+        Discourse.redis.without_namespace.set(REDIS_SECRET_KEY, @safe_secret_key_base)
       end
     end
 
@@ -39,10 +39,10 @@ class GlobalSetting
         @token_in_redis = true
         @token_last_validated = Time.now
 
-        token = $redis.without_namespace.get(REDIS_SECRET_KEY)
+        token = Discourse.redis.without_namespace.get(REDIS_SECRET_KEY)
         unless token && token =~ VALID_SECRET_KEY
           token = SecureRandom.hex(64)
-          $redis.without_namespace.set(REDIS_SECRET_KEY, token)
+          Discourse.redis.without_namespace.set(REDIS_SECRET_KEY, token)
         end
       end
       if !secret_key_base.blank? && token != secret_key_base

app/models/post.rb

@@ -247,12 +247,12 @@ class Post < ActiveRecord::Base
 
   def store_unique_post_key
     if SiteSetting.unique_posts_mins > 0
-      $redis.setex(unique_post_key, SiteSetting.unique_posts_mins.minutes.to_i, id)
+      Discourse.redis.setex(unique_post_key, SiteSetting.unique_posts_mins.minutes.to_i, id)
     end
   end
 
   def matches_recent_post?
-    post_id = $redis.get(unique_post_key)
+    post_id = Discourse.redis.get(unique_post_key)
     post_id != (nil) && post_id.to_i != (id)
   end
 
@@ -696,11 +696,11 @@ class Post < ActiveRecord::Base
   end
 
   def self.estimate_posts_per_day
-    val = $redis.get("estimated_posts_per_day")
+    val = Discourse.redis.get("estimated_posts_per_day")
     return val.to_i if val
 
     posts_per_day = Topic.listable_topics.secured.joins(:posts).merge(Post.created_since(30.days.ago)).count / 30
-    $redis.setex("estimated_posts_per_day", 1.day.to_i, posts_per_day.to_s)
+    Discourse.redis.setex("estimated_posts_per_day", 1.day.to_i, posts_per_day.to_s)
     posts_per_day
 
   end

app/models/search_log.rb

@@ -39,8 +39,8 @@ class SearchLog < ActiveRecord::Base
 
   # for testing
   def self.clear_debounce_cache!
-    $redis.keys("__SEARCH__LOG_*").each do |k|
-      $redis.del(k)
+    Discourse.redis.keys("__SEARCH__LOG_*").each do |k|
+      Discourse.redis.del(k)
     end
   end
 
@@ -56,7 +56,7 @@ class SearchLog < ActiveRecord::Base
 
     result = nil
 
-    if existing = $redis.get(key)
+    if existing = Discourse.redis.get(key)
       id, old_term = existing.split(",", 2)
 
       if term.start_with?(old_term)
@@ -80,7 +80,7 @@ class SearchLog < ActiveRecord::Base
       result = [:created, log.id]
     end
 
-    $redis.setex(key, 5, "#{result[1]},#{term}")
+    Discourse.redis.setex(key, 5, "#{result[1]},#{term}")
 
     result
   end

app/models/site.rb

@@ -102,7 +102,7 @@ class Site
     if guardian.anonymous?
       seq = MessageBus.last_id('/site_json')
 
-      cached_json, cached_seq, cached_version = $redis.mget('site_json', 'site_json_seq', 'site_json_version')
+      cached_json, cached_seq, cached_version = Discourse.redis.mget('site_json', 'site_json_seq', 'site_json_version')
 
       if cached_json && seq == cached_seq.to_i && Discourse.git_version == cached_version
         return cached_json
@@ -114,10 +114,10 @@ class Site
     json = MultiJson.dump(SiteSerializer.new(site, root: false, scope: guardian))
 
     if guardian.anonymous?
-      $redis.multi do
-        $redis.setex 'site_json', 1800, json
-        $redis.set 'site_json_seq', seq
-        $redis.set 'site_json_version', Discourse.git_version
+      Discourse.redis.multi do
+        Discourse.redis.setex 'site_json', 1800, json
+        Discourse.redis.set 'site_json_seq', seq
+        Discourse.redis.set 'site_json_version', Discourse.git_version
       end
     end
 

app/models/topic_link_click.rb

@@ -102,8 +102,8 @@ class TopicLinkClick < ActiveRecord::Base
 
     # Rate limit the click counts to once in 24 hours
     rate_key = "link-clicks:#{link.id}:#{args[:user_id] || args[:ip]}"
-    if $redis.setnx(rate_key, "1")
-      $redis.expire(rate_key, 1.day.to_i)
+    if Discourse.redis.setnx(rate_key, "1")
+      Discourse.redis.expire(rate_key, 1.day.to_i)
       args[:ip] = nil if args[:user_id]
       create!(topic_link_id: link.id, user_id: args[:user_id], ip_address: args[:ip])
     end

app/models/topic_view_item.rb

@@ -18,8 +18,8 @@ class TopicViewItem < ActiveRecord::Base
       redis_key << ":ip-#{ip}"
     end
 
-    if skip_redis || $redis.setnx(redis_key, "1")
-      skip_redis || $redis.expire(redis_key, SiteSetting.topic_view_duration_hours.hours)
+    if skip_redis || Discourse.redis.setnx(redis_key, "1")
+      skip_redis || Discourse.redis.expire(redis_key, SiteSetting.topic_view_duration_hours.hours)
 
       TopicViewItem.transaction do
         # this is called real frequently, working hard to avoid exceptions

app/models/trust_level3_requirements.rb

@@ -243,8 +243,8 @@ class TrustLevel3Requirements
   end
 
   def self.clear_cache
-    $redis.del NUM_TOPICS_KEY
-    $redis.del NUM_POSTS_KEY
+    Discourse.redis.del NUM_TOPICS_KEY
+    Discourse.redis.del NUM_POSTS_KEY
   end
 
   CACHE_DURATION = 1.day.seconds - 60
@@ -252,17 +252,17 @@ class TrustLevel3Requirements
   NUM_POSTS_KEY  = "tl3_num_posts"
 
   def self.num_topics_in_time_period
-    $redis.get(NUM_TOPICS_KEY) || begin
+    Discourse.redis.get(NUM_TOPICS_KEY) || begin
       count = Topic.listable_topics.visible.created_since(SiteSetting.tl3_time_period.days.ago).count
-      $redis.setex NUM_TOPICS_KEY, CACHE_DURATION, count
+      Discourse.redis.setex NUM_TOPICS_KEY, CACHE_DURATION, count
       count
     end
   end
 
   def self.num_posts_in_time_period
-    $redis.get(NUM_POSTS_KEY) || begin
+    Discourse.redis.get(NUM_POSTS_KEY) || begin
       count = Post.public_posts.visible.created_since(SiteSetting.tl3_time_period.days.ago).count
-      $redis.setex NUM_POSTS_KEY, CACHE_DURATION, count
+      Discourse.redis.setex NUM_POSTS_KEY, CACHE_DURATION, count
       count
     end
   end

app/models/user.rb

@@ -711,9 +711,9 @@ class User < ActiveRecord::Base
     now_date = now.to_date
     # Only update last seen once every minute
     redis_key = "user:#{id}:#{now_date}"
-    return unless $redis.setnx(redis_key, "1")
+    return unless Discourse.redis.setnx(redis_key, "1")
 
-    $redis.expire(redis_key, SiteSetting.active_user_rate_limit_secs)
+    Discourse.redis.expire(redis_key, SiteSetting.active_user_rate_limit_secs)
     update_previous_visit(now)
     # using update_column to avoid the AR transaction
     update_column(:last_seen_at, now)

app/models/user_option.rb

@@ -94,8 +94,8 @@ class UserOption < ActiveRecord::Base
     delay = SiteSetting.active_user_rate_limit_secs
 
     # only update last_redirected_to_top_at once every minute
-    return unless $redis.setnx(key, "1")
-    $redis.expire(key, delay)
+    return unless Discourse.redis.setnx(key, "1")
+    Discourse.redis.expire(key, delay)
 
     # delay the update
     Jobs.enqueue_in(delay / 2, :update_top_redirection, user_id: self.user_id, redirected_at: Time.zone.now)

app/models/user_profile_view.rb

@@ -16,8 +16,8 @@ class UserProfileView < ActiveRecord::Base
       redis_key << ":ip-#{ip}"
     end
 
