Merge branch 'zj-feature-flag' into 'master'

Add Acceptance testing issue template

See merge request gitlab-org/gitlab-ce!21156

.gitlab/issue_templates/Acceptance_Testing.md

+## Details
+- **Feature Toggle Name**: `FEATURE_NAME`
+- **Required GitLab Version**: `vX.X`
+
+--------------------------------------------------------------------------------
+
+## 1. Preparation
+
+- [ ] **Controllers and workers**:
+  1. Please link to dashboards of the workers, and the controllers and actions that can be impacted
+  2. ...
+  3. ...
+
+## 2. Development Trial
+
+#### Check Dev Server Versions
+- [ ] GitLab: https://dev.gitlab.org/help
+
+#### Enable on `dev.gitlab.org`:
+- [ ] `/chatops feature set FEATURE_NAME true --dev` in [`#dev-gitlab`](https://gitlab.slack.com/messages/C6WQ87MU3)
+
+Then leave running while monitoring and performing some testing through web, api or SSH.
+
+#### Monitor
+
+- [ ] [Monitor Using Grafana](https://dashboards.gitlab.net)
+- [ ] [Inspect logs in ELK](https://log.gitlab.net/app/kibana)
+- [ ] [Check for errors in GitLab Dev Sentry](https://sentry.gitlap.com/gitlab/devgitlaborg/?query=is%3Aunresolved)
+
+## 2. Staging Trial
+
+#### Check Staging Server Versions
+- [ ] GitLab: https://staging.gitlab.com/help
+
+#### Enable on `staging.gitlab.com`
+- [ ] `/chatops run feature set FEATURE_NAME true --staging` in [`#development`](https://gitlab.slack.com/messages/C02PF508L/)
+
+Then leave running while monitoring for at least **15 minutes** while performing some testing through web, api or SSH.
+
+#### Monitor
+
+- [ ] [Monitor Using Grafana](https://dashboards.gitlab.net)
+- [ ] [Inspect logs in ELK](https://log.gitlab.net/app/kibana)
+- [ ] [Check for errors in GitLab Sentry](https://sentry.gitlap.com/gitlab/gitlabcom/?query=is%3Aunresolved)
+
+## 4. Production Server Version Check
+
+- [ ] GitLab: https://gitlab.com/help
+
+## 5. Initial Impact Check
+
+- [ ] Enable for a subset of users, when using percentage gates: 1%.
+
+Then leave running while monitoring for at least **15 minutes** while performing some testing through web, api or SSH.
+
+#### Monitor
+
+- [ ] [Monitor Using Grafana](https://dashboards.gitlab.net)
+- [ ] [Inspect logs in ELK](https://log.gitlab.net/app/kibana)
+- [ ] [Check for errors in GitLab Sentry](https://sentry.gitlap.com/gitlab/gitlabcom/?query=is%3Aunresolved)
+
+## 6. Low Impact Check
+
+- [ ] Enable for a bigger subset of users, when using percentage gates: 10%.
+
+Then leave running while monitoring for at least **30 minutes** while performing some testing through web, api or SSH.
+
+#### Monitor
+
+- [ ] [Monitor Using Grafana](https://dashboards.gitlab.net)
+- [ ] [Inspect logs in ELK](https://log.gitlab.net/app/kibana)
+- [ ] [Check for errors in GitLab Sentry](https://sentry.gitlap.com/gitlab/gitlabcom/?query=is%3Aunresolved)
+
+## 7. Mid Impact Trial
+
+- [ ] Enable for a big subset of users, when using percentage gates: 50%.
+
+Then leave running while monitoring for at least **12 hours** while performing some testing through web, api or SSH.
+
+#### Monitor
+
+- [ ] [Monitor Using Grafana](https://dashboards.gitlab.net)
+- [ ] [Inspect logs in ELK](https://log.gitlab.net/app/kibana)
+- [ ] [Check for errors in GitLab Sentry](https://sentry.gitlap.com/gitlab/gitlabcom/?query=is%3Aunresolved)
+
+## 8. Full Impact Trial
+
+- [ ] Enable for all users: `/chatops run feature set FEATURE_NAME true
+
+Then leave running while monitoring for at least **1 week**.
+
+#### Monitor
+
+- [ ] [Monitor Using Grafana](https://dashboards.gitlab.net)
+- [ ] [Inspect logs in ELK](https://log.gitlab.net/app/kibana)
+- [ ] [Check for errors in GitLab Dev Sentry](https://sentry.gitlap.com/gitlab/devgitlaborg/?query=is%3Aunresolved)
+
+#### Success?
+
+- [ ] Remove the feature gate from the code, and close this issue with that MR.

app/models/namespace.rb

@@ -10,6 +10,7 @@ class Namespace < ActiveRecord::Base
   include Storage::LegacyNamespace
   include Gitlab::SQL::Pattern
   include IgnorableColumn
+  include FeatureGate
 
   ignore_column :deleted_at
 
@@ -124,7 +125,6 @@ class Namespace < ActiveRecord::Base
   def to_param
     full_path
   end
-  alias_method :flipper_id, :to_param
 
   def human_name
     owner_name

doc/development/feature_flags.md

@@ -20,7 +20,40 @@ dynamic (querying the DB etc.).
 Once defined in `lib/feature.rb`, you will be able to activate a
 feature for a given feature group via the [`feature_group` param of the features API](../api/features.md#set-or-create-a-feature)
 
+For GitLab.com, team members have access to feature flags through chatops. Only
+percentage gates are supported at this time. Setting a feature to be used 50% of
+the time, you should execute `/chatops run feature set my_feature_flag 50`.
+
 ## Feature flags for user applications
 
 GitLab does not yet support the use of feature flags in deployed user applications.
 You can follow the progress on that [in the issue on our issue tracker](https://gitlab.com/gitlab-org/gitlab-ee/issues/779).
+
+## Developing with feature flags
+
+In general, it's better to have a group- or user-based gate, and you should prefer
+it over the use of percentage gates. This would make debugging easier, as you
+filter for example logs and errors based on actors too. Futhermore, this allows
+for enabling for the `gitlab-org` group first, while the rest of the users
+aren't impacted.
+
+```ruby
+# Good
+Feature.enabled?(:feature_flag, project)
+
+# Avoid, if possible
+Feature.enabled?(:feature_flag)
+```
+
+To use feature gates based on actors, the model needs to respond to
+`flipper_id`. For example, to enable for the Foo model:
+
+```ruby
+class Foo < ActiveRecord::Base
+  include FeatureGate
+end
+```
+
+Features that are developed and are intended to be merged behind a feature flag
+should not include a changelog entry. The entry should be added in the merge
+request removing the feature flags.