Continuous profiling support for the Container Registry

Context

Following a production request (gitlab-org/container-registry#31 (comment 379910324)) we've added continuous profiling support with Google Stackdriver to the Container Registry. Similar to Pages and Gitaly, this was done using LabKit's monitoring package.

This is an optional feature that can be enabled in the registry configuration settings.

We have not yet tagged a release with these changes. This should be synchronized with this issue.

Configuration

Please see the configuration docs.

Just like any other container registry settings, these can be defined either in the YAML configuration file or using the corresponding environment variable (path concatenated with _ and prefixed with REGISTRY_).

So for example, to enable the integration we need to set the monitoring.stackdriver.enabled setting in the configuration file or the REGISTRY_MONITORING_STACKDRIVER_ENABLED environment variable to true. This is false by default.

The remaining settings can be set in the same way. The GITLAB_CONTINUOUS_PROFILING environment variable (defined by LabKit) can be used instead.

Deployment

1. Rollout to Staging
2. Rollout to Canary
3. Rollout to Production