-    if skip_redis || $redis.setnx(redis_key, '1')
-      skip_redis || $redis.expire(redis_key, SiteSetting.user_profile_view_duration_hours.hours)
+    if skip_redis || Discourse.redis.setnx(redis_key, '1')
+      skip_redis || Discourse.redis.expire(redis_key, SiteSetting.user_profile_view_duration_hours.hours)
 
       self.transaction do
         sql = "INSERT INTO user_profile_views (user_profile_id, ip_address, viewed_at, user_id)

app/models/user_stat.rb

@@ -163,11 +163,11 @@ class UserStat < ActiveRecord::Base
   end
 
   def self.last_seen_cached(id)
-    $redis.get(last_seen_key(id))
+    Discourse.redis.get(last_seen_key(id))
   end
 
   def self.cache_last_seen(id, val)
-    $redis.setex(last_seen_key(id), MAX_TIME_READ_DIFF, val)
+    Discourse.redis.setex(last_seen_key(id), MAX_TIME_READ_DIFF, val)
   end
 
   protected

app/models/web_crawler_request.rb

@@ -16,8 +16,8 @@ class WebCrawlerRequest < ActiveRecord::Base
 
   def self.increment!(user_agent, opts = nil)
     ua_list_key = user_agent_list_key
-    $redis.sadd(ua_list_key, user_agent)
-    $redis.expire(ua_list_key, 259200) # 3.days
+    Discourse.redis.sadd(ua_list_key, user_agent)
+    Discourse.redis.expire(ua_list_key, 259200) # 3.days
 
     perform_increment!(redis_key(user_agent), opts)
   end
@@ -34,7 +34,7 @@ class WebCrawlerRequest < ActiveRecord::Base
     date = date.to_date
     ua_list_key = user_agent_list_key(date)
 
-    while user_agent = $redis.spop(ua_list_key)
+    while user_agent = Discourse.redis.spop(ua_list_key)
       val = get_and_reset(redis_key(user_agent, date))
 
       next if val == 0
@@ -55,11 +55,11 @@ class WebCrawlerRequest < ActiveRecord::Base
 
     ua_list_key = user_agent_list_key(date)
 
-    while user_agent = $redis.spop(ua_list_key)
-      $redis.del redis_key(user_agent, date)
+    while user_agent = Discourse.redis.spop(ua_list_key)
+      Discourse.redis.del redis_key(user_agent, date)
     end
 
-    $redis.del(ua_list_key)
+    Discourse.redis.del(ua_list_key)
   end
 
   protected

app/services/badge_granter.rb

@@ -122,17 +122,17 @@ class BadgeGranter
       }
     end
 
-    $redis.lpush queue_key, payload.to_json if payload
+    Discourse.redis.lpush queue_key, payload.to_json if payload
   end
 
   def self.clear_queue!
-    $redis.del queue_key
+    Discourse.redis.del queue_key
   end
 
   def self.process_queue!
     limit = 1000
     items = []
-    while limit > 0 && item = $redis.lpop(queue_key)
+    while limit > 0 && item = Discourse.redis.lpop(queue_key)
       items << JSON.parse(item)
       limit -= 1
     end

app/services/group_message.rb

@@ -54,12 +54,12 @@ class GroupMessage
 
   def sent_recently?
     return false if @opts[:limit_once_per] == false
-    $redis.get(sent_recently_key).present?
+    Discourse.redis.get(sent_recently_key).present?
   end
 
   # default is to send no more than once every 24 hours (24 * 60 * 60 = 86,400 seconds)
   def remember_message_sent
-    $redis.setex(sent_recently_key, @opts[:limit_once_per].try(:to_i) || 86_400, 1) unless @opts[:limit_once_per] == false
+    Discourse.redis.setex(sent_recently_key, @opts[:limit_once_per].try(:to_i) || 86_400, 1) unless @opts[:limit_once_per] == false
   end
 
   def sent_recently_key

app/services/random_topic_selector.rb

@@ -40,9 +40,9 @@ class RandomTopicSelector
     key = cache_key(category)
 
     if results.present?
-      $redis.multi do
-        $redis.rpush(key, results)
-        $redis.expire(key, 2.days)
+      Discourse.redis.multi do
+        Discourse.redis.rpush(key, results)
+        Discourse.redis.expire(key, 2.days)
       end
     end
 
@@ -56,13 +56,13 @@ class RandomTopicSelector
 
     return results if count < 1
 
-    results = $redis.multi do
-      $redis.lrange(key, 0, count - 1)
-      $redis.ltrim(key, count, -1)
+    results = Discourse.redis.multi do
+      Discourse.redis.lrange(key, 0, count - 1)
+      Discourse.redis.ltrim(key, count, -1)
     end
 
     if !results.is_a?(Array) # Redis is in readonly mode
-      results = $redis.lrange(key, 0, count - 1)
+      results = Discourse.redis.lrange(key, 0, count - 1)
     else
       results = results[0]
     end
@@ -80,7 +80,7 @@ class RandomTopicSelector
       results = results[0...count]
     end
 
-    if !backfilled && $redis.llen(key) < BACKFILL_LOW_WATER_MARK
+    if !backfilled && Discourse.redis.llen(key) < BACKFILL_LOW_WATER_MARK
       Scheduler::Defer.later("backfill") do
         backfill(category)
       end
@@ -94,7 +94,7 @@ class RandomTopicSelector
   end
 
   def self.clear_cache!
-    $redis.delete_prefixed(cache_key)
+    Discourse.redis.delete_prefixed(cache_key)
   end
 
 end

app/services/topic_timestamp_changer.rb

@@ -35,7 +35,7 @@ class TopicTimestampChanger
     end
 
     # Burst the cache for stats
-    [AdminDashboardData, About].each { |klass| $redis.del klass.stats_cache_key }
+    [AdminDashboardData, About].each { |klass| Discourse.redis.del klass.stats_cache_key }
   end
 
   private

config/application.rb

@@ -243,7 +243,7 @@ module Discourse
     require 'logster/redis_store'
     # Use redis for our cache
     config.cache_store = DiscourseRedis.new_redis_store
-    $redis = DiscourseRedis.new
+    $redis = DiscourseRedis.new # rubocop:disable Style/GlobalVars
     Logster.store = Logster::RedisStore.new(DiscourseRedis.new)
 
     # we configure rack cache on demand in an initializer

config/initializers/001-redis.rb

@@ -2,5 +2,5 @@
 
 if Rails.env.development? && ENV['DISCOURSE_FLUSH_REDIS']
   puts "Flushing redis (development mode)"
-  $redis.flushall
+  Discourse.redis.flushall
 end

config/initializers/100-sidekiq.rb

@@ -24,7 +24,7 @@ end
 
 MiniScheduler.configure do |config|
 
-  config.redis = $redis
+  config.redis = Discourse.redis
 
   config.job_exception_handler do |ex, context|
     Discourse.handle_job_exception(ex, context)

config/initializers/100-watch_for_restart.rb

@@ -29,7 +29,7 @@ Thread.new do
 
         if old_time != time
           Rails.logger.info "attempting to reload #{$$} #{$PROGRAM_NAME} in #{wait_seconds} seconds"
-          $shutdown = true
+          $shutdown = true # rubocop:disable Style/GlobalVars
           sleep wait_seconds
           Rails.logger.info "restarting #{$$}"
           Process.kill("USR2", $$)

config/unicorn.conf.rb

@@ -155,7 +155,7 @@ before_fork do |server, worker|
               sleep 10
               force_kill_rogue_sidekiq
             end
-            $redis._client.disconnect
+            Discourse.redis._client.disconnect
           end
         end
 
@@ -170,7 +170,7 @@ before_fork do |server, worker|
 
   end
 
-  $redis._client.disconnect
+  Discourse.redis._client.disconnect
 
   # Throttle the master from forking too quickly by sleeping.  Due
   # to the implementation of standard Unix signal handlers, this

db/migrate/20150213174159_create_digest_unsubscribe_keys.rb

@@ -18,18 +18,18 @@ class CreateDigestUnsubscribeKeys < ActiveRecord::Migration[4.2]
   def migrate_redis_keys
     return if Rails.env.test?
 
