Merge branch '8-4-stable' into ci/api-triggers

* 8-4-stable: (280 commits)
  Add Changelog entry for build traces data integrity fix
  Update doc_styleguide.md [ci skip]
  Added hint that you can search users by name, username, or email.
  Add changelog
  Version 8.4.0.rc1
  Randomize metrics sample intervals
  Make the metrics sampler interval configurable
  Don't automatically require awesome_print
  Disable colorization if STDOUT is not a tty
  Block the reported user before destroying the record
  changes `$quote-gray` to `$secondary-text`
  makes message plural for multiple MRs and removes from loop. Duh.
  Prepare Installation and Update docs for 8.4 RC1
  Mention channel/key bug in irkerd docs
  Revert "Remove the `:coffee` and `:coffeescript` Haml filters"
  gets merge request discussion working again
  adds back in discussion.haml.html for issues commenting and closing/reopening properly.
  removing last chunk of MR ajax changes, rest will be in another MR
  reverting more MR ajax files, will appear in different commit
  reverting MR ajax changes, which will be in a different MR
  ...

1 files changed, 148 insertions, 0 deletions

diff --git a/doc/update/8.3-to-8.4.md b/doc/update/8.3-to-8.4.md
new file mode 100644
index 00000000000..1cbeab3eca3
--- /dev/null
+++ b/doc/update/8.3-to-8.4.md
@@ -0,0 +1,148 @@
+# From 8.3 to 8.4
+
+### 1. Stop server
+
+    sudo service gitlab stop
+
+### 2. Backup
+
+```bash
+cd /home/git/gitlab
+sudo -u git -H bundle exec rake gitlab:backup:create RAILS_ENV=production
+```
+
+### 3. Get latest code
+
+```bash
+sudo -u git -H git fetch --all
+sudo -u git -H git checkout -- db/schema.rb # local changes will be restored automatically
+```
+
+For GitLab Community Edition:
+
+```bash
+sudo -u git -H git checkout 8-4-stable
+```
+
+OR
+
+For GitLab Enterprise Edition:
+
+```bash
+sudo -u git -H git checkout 8-4-stable-ee
+```
+
+### 4. Update gitlab-shell
+
+```bash
+cd /home/git/gitlab-shell
+sudo -u git -H git fetch --all
+sudo -u git -H git checkout v2.6.9
+```
+
+### 5. Update gitlab-workhorse
+
+Install and compile gitlab-workhorse. This requires [Go 1.5](https://golang.org/dl)
+which should already be on your system from GitLab 8.1.
+
+```bash
+cd /home/git/gitlab-workhorse
+sudo -u git -H git fetch --all
+sudo -u git -H git checkout 0.5.4
+sudo -u git -H make
+```
+
+### 6. Install libs, migrations, etc.
+
+```bash
+cd /home/git/gitlab
+
+# MySQL installations (note: the line below states '--without postgres')
+sudo -u git -H bundle install --without postgres development test --deployment
+
+# PostgreSQL installations (note: the line below states '--without mysql')
+sudo -u git -H bundle install --without mysql development test --deployment
+
+# Run database migrations
+sudo -u git -H bundle exec rake db:migrate RAILS_ENV=production
+
+# Clean up assets and cache
+sudo -u git -H bundle exec rake assets:clean assets:precompile cache:clear RAILS_ENV=production
+
+```
+
+### 7. Update configuration files
+
+#### New configuration options for `gitlab.yml`
+
+There are new configuration options available for [`gitlab.yml`](config/gitlab.yml.example). View them with the command below and apply them manually to your current `gitlab.yml`:
+
+```sh
+git diff origin/8-3-stable:config/gitlab.yml.example origin/8-4-stable:config/gitlab.yml.example
+```
+
+#### Nginx configuration
+
+GitLab 8.3 introduced major changes in the NGINX configuration. Ensure you're
+still up-to-date with the latest changes:
+
+```sh
+# For HTTPS configurations
+git diff origin/8-3-stable:lib/support/nginx/gitlab-ssl origin/8-4-stable:lib/support/nginx/gitlab-ssl
+
+# For HTTP configurations
+git diff origin/8-3-stable:lib/support/nginx/gitlab origin/8-4-stable:lib/support/nginx/gitlab
+```
+
+If you are using Apache instead of NGINX please see the updated [Apache templates].
+Also note that because Apache does not support upstreams behind Unix sockets you
+will need to let gitlab-workhorse listen on a TCP port. You can do this
+via [/etc/default/gitlab].
+
+[Apache templates]: https://gitlab.com/gitlab-org/gitlab-recipes/tree/master/web-server/apache
+[/etc/default/gitlab]: https://gitlab.com/gitlab-org/gitlab-ce/blob/8-4-stable/lib/support/init.d/gitlab.default.example#L34
+
+#### Init script
+
+We updated the init script for GitLab in order to pass new
+configuration options to gitlab-workhorse. We let gitlab-workhorse
+connect to the Rails application via a Unix domain socket and we tell
+it where the 'public' directory of GitLab is.
+
+```
+cd /home/git/gitlab
+sudo cp lib/support/init.d/gitlab /etc/init.d/gitlab
+```
+
+### 8. Start application
+
+    sudo service gitlab start
+    sudo service nginx restart
+
+### 9. Check application status
+
+Check if GitLab and its environment are configured correctly:
+
+    sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production
+
+To make sure you didn't miss anything run a more thorough check:
+
+    sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production
+
+If all items are green, then congratulations, the upgrade is complete!
+
+## Things went south? Revert to previous version (8.3)
+
+### 1. Revert the code to the previous version
+
+Follow the [upgrade guide from 8.2 to 8.3](8.2-to-8.3.md), except for the
+database migration (the backup is already migrated to the previous version).
+
+### 2. Restore from the backup
+
+```bash
+cd /home/git/gitlab
+sudo -u git -H bundle exec rake gitlab:backup:restore RAILS_ENV=production
+```
+
+If you have more than one backup `*.tar` file(s) please add `BACKUP=timestamp_of_backup` to the command above.