DEV: Don't allow users to immediately reinvite (#15722)

- Limit bulk re-invite to 1 time per day
- Move bulk invite by csv behind a site setting (hidden by default)
- Bump invite expiry from 30 -> 90 days

## Updates to rate_limiter
When limiting reinvites I found that **staff** are never limited in any way. So I updated the **rate_limiter** model to allow for a few things:
- add an optional param of `staff_limit`, which (when included and passed values, and the user passes `.staff?`) will override the default `max` & `secs` values and apply them to the user.
- in the case you **do** pass values to `staff_limit` but the user **does not** pass `staff?` the standard `max` & `secs` values will be applied to the user.

This should give us enough flexibility to 
1. continue to apply a strict rate limit to a standard user
2. but also apply a secondary (less strict) limit to staff

app/assets/javascripts/discourse/app/templates/user-invited-show.hbs

@@ -10,9 +10,11 @@
         {{#d-section class="user-invite-buttons"}}
           {{d-button class="btn-default" icon="plus" action=(action "createInvite") label="user.invited.create"}}
           {{#if canBulkInvite}}
-            {{#unless site.mobileView}}
-              {{d-button class="btn-default" icon="upload" action=(action "createInviteCsv") label="user.invited.bulk_invite.text"}}
-            {{/unless}}
+            {{#if siteSettings.allow_bulk_invite}}
+              {{#unless site.mobileView}}
+                {{d-button class="btn-default" icon="upload" action=(action "createInviteCsv") label="user.invited.bulk_invite.text"}}
+              {{/unless}}
+            {{/if}}
           {{/if}}
           {{#if showBulkActionButtons}}
             {{#if inviteExpired}}

app/controllers/invites_controller.rb

@@ -361,6 +361,12 @@ class InvitesController < ApplicationController
   def resend_all_invites
     guardian.ensure_can_resend_all_invites!(current_user)
 
+    begin
+      RateLimiter.new(current_user, "bulk-reinvite-per-day", 1, 1.day, apply_limit_to_staff: true).performed!
+    rescue RateLimiter::LimitExceeded
+      return render_json_error(I18n.t("rate_limiter.slow_down"))
+    end
+
     Invite.pending(current_user)
       .where('invites.email IS NOT NULL')
       .find_each { |invite| invite.resend_invite }

config/locales/server.en.yml

@@ -1465,6 +1465,7 @@ en:
     watched_word_regexp_error: "The regular expression for '%{action}' watched words is invalid. Please check your <a href='%{base_path}/admin/customize/watched_words'>Watched Word settings</a>, or disable the 'watched words regular expressions' site setting."
 
   site_settings:
+    allow_bulk_invite: "Allow bulk invites by uploading a CSV file"
     disabled: "disabled"
     display_local_time_in_user_card: "Display the local time based on a user's timezone when their user card is opened."
     censored_words: "Words that will be automatically replaced with &#9632;&#9632;&#9632;&#9632;"

config/site_settings.yml

@@ -584,7 +584,7 @@ users:
     client: true
     default: true
   invite_expiry_days:
-    default: 30
+    default: 90
     client: true
     max: 36500
   invites_per_page:
@@ -2347,6 +2347,10 @@ uncategorized:
     default: false
     hidden: true
 
+  allow_bulk_invite:
+    default: true
+    client: true
+
   max_bulk_invites:
     default: 50000
     hidden: true

lib/rate_limiter.rb

@@ -37,7 +37,7 @@ class RateLimiter
     "#{RateLimiter.key_prefix}:#{@user && @user.id}:#{type}"
   end
 
-  def initialize(user, type, max, secs, global: false, aggressive: false, error_code: nil)
+  def initialize(user, type, max, secs, global: false, aggressive: false, error_code: nil, apply_limit_to_staff: false, staff_limit: { max: nil, secs: nil })
     @user = user
     @type = type
     @key = build_key(type)
@@ -46,6 +46,14 @@ class RateLimiter
     @global = global
     @aggressive = aggressive
     @error_code = error_code
+    @apply_limit_to_staff = apply_limit_to_staff
+    @staff_limit = staff_limit
+
+    # override the default values if staff user, and staff specific max is passed
+    if @user&.staff? && !@apply_limit_to_staff && @staff_limit[:max].present?
+      @max = @staff_limit[:max]
+      @secs = @staff_limit[:secs]
+    end
   end
 
   def clear!
@@ -115,8 +123,7 @@ class RateLimiter
   def performed!(raise_error: true)
     return true if rate_unlimited?
     now = Time.now.to_i
-
-    if ((max || 0) <= 0) || rate_limiter_allowed?(now)
+    if ((@max || 0) <= 0) || rate_limiter_allowed?(now)
       raise RateLimiter::LimitExceeded.new(seconds_to_wait(now), @type, @error_code) if raise_error
       false
     else
@@ -153,7 +160,6 @@ class RateLimiter
   private
 