-    temp_keys = $redis.keys('temporary_key:*')
+    temp_keys = Discourse.redis.keys('temporary_key:*')
     if temp_keys.present?
       temp_keys.map! do |key|
-        user_id = $redis.get(key).to_i
-        ttl = $redis.ttl(key).to_i
+        user_id = Discourse.redis.get(key).to_i
+        ttl = Discourse.redis.ttl(key).to_i
 
         if ttl > 0
           ttl = "'#{ttl.seconds.ago.strftime('%Y-%m-%d %H:%M:%S')}'"
         else
           ttl = "CURRENT_TIMESTAMP"
         end
-        $redis.del(key)
+        Discourse.redis.del(key)
         key.gsub!('temporary_key:', '')
         user_id ? "('#{key}', #{user_id}, #{ttl}, #{ttl})" : nil
       end

db/migrate/20160303183607_clear_common_passwords_cache.rb

@@ -4,6 +4,6 @@ require "common_passwords/common_passwords"
 
 class ClearCommonPasswordsCache < ActiveRecord::Migration[4.2]
   def change
-    $redis.without_namespace.del CommonPasswords::LIST_KEY
+    Discourse.redis.without_namespace.del CommonPasswords::LIST_KEY
   end
 end

lib/admin_confirmation.rb

@@ -15,13 +15,13 @@ class AdminConfirmation
     guardian.ensure_can_grant_admin!(@target_user)
 
     @token = SecureRandom.hex
-    $redis.setex("admin-confirmation:#{@target_user.id}", 3.hours.to_i, @token)
+    Discourse.redis.setex("admin-confirmation:#{@target_user.id}", 3.hours.to_i, @token)
 
     payload = {
       target_user_id: @target_user.id,
       performed_by: @performed_by.id
     }
-    $redis.setex("admin-confirmation-token:#{@token}", 3.hours.to_i, payload.to_json)
+    Discourse.redis.setex("admin-confirmation-token:#{@token}", 3.hours.to_i, payload.to_json)
 
     Jobs.enqueue(
       :admin_confirmation_email,
@@ -38,16 +38,16 @@ class AdminConfirmation
 
     @target_user.grant_admin!
     StaffActionLogger.new(@performed_by).log_grant_admin(@target_user)
-    $redis.del "admin-confirmation:#{@target_user.id}"
-    $redis.del "admin-confirmation-token:#{@token}"
+    Discourse.redis.del "admin-confirmation:#{@target_user.id}"
+    Discourse.redis.del "admin-confirmation-token:#{@token}"
   end
 
   def self.exists_for?(user_id)
-    $redis.exists "admin-confirmation:#{user_id}"
+    Discourse.redis.exists "admin-confirmation:#{user_id}"
   end
 
   def self.find_by_code(token)
-    json = $redis.get("admin-confirmation-token:#{token}")
+    json = Discourse.redis.get("admin-confirmation-token:#{token}")
     return nil unless json
 
     parsed = JSON.parse(json)

lib/auth/default_current_user_provider.rb

@@ -30,7 +30,7 @@ class Auth::DefaultCurrentUserProvider
 
     # bypass if we have the shared session header
     if shared_key = @env['HTTP_X_SHARED_SESSION_KEY']
-      uid = $redis.get("shared_session_key_#{shared_key}")
+      uid = Discourse.redis.get("shared_session_key_#{shared_key}")
       user = nil
       if uid
         user = User.find_by(id: uid.to_i)

lib/auth/open_id_authenticator.rb

@@ -87,7 +87,7 @@ class Auth::OpenIdAuthenticator < Auth::Authenticator
     omniauth.provider :open_id,
          setup: lambda { |env|
            strategy = env["omniauth.strategy"]
-           strategy.options[:store] = OpenID::Store::Redis.new($redis)
+           strategy.options[:store] = OpenID::Store::Redis.new(Discourse.redis)
 
            # Add CSRF protection in addition to OpenID Specification
            def strategy.query_string

lib/backup_restore.rb

@@ -36,21 +36,21 @@ module BackupRestore
   end
 
   def self.mark_as_running!
-    $redis.setex(running_key, 60, "1")
+    Discourse.redis.setex(running_key, 60, "1")
     save_start_logs_message_id
     keep_it_running
   end
 
   def self.is_operation_running?
-    !!$redis.get(running_key)
+    !!Discourse.redis.get(running_key)
   end
 
   def self.mark_as_not_running!
-    $redis.del(running_key)
+    Discourse.redis.del(running_key)
   end
 
   def self.should_shutdown?
-    !!$redis.get(shutdown_signal_key)
+    !!Discourse.redis.get(shutdown_signal_key)
   end
 
   def self.can_rollback?
@@ -128,7 +128,7 @@ module BackupRestore
     Thread.new do
       # this thread will be killed when the fork dies
       while true
-        $redis.expire(running_key, 1.minute)
+        Discourse.redis.expire(running_key, 1.minute)
         sleep 30.seconds
       end
     end
@@ -139,20 +139,20 @@ module BackupRestore
   end
 
   def self.set_shutdown_signal!
-    $redis.set(shutdown_signal_key, "1")
+    Discourse.redis.set(shutdown_signal_key, "1")
   end
 
   def self.clear_shutdown_signal!
-    $redis.del(shutdown_signal_key)
+    Discourse.redis.del(shutdown_signal_key)
   end
 
   def self.save_start_logs_message_id
     id = MessageBus.last_id(LOGS_CHANNEL)
-    $redis.set(start_logs_message_id_key, id)
+    Discourse.redis.set(start_logs_message_id_key, id)
   end
 
   def self.start_logs_message_id
-    $redis.get(start_logs_message_id_key).to_i
+    Discourse.redis.get(start_logs_message_id_key).to_i
   end
 
   def self.start_logs_message_id_key

lib/cache.rb

@@ -5,7 +5,7 @@
 # This is a bottom up implementation of ActiveSupport::Cache::Store
 # this allows us to cleanly implement without using cache entries and version
 # support which we do not use, in tern this makes the cache as fast as simply
-# using `$redis.setex` with a more convenient API
+# using `Discourse.redis.setex` with a more convenient API
 #
 # It only implements a subset of ActiveSupport::Cache::Store as we make no use
 # of large parts of the interface.
@@ -33,7 +33,7 @@ class Cache
   end
 
   def redis
-    $redis
+    Discourse.redis
   end
 
   def reconnect

lib/common_passwords/common_passwords.rb

@@ -9,7 +9,7 @@
 # If the password file is changed, you need to add a migration that deletes the list from redis
 # so it gets re-populated:
 #
-#   $redis.without_namespace.del CommonPasswords::LIST_KEY
+#   Discourse.redis.without_namespace.del CommonPasswords::LIST_KEY
 
 class CommonPasswords
 
@@ -39,7 +39,7 @@ class CommonPasswords
   end
 
   def self.redis
-    $redis.without_namespace
+    Discourse.redis.without_namespace
   end
 
   def self.load_passwords

lib/discourse.rb

@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+# rubocop:disable Style/GlobalVars
 
 require 'cache'
 require 'open3'
@@ -378,9 +379,9 @@ module Discourse
 
   def self.enable_readonly_mode(key = READONLY_MODE_KEY)
     if key == USER_READONLY_MODE_KEY
-      $redis.set(key, 1)
+      Discourse.redis.set(key, 1)
     else
-      $redis.setex(key, READONLY_MODE_KEY_TTL, 1)
+      Discourse.redis.setex(key, READONLY_MODE_KEY_TTL, 1)
       keep_readonly_mode(key) if !Rails.env.test?
     end
 
@@ -406,7 +407,7 @@ module Discourse
             @mutex.synchronize do
               @dbs.each do |db|
                 RailsMultisite::ConnectionManagement.with_connection(db) do
-                  if !$redis.expire(key, READONLY_MODE_KEY_TTL)
+                  if !Discourse.redis.expire(key, READONLY_MODE_KEY_TTL)
                     @dbs.delete(db)
                   end
                 end
@@ -419,18 +420,18 @@ module Discourse
   end
 
   def self.disable_readonly_mode(key = READONLY_MODE_KEY)
-    $redis.del(key)
+    Discourse.redis.del(key)
     MessageBus.publish(readonly_channel, false)
     Site.clear_anon_cache!
     true
   end
 
   def self.readonly_mode?(keys = READONLY_KEYS)
-    recently_readonly? || $redis.mget(*keys).compact.present?
+    recently_readonly? || Discourse.redis.mget(*keys).compact.present?
   end
 
   def self.pg_readonly_mode?
-    $redis.get(PG_READONLY_MODE_KEY).present?
+    Discourse.redis.get(PG_READONLY_MODE_KEY).present?
   end
 
   # Shared between processes
@@ -444,23 +445,23 @@ module Discourse
   end
 
   def self.recently_readonly?
-    postgres_read_only = postgres_last_read_only[$redis.namespace]
-    redis_read_only = redis_last_read_only[$redis.namespace]
+    postgres_read_only = postgres_last_read_only[Discourse.redis.namespace]
+    redis_read_only = redis_last_read_only[Discourse.redis.namespace]
 
