work in progress, admin page for upgrades (provides source lives in git)

app/controllers/admin/upgrade_controller.rb

@@ -0,0 +1,20 @@
+# EXPERIMENTAL: front end for upgrading your instance using the web UI
+
+class Admin::UpgradeController < Admin::AdminController
+
+  before_filter :ensure_admin
+  skip_before_filter :check_xhr
+
+  layout 'no_js'
+
+  def index
+    require_dependency 'upgrade/git_repo'
+    @main_repo = Upgrade::GitRepo.new(Rails.root)
+  end
+
+  protected
+
+  def ensure_admin
+    raise Discourse::InvalidAccess.new unless current_user.admin?
+  end
+end

app/views/admin/upgrade/_git_status.html.erb

@@ -0,0 +1,10 @@
+<% if repo.valid? %>
+  Current version: <%= repo.latest_local_commit %> (<%= time_ago_in_words repo.latest_local_commit_date %> ago),
+  Remote version: <a href="<%= repo.url %>"><%= repo.latest_origin_commit %></a> (<%= time_ago_in_words repo.latest_origin_commit_date %> ago)
+  <% if repo.commits_behind > 0 %>
+    commits behind: <%= repo.commits_behind %>
+    <button action="">upgrade</button>
+  <% end %>
+<% else %>
+    Not under source control.
+<% end %>

app/views/admin/upgrade/index.html.erb

@@ -0,0 +1,18 @@
+<h2>Discourse</h2>
+<p>
+<%= render partial: 'git_status', locals: {repo: @main_repo} %>
+</p>
+
+<h2>Plugins</h2>
+<ul>
+  <% Discourse.plugins.each do |plugin| %>
+    <li>
+      <%= plugin.name %> -
+      <%= render partial: 'git_status', locals: {repo: Upgrade::GitRepo.new(File.dirname(plugin.path))} %>
+    </li>
+  <% end %>
+</ul>
+
+<h2>Processes</h2>
+
+<h2>Log</h2>

config/routes.rb

@@ -21,6 +21,7 @@ Discourse::Application.routes.draw do
   namespace :admin, constraints: StaffConstraint.new do
     get '' => 'admin#index'
 
+
     resources :site_settings, constraints: AdminConstraint.new
 
     get 'reports/:type' => 'reports#show'
@@ -96,7 +97,10 @@ Discourse::Application.routes.draw do
         delete 'key' => 'api#revoke_key'
       end
     end
-  end
+
+    get 'upgrade' => 'upgrade#index'
+
+  end # admin namespace
 
   get 'email_preferences' => 'email#preferences_redirect', :as => 'email_preferences_redirect'
   get 'email/unsubscribe/:key' => 'email#unsubscribe', as: 'email_unsubscribe'

lib/upgrade/git_repo.rb

@@ -0,0 +1,69 @@
+module Upgrade; end
+
+# like Grit just very very minimal
+class Upgrade::GitRepo
+  attr_reader :path
+
+  def initialize(path)
+    @path = path
+    @memoize = {}
+  end
+
+  def valid?
+    File.directory?("#{path}/.git")
+  end
+
+  def latest_local_commit
+    run "rev-parse --short HEAD"
+  end
+
+  def latest_origin_commit
+    run "rev-parse --short #{tracking_branch}"
+  end
+
+  def latest_origin_commit_date
+    commit_date(latest_origin_commit)
+  end
+
+  def latest_local_commit_date
+    commit_date(latest_local_commit)
+  end
+
+  def commits_behind
+    run("rev-list --count #{tracking_branch}..HEAD").to_i
+  end
+
+  def url
+    url = run "config --get remote.origin.url"
+    if url =~ /^git/
+      # hack so it works with git urls
+      url = "https://github.com/#{url.split(":")[1]}"
+    end
+  end
+
+  protected
+
+  def commit_date(commit)
+    unix_timestamp = run('show -s --format="%ct" ' << commit).to_i
+    Time.at(unix_timestamp).to_datetime
+  end
+
+  def tracking_branch
+    run "for-each-ref --format='%(upstream:short)' $(git symbolic-ref -q HEAD)"
+  end
+
+  def ensure_updated
+    @updated ||= Thread.new do
+                   # this is a very slow operation, make it async
+                   `cd #{path} && git remote update`
+                 end
+  end
+
+  def run(cmd)
+    ensure_updated
+    @memoize[cmd] ||= `cd #{path} && git #{cmd}`.strip
+  rescue => e
+    p e
+  end
+
+end