   def rate_limiter_allowed?(now)
-
     lua, lua_sha = nil
     if @aggressive
       lua = PERFORM_LUA_AGGRESSIVE
@@ -193,7 +199,7 @@ class RateLimiter
   end
 
   def rate_unlimited?
-    !!(RateLimiter.disabled? || (@user && @user.staff?))
+    !!(RateLimiter.disabled? || (@user&.staff? && !@apply_limit_to_staff && @staff_limit[:max].nil?))
   end
 
   def eval_lua(lua, sha, keys, args)

spec/components/rate_limiter_spec.rb

@@ -6,7 +6,11 @@ require 'rate_limiter'
 describe RateLimiter do
 
   fab!(:user) { Fabricate(:user) }
+  fab!(:admin) { Fabricate(:admin) }
   let(:rate_limiter) { RateLimiter.new(user, "peppermint-butler", 2, 60) }
+  let(:apply_staff_rate_limiter) { RateLimiter.new(admin, "peppermint-servant", 5, 40, apply_limit_to_staff: true) }
+  let(:staff_rate_limiter) { RateLimiter.new(user, "peppermind-servant", 5, 40, staff_limit: { max: 10, secs: 80 }) }
+  let(:admin_staff_rate_limiter) { RateLimiter.new(admin, "peppermind-servant", 5, 40, staff_limit: { max: 10, secs: 80 }) }
 
   context 'disabled' do
     before do
@@ -32,6 +36,8 @@ describe RateLimiter do
     before do
       RateLimiter.enable
       rate_limiter.clear!
+      staff_rate_limiter.clear!
+      admin_staff_rate_limiter.clear!
     end
 
     context 'aggressive rate limiter' do
@@ -46,7 +52,6 @@ describe RateLimiter do
 
         limiter.performed!
         limiter.performed!
-
         freeze_time 29.seconds.from_now
 
         expect do
@@ -189,6 +194,34 @@ describe RateLimiter do
           user.moderator = true
           expect { rate_limiter.performed! }.not_to raise_error
         end
+
+        it "applies max / secs to staff when apply_limit_to_staff flag is true" do
+          5.times { apply_staff_rate_limiter.performed! }
+          freeze_time 10.seconds.from_now
+          expect { apply_staff_rate_limiter.performed! }.to raise_error do |error|
+            expect(error).to be_a(RateLimiter::LimitExceeded)
+            expect(error).to having_attributes(available_in: 30)
+          end
+        end
+
+        it "applies staff_limit max when present for staff" do
+          expect(admin_staff_rate_limiter.can_perform?).to eq(true)
+          expect(admin_staff_rate_limiter.remaining).to eq(10)
+        end
+
+        it "applies staff_limit secs when present for staff" do
+          10.times { admin_staff_rate_limiter.performed! }
+          freeze_time 10.seconds.from_now
+          expect { admin_staff_rate_limiter.performed! }.to raise_error do |error|
+            expect(error).to be_a(RateLimiter::LimitExceeded)
+            expect(error).to having_attributes(available_in: 70)
+          end
+        end
+
+        it "applies standard max to non-staff users when staff_limit values are present" do
+          expect(staff_rate_limiter.can_perform?).to eq(true)
+          expect(staff_rate_limiter.remaining).to eq(5)
+        end
       end
 
       context "rollback!" do

spec/requests/invites_controller_spec.rb

@@ -907,15 +907,15 @@ describe InvitesController do
 
       freeze_time
 
-      user = Fabricate(:admin)
-      new_invite = Fabricate(:invite, invited_by: user)
-      expired_invite = Fabricate(:invite, invited_by: user)
+      admin = Fabricate(:admin)
+      new_invite = Fabricate(:invite, invited_by: admin)
+      expired_invite = Fabricate(:invite, invited_by: admin)
       expired_invite.update!(expires_at: 2.days.ago)
-      redeemed_invite = Fabricate(:invite, invited_by: user)
+      redeemed_invite = Fabricate(:invite, invited_by: admin)
       Fabricate(:invited_user, invite: redeemed_invite, user: Fabricate(:user))
       redeemed_invite.update!(expires_at: 5.days.ago)
 
-      sign_in(user)
+      sign_in(admin)
       post '/invites/reinvite-all'
 
       expect(response.status).to eq(200)
@@ -953,6 +953,15 @@ describe InvitesController do
         expect(Jobs::BulkInvite.jobs.size).to eq(1)
       end
 
+      it 'limits admins when bulk inviting' do
+        sign_in(admin)
+        post '/invites/upload_csv.json', params: { file: file, name: 'discourse.csv' }
+        expect(response.status).to eq(200)
+        post '/invites/upload_csv.json', params: { file: file, name: 'discourse.csv' }
+        expect(response.status).to eq(422)
+        expect(Jobs::BulkInvite.jobs.size).to eq(1)
+      end
+
       it 'allows admin to bulk invite when DiscourseConnect enabled' do
         SiteSetting.discourse_connect_url = "https://example.com"
         SiteSetting.enable_discourse_connect = true