     (redis_read_only.present? && redis_read_only > 15.seconds.ago) ||
       (postgres_read_only.present? && postgres_read_only > 15.seconds.ago)
   end
 
   def self.received_postgres_readonly!
-    postgres_last_read_only[$redis.namespace] = Time.zone.now
+    postgres_last_read_only[Discourse.redis.namespace] = Time.zone.now
   end
 
   def self.received_redis_readonly!
-    redis_last_read_only[$redis.namespace] = Time.zone.now
+    redis_last_read_only[Discourse.redis.namespace] = Time.zone.now
   end
 
   def self.clear_readonly!
-    postgres_last_read_only[$redis.namespace] = redis_last_read_only[$redis.namespace] = nil
+    postgres_last_read_only[Discourse.redis.namespace] = redis_last_read_only[Discourse.redis.namespace] = nil
     Site.clear_anon_cache!
     true
   end
@@ -491,7 +492,7 @@ module Discourse
       begin
         git_cmd = 'git rev-parse HEAD'
         self.try_git(git_cmd, Discourse::VERSION::STRING)
-      end
+      end # rubocop:disable Style/GlobalVars
   end
 
   def self.git_branch
@@ -589,7 +590,7 @@ module Discourse
     # note: some of this reconnecting may no longer be needed per https://github.com/redis/redis-rb/pull/414
     MessageBus.after_fork
     SiteSetting.after_fork
-    $redis._client.reconnect
+    Discourse.redis._client.reconnect
     Rails.cache.reconnect
     Discourse.cache.reconnect
     Logster.store.redis.reconnect
@@ -737,10 +738,10 @@ module Discourse
     digest = Digest::MD5.hexdigest(warning)
     redis_key = "deprecate-notice-#{digest}"
 
-    if !$redis.without_namespace.get(redis_key)
+    if !Discourse.redis.without_namespace.get(redis_key)
       Rails.logger.warn(warning)
       begin
-        $redis.without_namespace.setex(redis_key, 3600, "x")
+        Discourse.redis.without_namespace.setex(redis_key, 3600, "x")
       rescue Redis::CommandError => e
         raise unless e.message =~ /READONLY/
       end
@@ -832,4 +833,10 @@ module Discourse
   ensure
     @preloaded_rails = true
   end
+
+  def self.redis
+    $redis
+  end
 end
+
+# rubocop:enable Style/GlobalVars

lib/discourse_hub.rb

@@ -14,7 +14,7 @@ module DiscourseHub
   end
 
   def self.stats_fetched_at=(time_with_zone)
-    $redis.set STATS_FETCHED_AT_KEY, time_with_zone.to_i
+    Discourse.redis.set STATS_FETCHED_AT_KEY, time_with_zone.to_i
   end
 
   def self.get_payload
@@ -102,7 +102,7 @@ module DiscourseHub
   end
 
   def self.stats_fetched_at
-    t = $redis.get(STATS_FETCHED_AT_KEY)
+    t = Discourse.redis.get(STATS_FETCHED_AT_KEY)
     t ? Time.zone.at(t.to_i) : 1.year.ago
   end
 

lib/discourse_redis.rb

@@ -262,7 +262,7 @@ class DiscourseRedis
 
   def delete_prefixed(prefix)
     DiscourseRedis.ignore_readonly do
-      keys("#{prefix}*").each { |k| $redis.del(k) }
+      keys("#{prefix}*").each { |k| Discourse.redis.del(k) }
     end
   end
 

lib/discourse_updates.rb

@@ -58,42 +58,42 @@ module DiscourseUpdates
 
     # last_installed_version is the installed version at the time of the last version check
     def last_installed_version
-      $redis.get last_installed_version_key
+      Discourse.redis.get last_installed_version_key
     end
 
     def latest_version
-      $redis.get latest_version_key
+      Discourse.redis.get latest_version_key
     end
 
     def missing_versions_count
-      $redis.get(missing_versions_count_key).try(:to_i)
+      Discourse.redis.get(missing_versions_count_key).try(:to_i)
     end
 
     def critical_updates_available?
-      ($redis.get(critical_updates_available_key) || false) == 'true'
+      (Discourse.redis.get(critical_updates_available_key) || false) == 'true'
     end
 
     def updated_at
-      t = $redis.get(updated_at_key)
+      t = Discourse.redis.get(updated_at_key)
       t ? Time.zone.parse(t) : nil
     end
 
     def updated_at=(time_with_zone)
-      $redis.set updated_at_key, time_with_zone.as_json
+      Discourse.redis.set updated_at_key, time_with_zone.as_json
     end
 
     ['last_installed_version', 'latest_version', 'missing_versions_count', 'critical_updates_available'].each do |name|
       eval "define_method :#{name}= do |arg|
-        $redis.set #{name}_key, arg
+        Discourse.redis.set #{name}_key, arg
       end"
     end
 
     def missing_versions=(versions)
       # delete previous list from redis
-      prev_keys = $redis.lrange(missing_versions_list_key, 0, 4)
+      prev_keys = Discourse.redis.lrange(missing_versions_list_key, 0, 4)
       if prev_keys
-        $redis.del prev_keys
-        $redis.del(missing_versions_list_key)
+        Discourse.redis.del prev_keys
+        Discourse.redis.del(missing_versions_list_key)
       end
 
       if versions.present?
@@ -101,18 +101,18 @@ module DiscourseUpdates
         version_keys = []
         versions[0, 5].each do |v|
           key = "#{missing_versions_key_prefix}:#{v['version']}"
-          $redis.mapped_hmset key, v
+          Discourse.redis.mapped_hmset key, v
           version_keys << key
         end
-        $redis.rpush missing_versions_list_key, version_keys
+        Discourse.redis.rpush missing_versions_list_key, version_keys
       end
 
       versions || []
     end
 
     def missing_versions
-      keys = $redis.lrange(missing_versions_list_key, 0, 4) # max of 5 versions
-      keys.present? ? keys.map { |k| $redis.hgetall(k) } : []
+      keys = Discourse.redis.lrange(missing_versions_list_key, 0, 4) # max of 5 versions
+      keys.present? ? keys.map { |k| Discourse.redis.hgetall(k) } : []
     end
 
     private

lib/distributed_memoizer.rb

@@ -8,7 +8,7 @@ class DistributedMemoizer
 
   # memoize a key across processes and machines
   def self.memoize(key, duration = 60 * 60 * 24, redis = nil)
-    redis ||= $redis
+    redis ||= Discourse.redis
 
     redis_key = self.redis_key(key)
 
@@ -50,7 +50,7 @@ class DistributedMemoizer
 
   # Used for testing
   def self.flush!
-    $redis.scan_each(match: "memoize_*").each { |key| $redis.del(key) }
+    Discourse.redis.scan_each(match: "memoize_*").each { |key| Discourse.redis.del(key) }
   end
 
   protected

lib/distributed_mutex.rb

@@ -17,7 +17,7 @@ class DistributedMutex
   def initialize(key, redis: nil, validity: DEFAULT_VALIDITY)
     @key = key
     @using_global_redis = true if !redis
-    @redis = redis || $redis
+    @redis = redis || Discourse.redis
     @mutex = Mutex.new
     @validity = validity
   end

lib/email/processor.rb

@@ -119,8 +119,8 @@ module Email
 
       key = "rejection_email:#{email}:#{type}:#{Date.today}"
 
-      if $redis.setnx(key, "1")
-        $redis.expire(key, 25.hours)
+      if Discourse.redis.setnx(key, "1")
+        Discourse.redis.expire(key, 25.hours)
         true
       else
         false

lib/email_backup_token.rb

@@ -12,16 +12,16 @@ class EmailBackupToken
 
   def self.set(user_id)
     token = self.generate
-    $redis.setex self.key(user_id), 1.day.to_i, token
+    Discourse.redis.setex self.key(user_id), 1.day.to_i, token
     token
   end
 
   def self.get(user_id)
-    $redis.get self.key(user_id)
+    Discourse.redis.get self.key(user_id)
   end
 
   def self.del(user_id)
-    $redis.del self.key(user_id)
+    Discourse.redis.del self.key(user_id)
   end
 
   def self.compare(user_id, token)

lib/final_destination.rb

@@ -11,17 +11,17 @@ class FinalDestination
 
   def self.clear_https_cache!(domain)
     key = redis_https_key(domain)
-    $redis.without_namespace.del(key)
+    Discourse.redis.without_namespace.del(key)
   end
 
   def self.cache_https_domain(domain)
     key = redis_https_key(domain)
-    $redis.without_namespace.setex(key, "1", 1.day.to_i).present?
+    Discourse.redis.without_namespace.setex(key, "1", 1.day.to_i).present?
   end
 
   def self.is_https_domain?(domain)
     key = redis_https_key(domain)
-    $redis.without_namespace.get(key).present?
+    Discourse.redis.without_namespace.get(key).present?
   end
 
   def self.redis_https_key(domain)

lib/middleware/anonymous_cache.rb

@@ -177,8 +177,8 @@ module Middleware
       end
 
       def cached(env = {})
-        if body = decompress($redis.get(cache_key_body))
-          if other = $redis.get(cache_key_other)
+        if body = decompress(Discourse.redis.get(cache_key_body))
+          if other = Discourse.redis.get(cache_key_other)
             other = JSON.parse(other)
             if req_params = other[1].delete(ADP)
               env[ADP] = req_params
@@ -203,7 +203,7 @@ module Middleware
         if status == 200 && cache_duration
 
           if GlobalSetting.anon_cache_store_threshold > 1
-            count = $redis.eval(<<~REDIS, [cache_key_count], [cache_duration])
+            count = Discourse.redis.eval(<<~REDIS, [cache_key_count], [cache_duration])
               local current = redis.call("incr", KEYS[1])
               redis.call("expire",KEYS[1],ARGV[1])
               return current
@@ -231,8 +231,8 @@ module Middleware
             }
           end
 
