Prometheus integration

Introduced in GitLab 9.0.

GitLab offers powerful integration with Prometheus for monitoring key metrics of your apps, directly within GitLab. Metrics for each environment are retrieved from Prometheus, and then displayed within the GitLab interface.

Environment Dashboard

There are two ways to set up Prometheus integration, depending on where your apps are running: * For deployments on Kubernetes, GitLab can automatically deploy and manage Prometheus * For other deployment targets, simply specify the Prometheus server.

Once enabled, GitLab will automatically detect metrics from known services in the metric library. You are also able to add your own metrics as well.

Enabling Prometheus Integration

Managed Prometheus on Kubernetes

Note: Introduced in GitLab 10.5

GitLab can seamlessly deploy and manage Prometheus on a connected Kubernetes cluster, making monitoring of your apps easy.

Requirements

Getting started

Once you have a connected Kubernetes cluster with Helm installed, deploying a managed Prometheus is as easy as a single click.

  1. Go to the Operations > Kubernetes page, to view your connected clusters
  2. Select the cluster you would like to deploy Prometheus to
  3. Click the Install button to deploy Prometheus to the cluster

Managed Prometheus Deploy

About managed Prometheus deployments

Prometheus is deployed into the gitlab-managed-apps namespace, using the official Helm chart. Prometheus is only accessible within the cluster, with GitLab communicating through the Kubernetes API.

The Prometheus server will automatically detect and monitor nodes, pods, and endpoints. To configure a resource to be monitored by Prometheus, simply set the following Kubernetes annotations: * prometheus.io/scrape to true to enable monitoring of the resource. * prometheus.io/port to define the port of the metrics endpoint. * prometheus.io/path to define the path of the metrics endpoint. Defaults to /metrics.

CPU and Memory consumption is monitored, but requires naming conventions in order to determine the environment. If you are using Auto DevOps, this is handled automatically.

The NGINX Ingress that is deployed by GitLab to clusters, is automatically annotated for monitoring providing key response metrics: latency, throughput, and error rates.

Manual configuration of Prometheus

Requirements

Integration with Prometheus requires the following:

  1. GitLab 9.0 or higher
  2. Prometheus must be configured to collect one of the supported metrics
  3. Each metric must be have a label to indicate the environment
  4. GitLab must have network connectivity to the Prometheus server

Getting started

Installing and configuring Prometheus to monitor applications is fairly straight forward.

  1. Install Prometheus
  2. Set up one of the supported monitoring targets
  3. Configure the Prometheus server to collect their metrics

Configuration in GitLab

The actual configuration of Prometheus integration within GitLab is very simple. All you will need is the DNS or IP address of the Prometheus server you’d like to integrate with.

  1. Navigate to the Integrations page
  2. Click the Prometheus service
  3. Provide the base URL of the your server, for example http://prometheus.example.com/. The Test Settings button can be used to confirm connectivity from GitLab to the Prometheus server.

Configure Prometheus Service

Monitoring CI/CD Environments

Once configured, GitLab will attempt to retrieve performance metrics for any environment which has had a successful deployment.

GitLab will automatically scan the Prometheus server for metrics from known serves like Kubernetes and NGINX, and attempt to identify individual environment. The supported metrics and scan process is detailed in our Prometheus Metric Library documentation.

You can view the performance dashboard for an environment by clicking on the monitoring button.

Adding additional metrics

Introduced in GitLab Premium 10.6.

Additional metrics can be monitored by adding them on the Prometheus integration page. Once saved, they will be displayed on the environment performance dashboard.

Add New Metric

A few fields are required: * Name: Chart title * Type: Type of metric. Metrics of the same type will be shown together. * Query: Valid PromQL query. Note, no validation is performed at this time. If the query is not valid, the dashboard will display an error. * Y-axis label: Y axis title to display on the dashboard. * Unit label: Query units, for example req / sec. Shown next to the value.

Query Variables

GitLab supports a limited set of CI variables in the Prometheus query. This is particularly useful for identifying a specific environment, for example with CI_ENVIRONMENT_SLUG. The supported variables are:

  • CI_ENVIRONMENT_SLUG
  • KUBE_NAMESPACE

To specify a variable in a query, enclose it in curly braces with a leading percent. For example: %{ci_environment_slug}.

Setting up alerts for Prometheus metrics

Introduced in GitLab Ultimate 11.2 for custom metrics, and 11.3 for library metrics.

Alerts can be configured for metricss directly in the performance dashboard.

To set an alert, click on the alarm icon in the top right corner of the metric you want to create the alert for. A dropdown will appear, with options to set the threshold and operator. Click Add to save and activate the alert.

Adding an alert

If the metric exceeds the threshold of the alert for over 5 minutes, an email will be sent to all Maintainers and Owners of the project.

To remove the alert, click back on the alert icon for the desired metric, and click Delete.

Determining the performance impact of a merge

Introduced in GitLab 9.2. GitLab 9.3 added the numeric comparison of the 30 minute averages. Requires Kubernetes metrics

Developers can view the performance impact of their changes within the merge request workflow. When a source branch has been deployed to an environment, a sparkline and numeric comparison of the average memory consumption will appear. On the sparkline, a dot indicates when the current changes were deployed, with up to 30 minutes of performance data displayed before and after. The comparison shows the difference between the 30 minute average before and after the deployment. This information is updated after each commit has been deployed.

Once merged and the target branch has been redeployed, the metrics will switch to show the new environments this revision has been deployed to.

Performance data will be available for the duration it is persisted on the Prometheus server.

Merge Request with Performance Impact

Troubleshooting

If the “No data found” screen continues to appear, it could be due to:

  • No successful deployments have occurred to this environment.
  • Prometheus does not have performance data for this environment, or the metrics are not labeled correctly. To test this, connect to the Prometheus server and run a query, replacing $CI_ENVIRONMENT_SLUG with the name of your environment.