-          $redis.setex(cache_key_body,  cache_duration, compress(parts.join))
-          $redis.setex(cache_key_other, cache_duration, [status, headers_stripped].to_json)
+          Discourse.redis.setex(cache_key_body,  cache_duration, compress(parts.join))
+          Discourse.redis.setex(cache_key_other, cache_duration, [status, headers_stripped].to_json)
 
           headers["X-Discourse-Cached"] = "store"
         else
@@ -243,8 +243,8 @@ module Middleware
       end
 
       def clear_cache
-        $redis.del(cache_key_body)
-        $redis.del(cache_key_other)
+        Discourse.redis.del(cache_key_body)
+        Discourse.redis.del(cache_key_other)
       end
 
     end

lib/oneboxer.rb

@@ -122,15 +122,15 @@ module Oneboxer
   end
 
   def self.is_previewing?(user_id)
-    $redis.get(preview_key(user_id)) == "1"
+    Discourse.redis.get(preview_key(user_id)) == "1"
   end
 
   def self.preview_onebox!(user_id)
-    $redis.setex(preview_key(user_id), 1.minute, "1")
+    Discourse.redis.setex(preview_key(user_id), 1.minute, "1")
   end
 
   def self.onebox_previewed!(user_id)
-    $redis.del(preview_key(user_id))
+    Discourse.redis.del(preview_key(user_id))
   end
 
   def self.engine(url)

lib/post_revisor.rb

@@ -265,11 +265,11 @@ class PostRevisor
   end
 
   def cached_original_raw
-    @cached_original_raw ||= $redis.get(original_raw_key)
+    @cached_original_raw ||= Discourse.redis.get(original_raw_key)
   end
 
   def cached_original_cooked
-    @cached_original_cooked ||= $redis.get(original_cooked_key)
+    @cached_original_cooked ||= Discourse.redis.get(original_cooked_key)
   end
 
   def original_raw
@@ -278,12 +278,12 @@ class PostRevisor
 
   def original_raw=(val)
     @cached_original_raw = val
-    $redis.setex(original_raw_key, SiteSetting.editing_grace_period + 1, val)
+    Discourse.redis.setex(original_raw_key, SiteSetting.editing_grace_period + 1, val)
   end
 
   def original_cooked=(val)
     @cached_original_cooked = val
-    $redis.setex(original_cooked_key, SiteSetting.editing_grace_period + 1, val)
+    Discourse.redis.setex(original_cooked_key, SiteSetting.editing_grace_period + 1, val)
   end
 
   def diff_size(before, after)

lib/rate_limiter.rb

@@ -24,12 +24,12 @@ class RateLimiter
 
   # Only used in test, only clears current namespace, does not clear globals
   def self.clear_all!
-    $redis.delete_prefixed(RateLimiter.key_prefix)
+    Discourse.redis.delete_prefixed(RateLimiter.key_prefix)
   end
 
   def self.clear_all_global!
-    $redis.without_namespace.keys("GLOBAL::#{key_prefix}*").each do |k|
-      $redis.without_namespace.del k
+    Discourse.redis.without_namespace.keys("GLOBAL::#{key_prefix}*").each do |k|
+      Discourse.redis.without_namespace.del k
     end
   end
 
@@ -119,12 +119,12 @@ class RateLimiter
     if @global
       "GLOBAL::#{key}"
     else
-      $redis.namespace_key(key)
+      Discourse.redis.namespace_key(key)
     end
   end
 
   def redis
-    $redis.without_namespace
+    Discourse.redis.without_namespace
   end
 
   def seconds_to_wait

lib/secure_session.rb

@@ -16,23 +16,23 @@ class SecureSession
 
   def set(key, val, expires: nil)
     expires ||= SecureSession.expiry
-    $redis.setex(prefixed_key(key), expires.to_i, val.to_s)
+    Discourse.redis.setex(prefixed_key(key), expires.to_i, val.to_s)
     true
   end
 
   def ttl(key)
-    $redis.ttl(prefixed_key(key))
+    Discourse.redis.ttl(prefixed_key(key))
   end
 
   def [](key)
-    $redis.get(prefixed_key(key))
+    Discourse.redis.get(prefixed_key(key))
   end
 
   def []=(key, val)
     if val == nil
-      $redis.del(prefixed_key(key))
+      Discourse.redis.del(prefixed_key(key))
     else
-      $redis.setex(prefixed_key(key), SecureSession.expiry.to_i, val.to_s)
+      Discourse.redis.setex(prefixed_key(key), SecureSession.expiry.to_i, val.to_s)
     end
     val
   end

lib/sidekiq/pausable.rb

@@ -12,13 +12,13 @@ class SidekiqPauser
   end
 
   def pause!(value = "paused")
-    $redis.setex PAUSED_KEY, TTL, value
+    Discourse.redis.setex PAUSED_KEY, TTL, value
     extend_lease_thread
     true
   end
 
   def paused?
-    !!$redis.get(PAUSED_KEY)
+    !!Discourse.redis.get(PAUSED_KEY)
   end
 
   def unpause_all!
@@ -48,7 +48,7 @@ class SidekiqPauser
       stop_extend_lease_thread if @dbs.size == 0
     end
 
-    $redis.del(PAUSED_KEY)
+    Discourse.redis.del(PAUSED_KEY)
     true
   end
 
@@ -83,7 +83,7 @@ class SidekiqPauser
           @mutex.synchronize do
             @dbs.each do |db|
               RailsMultisite::ConnectionManagement.with_connection(db) do
-                if !$redis.expire(PAUSED_KEY, TTL)
+                if !Discourse.redis.expire(PAUSED_KEY, TTL)
                   # if it was unpaused in another process we got to remove the
                   # bad key
                   @dbs.delete(db)

lib/stylesheet/watcher.rb

@@ -7,11 +7,11 @@ module Stylesheet
     REDIS_KEY = "dev_last_used_theme_id"
 
     def self.theme_id=(v)
-      $redis.set(REDIS_KEY, v)
+      Discourse.redis.set(REDIS_KEY, v)
     end
 
     def self.theme_id
-      ($redis.get(REDIS_KEY) || SiteSetting.default_theme_id).to_i
+      (Discourse.redis.get(REDIS_KEY) || SiteSetting.default_theme_id).to_i
     end
 
     def self.watch(paths = nil)

lib/tasks/redis.rake

@@ -9,7 +9,7 @@ task 'redis:clean_up' => ['environment'] do
   regexp = /((\$(?<message_bus>\w+)$)|(^?(?<namespace>\w+):))/
 
   cursor = 0
-  redis = $redis.without_namespace
+  redis = Discourse.redis.without_namespace
 
   loop do
     cursor, keys = redis.scan(cursor)

lib/tasks/typepad.thor

@@ -161,11 +161,11 @@ class Typepad < Thor
 
         if options[:google_api] && comment[:author] =~ /plus.google.com\/(\d+)/
           gplus_id = Regexp.last_match[1]
-          from_redis = $redis.get("gplus:#{gplus_id}")
+          from_redis = Discourse.redis.get("gplus:#{gplus_id}")
           if from_redis.blank?
             json = ::JSON.parse(open("https://www.googleapis.com/plus/v1/people/#{gplus_id}?key=#{options[:google_api]}").read)
             from_redis = json['displayName']
-            $redis.set("gplus:#{gplus_id}", from_redis)
+            Discourse.redis.set("gplus:#{gplus_id}", from_redis)
           end
           comment[:author] = from_redis
         end
@@ -184,11 +184,11 @@ class Typepad < Thor
 
         if comment[:author] =~ /www.facebook.com\/profile.php\?id=(\d+)/
           fb_id = Regexp.last_match[1]
-          from_redis = $redis.get("fb:#{fb_id}")
+          from_redis = Discourse.redis.get("fb:#{fb_id}")
           if from_redis.blank?
             json = ::JSON.parse(open("http://graph.facebook.com/#{fb_id}").read)
             from_redis = json['username']
-            $redis.set("fb:#{fb_id}", from_redis)
+            Discourse.redis.set("fb:#{fb_id}", from_redis)
           end
           comment[:author] = from_redis
         end

lib/topic_retriever.rb

@@ -24,8 +24,8 @@ class TopicRetriever
 
     # Throttle other users to once every 60 seconds
     retrieved_key = "retrieved_topic"
-    if $redis.setnx(retrieved_key, "1")
-      $redis.expire(retrieved_key, 60)
+    if Discourse.redis.setnx(retrieved_key, "1")
+      Discourse.redis.expire(retrieved_key, 60)
       return false
     end
 

plugins/discourse-narrative-bot/lib/discourse_narrative_bot/actions.rb

@@ -51,15 +51,15 @@ module DiscourseNarrativeBot
 
       key = "#{DiscourseNarrativeBot::PLUGIN_NAME}:reset-rate-limit:#{post.topic_id}:#{data['state']}"
 
-      if !(count = $redis.get(key))
+      if !(count = Discourse.redis.get(key))
         count = 0
-        $redis.setex(key, duration, count)
+        Discourse.redis.setex(key, duration, count)
       end
 
       if count.to_i < 2
         post.default_rate_limiter.rollback!
         post.limit_posts_per_day&.rollback!
-        $redis.incr(key)
+        Discourse.redis.incr(key)
       end
     end
 

plugins/discourse-narrative-bot/lib/discourse_narrative_bot/track_selector.rb

@@ -53,7 +53,7 @@ module DiscourseNarrativeBot
             if previous_status && data[:attempted] == previous_status && !data[:skip_attempted]
               generic_replies(klass.reset_trigger, state)
             else
-              $redis.del(generic_replies_key(@user))
+              Discourse.redis.del(generic_replies_key(@user))
             end
 
             Store.set(@user.id, data)
@@ -143,14 +143,14 @@ module DiscourseNarrativeBot
 
           if public_reply?
             key = "#{PUBLIC_DISPLAY_BOT_HELP_KEY}:#{@post.topic_id}"
-            last_bot_help_post_number = $redis.get(key)
+            last_bot_help_post_number = Discourse.redis.get(key)
 
             if !last_bot_help_post_number ||
                 (last_bot_help_post_number &&
                  @post.post_number - 10 > last_bot_help_post_number.to_i &&
-                 (1.day.to_i - $redis.ttl(key)) > 6.hours.to_i)
+                 (1.day.to_i - Discourse.redis.ttl(key)) > 6.hours.to_i)
 
-              $redis.setex(key, 1.day.to_i, @post.post_number)
+              Discourse.redis.setex(key, 1.day.to_i, @post.post_number)
               message
             end
           else
@@ -190,7 +190,7 @@ module DiscourseNarrativeBot
     def generic_replies(track_reset_trigger, state = nil)
       reset_trigger = "#{self.class.reset_trigger} #{track_reset_trigger}"
       key = generic_replies_key(@user)
-      count = ($redis.get(key) || $redis.setex(key, 900, 0)).to_i
+      count = (Discourse.redis.get(key) || Discourse.redis.setex(key, 900, 0)).to_i
 
       case count
       when 0
@@ -210,7 +210,7 @@ module DiscourseNarrativeBot
         # Stay out of the user's way
       end
 
-      $redis.incr(key)
+      Discourse.redis.incr(key)
     end
 
     def self.i18n_key(key)

plugins/discourse-narrative-bot/spec/discourse_narrative_bot/track_selector_spec.rb

@@ -243,7 +243,7 @@ describe DiscourseNarrativeBot::TrackSelector do
 
         context 'generic replies' do
           after do
-            $redis.del("#{described_class::GENERIC_REPLIES_COUNT_PREFIX}#{user.id}")
+            Discourse.redis.del("#{described_class::GENERIC_REPLIES_COUNT_PREFIX}#{user.id}")
           end
 
           it 'should create the right generic do not understand responses' do
@@ -472,17 +472,17 @@ describe DiscourseNarrativeBot::TrackSelector do
           let(:post) { Fabricate(:post, topic: topic) }
 
           after do
-            $redis.flushall
+            Discourse.redis.flushall
           end
 
           describe 'when random reply massage has been displayed in the last 6 hours' do
             it 'should not do anything' do
-              $redis.set(
+              Discourse.redis.set(
                 "#{described_class::PUBLIC_DISPLAY_BOT_HELP_KEY}:#{other_post.topic_id}",
                 post.post_number - 11
               )
 
-              $redis.class.any_instance.expects(:ttl).returns(19.hours.to_i)
+              Discourse.redis.class.any_instance.expects(:ttl).returns(19.hours.to_i)
 
               user
               post.update!(raw: "Show me what you can do @discobot")
@@ -494,12 +494,12 @@ describe DiscourseNarrativeBot::TrackSelector do
 
           describe 'when random reply message has not been displayed in the last 6 hours' do
             it 'should create the right reply' do
-              $redis.set(
+              Discourse.redis.set(
                 "#{described_class::PUBLIC_DISPLAY_BOT_HELP_KEY}:#{other_post.topic_id}",
                 post.post_number - 11
               )
 
-              $redis.class.any_instance.expects(:ttl).returns(7.hours.to_i)
+              Discourse.redis.class.any_instance.expects(:ttl).returns(7.hours.to_i)
 
               user
               post.update!(raw: "Show me what you can do @discobot")
@@ -515,7 +515,7 @@ describe DiscourseNarrativeBot::TrackSelector do
               described_class.new(:reply, user, post_id: other_post.id).select
               expect(Post.last.raw).to eq(random_mention_reply)
 
-              expect($redis.get(
+              expect(Discourse.redis.get(
                 "#{described_class::PUBLIC_DISPLAY_BOT_HELP_KEY}:#{other_post.topic_id}"
               ).to_i).to eq(other_post.post_number.to_i)
 

plugins/discourse-presence/plugin.rb

@@ -36,20 +36,20 @@ after_initialize do
     # return true if a key was added
     def self.add(type, id, user_id)
       key = get_redis_key(type, id)
-      result = $redis.hset(key, user_id, Time.zone.now)
-      $redis.expire(key, MAX_BACKLOG_AGE)
+      result = Discourse.redis.hset(key, user_id, Time.zone.now)
+      Discourse.redis.expire(key, MAX_BACKLOG_AGE)
       result
     end
 
     # return true if a key was deleted
     def self.remove(type, id, user_id)
       key = get_redis_key(type, id)
-      $redis.expire(key, MAX_BACKLOG_AGE)
-      $redis.hdel(key, user_id) > 0
+      Discourse.redis.expire(key, MAX_BACKLOG_AGE)
+      Discourse.redis.hdel(key, user_id) > 0
     end
 
     def self.get_users(type, id)
-      user_ids = $redis.hkeys(get_redis_key(type, id)).map(&:to_i)
+      user_ids = Discourse.redis.hkeys(get_redis_key(type, id)).map(&:to_i)
       User.where(id: user_ids)
     end
 
@@ -88,7 +88,7 @@ after_initialize do
       has_changed = false
 
       # Delete entries older than 20 seconds
-      hash = $redis.hgetall(get_redis_key(type, id))
+      hash = Discourse.redis.hgetall(get_redis_key(type, id))
       hash.each do |user_id, time|
         if Time.zone.now - Time.parse(time) >= 20
           has_changed |= remove(type, id, user_id)

plugins/discourse-presence/spec/presence_manager_spec.rb

@@ -13,10 +13,10 @@ describe ::Presence::PresenceManager do
   let(:post2) { Fabricate(:post) }
 
   after(:each) do
-    $redis.del("presence:topic:#{post1.topic.id}")
-    $redis.del("presence:topic:#{post2.topic.id}")
-    $redis.del("presence:post:#{post1.id}")
-    $redis.del("presence:post:#{post2.id}")
+    Discourse.redis.del("presence:topic:#{post1.topic.id}")
+    Discourse.redis.del("presence:topic:#{post2.topic.id}")
+    Discourse.redis.del("presence:post:#{post1.id}")
+    Discourse.redis.del("presence:post:#{post2.id}")
   end
 
   it 'adds, removes and lists users correctly' do

plugins/discourse-presence/spec/requests/presence_controller_spec.rb

@@ -17,10 +17,10 @@ describe ::Presence::PresencesController do
   let(:manager) { ::Presence::PresenceManager }
 
   after do
-    $redis.del("presence:topic:#{post1.topic.id}")
-    $redis.del("presence:topic:#{post2.topic.id}")
-    $redis.del("presence:post:#{post1.id}")
-    $redis.del("presence:post:#{post2.id}")
+    Discourse.redis.del("presence:topic:#{post1.topic.id}")
+    Discourse.redis.del("presence:topic:#{post2.topic.id}")
+    Discourse.redis.del("presence:post:#{post1.id}")
+    Discourse.redis.del("presence:post:#{post2.id}")
   end
 
   context 'when not logged in' do

script/benchmarks/cache/bench.rb

@@ -7,14 +7,14 @@ Benchmark.ips do |x|
 
   x.report("redis setex string") do |times|
     while times > 0
-      $redis.setex("test_key", 60, "test")
+      Discourse.redis.setex("test_key", 60, "test")
       times -= 1
     end
   end
 
   x.report("redis setex marshal string") do |times|
     while times > 0
-      $redis.setex("test_keym", 60, Marshal.dump("test"))
+      Discourse.redis.setex("test_keym", 60, Marshal.dump("test"))
       times -= 1
     end
   end
@@ -39,14 +39,14 @@ end
 Benchmark.ips do |x|
   x.report("redis get string") do |times|
     while times > 0
-      $redis.get("test_key")
+      Discourse.redis.get("test_key")
       times -= 1
     end
   end
 
   x.report("redis get string marshal") do |times|
     while times > 0
-      Marshal.load($redis.get("test_keym"))
+      Marshal.load(Discourse.redis.get("test_keym"))
       times -= 1
     end
   end

script/redis_memory.rb

@@ -2,7 +2,7 @@
 
 require File.expand_path("../../config/environment", __FILE__)
 
-@redis = $redis.without_namespace
+@redis = Discourse.redis.without_namespace
 
 stats = {}
 

spec/components/active_record/connection_adapters/postgresql_fallback_adapter_spec.rb

@@ -41,7 +41,7 @@ describe ActiveRecord::ConnectionHandling do
     ActiveRecord::Base.clear_all_connections!
     ActiveRecord::Base.establish_connection
 
-    $redis.flushall
+    Discourse.redis.flushall
   end
 
   describe "#postgresql_fallback_connection" do

spec/components/auth/default_current_user_provider_spec.rb

@@ -399,7 +399,7 @@ describe Auth::DefaultCurrentUserProvider do
     end
 
     after do
-      $redis.flushall
+      Discourse.redis.flushall
     end
 
     it "should not update last seen for suspended users" do
@@ -416,7 +416,7 @@ describe Auth::DefaultCurrentUserProvider do
       u.suspended_till = 1.year.from_now
       u.save!
 
-      $redis.del("user:#{user.id}:#{Time.now.to_date}")
+      Discourse.redis.del("user:#{user.id}:#{Time.now.to_date}")
       provider2 = provider("/", "HTTP_COOKIE" => "_t=#{unhashed_token}")
       expect(provider2.current_user).to eq(nil)
 

spec/components/cache_spec.rb

@@ -32,12 +32,12 @@ describe Cache do
   end
 
   it "can be cleared" do
-    $redis.set("boo", "boo")
+    Discourse.redis.set("boo", "boo")
     cache.write("hello0", "world")
     cache.write("hello1", "world")
     cache.clear
 
-    expect($redis.get("boo")).to eq("boo")
+    expect(Discourse.redis.get("boo")).to eq("boo")
     expect(cache.read("hello0")).to eq(nil)
   end
 
@@ -64,13 +64,13 @@ describe Cache do
       "bob"
     end
 
-    expect($redis.ttl(key)).to be_within(2.seconds).of(1.minute)
+    expect(Discourse.redis.ttl(key)).to be_within(2.seconds).of(1.minute)
 
     # we always expire withing a day
     cache.fetch("bla") { "hi" }
 
     key = cache.normalize_key("bla")
-    expect($redis.ttl(key)).to be_within(2.seconds).of(1.day)
+    expect(Discourse.redis.ttl(key)).to be_within(2.seconds).of(1.day)
   end
 
   it "can store and fetch correctly" do

spec/components/discourse_redis_spec.rb

@@ -101,12 +101,12 @@ describe DiscourseRedis do
     it 'should check the status of the master server' do
       begin
         fallback_handler.master = false
-        $redis.without_namespace.expects(:set).raises(Redis::CommandError.new("READONLY"))
+        Discourse.redis.without_namespace.expects(:set).raises(Redis::CommandError.new("READONLY"))
         fallback_handler.expects(:verify_master).once
-        $redis.set('test', '1')
+        Discourse.redis.set('test', '1')
       ensure
         fallback_handler.master = true
-        $redis.del('test')
+        Discourse.redis.del('test')
       end
     end
   end

spec/components/discourse_spec.rb

@@ -185,21 +185,21 @@ describe Discourse do
     let(:user_readonly_mode_key) { Discourse::USER_READONLY_MODE_KEY }
 
     after do
-      $redis.del(readonly_mode_key)
-      $redis.del(user_readonly_mode_key)
+      Discourse.redis.del(readonly_mode_key)
+      Discourse.redis.del(user_readonly_mode_key)
     end
 
     def assert_readonly_mode(message, key, ttl = -1)
       expect(message.channel).to eq(Discourse.readonly_channel)
       expect(message.data).to eq(true)
-      expect($redis.get(key)).to eq("1")
-      expect($redis.ttl(key)).to eq(ttl)
+      expect(Discourse.redis.get(key)).to eq("1")
+      expect(Discourse.redis.ttl(key)).to eq(ttl)
     end
 
     def assert_readonly_mode_disabled(message, key)
       expect(message.channel).to eq(Discourse.readonly_channel)
       expect(message.data).to eq(false)
-      expect($redis.get(key)).to eq(nil)
+      expect(Discourse.redis.get(key)).to eq(nil)
     end
 
     def get_readonly_message
@@ -217,14 +217,14 @@ describe Discourse do
 
     describe ".enable_readonly_mode" do
       it "adds a key in redis and publish a message through the message bus" do
-        expect($redis.get(readonly_mode_key)).to eq(nil)
+        expect(Discourse.redis.get(readonly_mode_key)).to eq(nil)
         message = get_readonly_message { Discourse.enable_readonly_mode }
         assert_readonly_mode(message, readonly_mode_key, readonly_mode_ttl)
       end
 
       context 'user enabled readonly mode' do
         it "adds a key in redis and publish a message through the message bus" do
-          expect($redis.get(user_readonly_mode_key)).to eq(nil)
+          expect(Discourse.redis.get(user_readonly_mode_key)).to eq(nil)
           message = get_readonly_message { Discourse.enable_readonly_mode(user_readonly_mode_key) }
           assert_readonly_mode(message, user_readonly_mode_key)
         end
@@ -252,7 +252,7 @@ describe Discourse do
       end
 
       it "returns true when the key is present in redis" do
-        $redis.set(readonly_mode_key, 1)
+        Discourse.redis.set(readonly_mode_key, 1)
         expect(Discourse.readonly_mode?).to eq(true)
       end
 

spec/components/distributed_memoizer_spec.rb

@@ -5,9 +5,9 @@ require 'rails_helper'
 describe DistributedMemoizer do
 
   before do
-    $redis.del(DistributedMemoizer.redis_key("hello"))
-    $redis.del(DistributedMemoizer.redis_lock_key("hello"))
-    $redis.unwatch
+    Discourse.redis.del(DistributedMemoizer.redis_key("hello"))
+    Discourse.redis.del(DistributedMemoizer.redis_lock_key("hello"))
+    Discourse.redis.unwatch
   end
 
   # NOTE we could use a mock redis here, but I think it makes sense to test the real thing

spec/components/distributed_mutex_spec.rb

@@ -6,7 +6,7 @@ describe DistributedMutex do
   let(:key) { "test_mutex_key" }
 
   after do
-    $redis.del(key)
+    Discourse.redis.del(key)
   end
 
   it "allows only one mutex object to have the lock at a time" do
@@ -31,7 +31,7 @@ describe DistributedMutex do
   it "handles auto cleanup correctly" do
     m = DistributedMutex.new(key)
 
-    $redis.setnx key, Time.now.to_i - 1
+    Discourse.redis.setnx key, Time.now.to_i - 1
 
     start = Time.now.to_i
     m.synchronize do
@@ -54,16 +54,16 @@ describe DistributedMutex do
     mutex = DistributedMutex.new(key, validity: 2)
 
     mutex.synchronize do
-      expect($redis.ttl(key)).to eq(2)
-      expect($redis.get(key).to_i).to eq(Time.now.to_i + 2)
+      expect(Discourse.redis.ttl(key)).to eq(2)
+      expect(Discourse.redis.get(key).to_i).to eq(Time.now.to_i + 2)
     end
 
     mutex = DistributedMutex.new(key)
 
     mutex.synchronize do
-      expect($redis.ttl(key)).to eq(DistributedMutex::DEFAULT_VALIDITY)
+      expect(Discourse.redis.ttl(key)).to eq(DistributedMutex::DEFAULT_VALIDITY)
 
-      expect($redis.get(key).to_i)
+      expect(Discourse.redis.get(key).to_i)
         .to eq(Time.now.to_i + DistributedMutex::DEFAULT_VALIDITY)
     end
   end
@@ -80,11 +80,11 @@ describe DistributedMutex do
 
   context "readonly redis" do
     before do
-      $redis.slaveof "127.0.0.1", "99991"
+      Discourse.redis.slaveof "127.0.0.1", "99991"
     end
 
     after do
-      $redis.slaveof "no", "one"
+      Discourse.redis.slaveof "no", "one"
     end
 
     it "works even if redis is in readonly" do
@@ -111,7 +111,7 @@ describe DistributedMutex do
         Concurrency::Scenario.new do |execution|
           locked = false
 
-          $redis.del('mutex_key')
+          Discourse.redis.del('mutex_key')
 
           connections.each do |connection|
             connection.unwatch

spec/components/email/processor_spec.rb

@@ -5,7 +5,7 @@ require "email/processor"
 
 describe Email::Processor do
   after do
-    $redis.flushall
+    Discourse.redis.flushall
   end
 
   let(:from) { "foo@bar.com" }
@@ -78,7 +78,7 @@ describe Email::Processor do
 
     it "only sends one rejection email per day" do
       key = "rejection_email:#{[from]}:email_reject_empty:#{Date.today}"
-      $redis.expire(key, 0)
+      Discourse.redis.expire(key, 0)
 
       expect {
         Email::Processor.process!(mail)
@@ -91,7 +91,7 @@ describe Email::Processor do
       freeze_time(Date.today + 1)
 
       key = "rejection_email:#{[from]}:email_reject_empty:#{Date.today}"
-      $redis.expire(key, 0)
+      Discourse.redis.expire(key, 0)
 
       expect {
         Email::Processor.process!(mail3)
@@ -131,7 +131,7 @@ describe Email::Processor do
     it "sends more than one rejection email per day" do
       Email::Receiver.any_instance.stubs(:process_internal).raises("boom")
       key = "rejection_email:#{[from]}:email_reject_unrecognized_error:#{Date.today}"
-      $redis.expire(key, 0)
+      Discourse.redis.expire(key, 0)
 
       expect {
         Email::Processor.process!(mail)

spec/components/middleware/anonymous_cache_spec.rb

@@ -143,7 +143,7 @@ describe Middleware::AnonymousCache::Helper do
 
       # depends on i7z implementation, but lets assume it is stable unless we discover
       # otherwise
-      expect($redis.get(helper.cache_key_body).length).to eq(16)
+      expect(Discourse.redis.get(helper.cache_key_body).length).to eq(16)
     end
 
     it "handles brotli switching" do

spec/components/middleware/request_tracker_spec.rb

@@ -264,7 +264,7 @@ describe Middleware::RequestTracker do
           User.where(id: -100).pluck(:id)
         end
         redis_calls.times do
-          $redis.get("x")
+          Discourse.redis.get("x")
         end
         result
       end

spec/components/post_revisor_spec.rb

@@ -91,7 +91,7 @@ describe PostRevisor do
     before do
       # There used to be a bug where wiki changes were considered posting "too similar"
       # so this is enabled and checked
-      $redis.delete_prefixed('unique-post')
+      Discourse.redis.delete_prefixed('unique-post')
       SiteSetting.unique_posts_mins = 10
     end
 

spec/components/pretty_text_spec.rb

@@ -456,7 +456,7 @@ describe PrettyText do
         ['apple', 'banana'].each { |w| Fabricate(:watched_word, word: w, action: WatchedWord.actions[:censor]) }
         expect(PrettyText.cook("# banana")).not_to include('banana')
       ensure
-        $redis.flushall
+        Discourse.redis.flushall
       end
     end
   end
@@ -1091,7 +1091,7 @@ HTML
   end
 
   describe "censoring" do
-    after(:all) { $redis.flushall }
+    after(:all) { Discourse.redis.flushall }
 
     def expect_cooked_match(raw, expected_cooked)
       expect(PrettyText.cook(raw)).to eq(expected_cooked)

spec/components/rate_limiter_spec.rb

@@ -63,11 +63,11 @@ describe RateLimiter do
 
     context 'handles readonly' do
       before do
-        $redis.without_namespace.slaveof '10.0.0.1', '99999'
+        Discourse.redis.without_namespace.slaveof '10.0.0.1', '99999'
       end
 
       after do
-        $redis.without_namespace.slaveof 'no', 'one'
+        Discourse.redis.without_namespace.slaveof 'no', 'one'
       end
 
       it 'does not explode' do

spec/components/topic_query_spec.rb

@@ -767,7 +767,7 @@ describe TopicQuery do
 
   context 'suggested_for' do
     def clear_cache!
-      $redis.keys('random_topic_cache*').each { |k| $redis.del k }
+      Discourse.redis.keys('random_topic_cache*').each { |k| Discourse.redis.del k }
     end
 
     before do

spec/components/validators/post_validator_spec.rb

@@ -198,7 +198,7 @@ describe PostValidator do
     end
 
     after do
-      $redis.del(@key)
+      Discourse.redis.del(@key)
     end
 
     context "post is unique" do

spec/jobs/about_stats_spec.rb

@@ -7,12 +7,12 @@ describe Jobs::AboutStats do
     begin
       stats = About.fetch_stats.to_json
       cache_key = About.stats_cache_key
-      $redis.del(cache_key)
+      Discourse.redis.del(cache_key)
 
       expect(described_class.new.execute({})).to eq(stats)
-      expect($redis.get(cache_key)).to eq(stats)
+      expect(Discourse.redis.get(cache_key)).to eq(stats)
     ensure
-      $redis.del(cache_key)
+      Discourse.redis.del(cache_key)
     end
   end
 end

spec/jobs/poll_mailbox_spec.rb

@@ -30,7 +30,7 @@ describe Jobs::PollMailbox do
       end
 
       after do
-        $redis.del(Jobs::PollMailbox::POLL_MAILBOX_TIMEOUT_ERROR_KEY)
+        Discourse.redis.del(Jobs::PollMailbox::POLL_MAILBOX_TIMEOUT_ERROR_KEY)
       end
 
       it "add an admin dashboard message on pop authentication error" do

spec/mailers/user_notifications_spec.rb

@@ -108,7 +108,7 @@ describe UserNotifications do
     subject { UserNotifications.digest(user) }
 
     after do
-      $redis.keys('summary-new-users:*').each { |key| $redis.del(key) }
+      Discourse.redis.keys('summary-new-users:*').each { |key| Discourse.redis.del(key) }
     end
 
     context "without new topics" do

spec/models/application_request_spec.rb

@@ -5,7 +5,7 @@ require 'rails_helper'
 describe ApplicationRequest do
   before do
     ApplicationRequest.last_flush = Time.now.utc
-    $redis.flushall
+    Discourse.redis.flushall
   end
 
   after do
@@ -28,15 +28,15 @@ describe ApplicationRequest do
       inc(:http_total)
       inc(:http_total)
 
-      $redis.without_namespace.stubs(:incr).raises(Redis::CommandError.new("READONLY"))
-      $redis.without_namespace.stubs(:eval).raises(Redis::CommandError.new("READONLY"))
+      Discourse.redis.without_namespace.stubs(:incr).raises(Redis::CommandError.new("READONLY"))
+      Discourse.redis.without_namespace.stubs(:eval).raises(Redis::CommandError.new("READONLY"))
 
       # flush will be deferred no error raised
       inc(:http_total, autoflush: 3)
       ApplicationRequest.write_cache!
 
-      $redis.without_namespace.unstub(:incr)
-      $redis.without_namespace.unstub(:eval)
+      Discourse.redis.without_namespace.unstub(:incr)
+      Discourse.redis.without_namespace.unstub(:eval)
 
       inc(:http_total, autoflush: 3)
       expect(ApplicationRequest.http_total.first.count).to eq(3)

spec/models/global_setting_spec.rb

@@ -35,18 +35,18 @@ describe GlobalSetting do
       freeze_time Time.now
 
       token = GlobalSetting.safe_secret_key_base
-      $redis.without_namespace.del(GlobalSetting::REDIS_SECRET_KEY)
+      Discourse.redis.without_namespace.del(GlobalSetting::REDIS_SECRET_KEY)
       freeze_time Time.now + 20
 
       GlobalSetting.safe_secret_key_base
-      new_token = $redis.without_namespace.get(GlobalSetting::REDIS_SECRET_KEY)
+      new_token = Discourse.redis.without_namespace.get(GlobalSetting::REDIS_SECRET_KEY)
       expect(new_token).to eq(nil)
 
       freeze_time Time.now + 11
 
       GlobalSetting.safe_secret_key_base
 
-      new_token = $redis.without_namespace.get(GlobalSetting::REDIS_SECRET_KEY)
+      new_token = Discourse.redis.without_namespace.get(GlobalSetting::REDIS_SECRET_KEY)
       expect(new_token).to eq(token)
 
     end

spec/models/search_log_spec.rb

@@ -128,7 +128,7 @@ RSpec.describe SearchLog, type: :model do
         expect(action).to eq(:created)
 
         freeze_time(10.minutes.from_now)
-        $redis.del(SearchLog.redis_key(ip_address: '192.168.0.1', user_id: user.id))
+        Discourse.redis.del(SearchLog.redis_key(ip_address: '192.168.0.1', user_id: user.id))
 
         action, _ = SearchLog.log(
           term: 'hello',