Prometheus Gitlab Notifier

Tool which implements Alertmanager webhook notifier and creates Gitlab issue based on the the alert. It allows you to define own issue template using the Go template, labeling scheme of the resulting issue and group the alerts to a singe issue to avoid flooding yourself with identical issues.

This is probably possible in the Ultimate version of GitLab using the Prometheus integration, so if you have the possibility maybe first try that.

For new features or changes check out the CHANGELOG.md

How to run it

$ ./prometheus-gitlab-notifier --help
usage: prometheus-gitlab-notifier --gitlab.token.file=GITLAB.TOKEN.FILE --project.id=PROJECT.ID [<flags>]

Web server listening for webhooks of alertmanager and creating an issue in Gitlab based on it.

Flags:
  --help                         Show context-sensitive help (also try --help-long and --help-man).
  --debug                        Enables debug logging.
  --log.json                     Log in JSON format
  --server.addr="0.0.0.0:9629"   Allows to change the address and port at which the server will listen for incoming connections.
  --gitlab.url="https://gitlab.com"
                                 URL of the Gitlab API.
  --gitlab.token.file=GITLAB.TOKEN.FILE  
                                 Path to file containing gitlab token.
  --project.id=PROJECT.ID        Id of project where to create the issues.
  --group.interval=1h            Duration how long back to check for opened issues with the same group labels to append the new alerts to (go duration syntax allowing 'ns', 'us' , 'ms', 's', 'm', 'h').
  --issue.label=ISSUE.LABEL ...  Labels to add to the created issue. (Can be passed multiple times)
  --dynamic.issue.label.name=DYNAMIC.ISSUE.LABEL.NAME ...  
                                 Alert label, which is to be propagated to the resulting Gitlab issue as scoped label if present in the received alert. (Can be passed multiple times)
  --issue.template=ISSUE.TEMPLATE
                                 Path to the issue golang template file.
  --queue.size.limit=100         Limit of the alert queue size.
  --retry.backoff=5m             Duration how long to wait till next retry (go duration syntax allowing 'ns', 'us' , 'ms', 's', 'm', 'h').
  --retry.limit=5                Maximum number of retries for single alert. If exceeded it's thrown away.
  --graceful.shutdown.wait.duration=30s  
                                 Duration how long to wait on graceful shutdown marked as not ready (go duration syntax allowing 'ns', 'us' , 'ms', 's', 'm', 'h').

To test it is running check logs or http://0.0.0.0:9629/readiness

Try it out

You can send a test alert to it using the prepared alert JSON by running thin in root of this repo

curl -X POST -H "Content-Type: application/json" -d @./conf/alert.json http://localhost:9629/api/alertmanager

Issue template

Look of the resulting issue in Gitlab can be customized using Go template. Default template can be found in conf/default_issue.tmpl. The available data during templating is the Alertmanager webhook message struct itself. Example can be found in conf/alert.json. To use own template override the default one with the --issue.template flag.

The template is validated on startup but if even after validation the templating fails in the runtime, raw JSON of the alert will be pasted to the text of the issue as a fallback.

Example of the default template:

Configure Alertmanager

You just need to add the <webhook_config> receiver to your Alertmanager configuration and disable sending resolved notifications with send_resolved: false. Also better to set the repeat_interval to higher value.

See the minimal example in the conf/alertmanager_conf.yaml.

Issue labeling scheme

The Gitlab notifier allows to label the resulting issue based on the alert labels. It uses mostly Gitlab scoped labels in format label::value. The grouping labels of the alert are added to the issue automatically to allow identifying same alerts (more on that in Grouping section). Additionally, you can specify names of labels to be also added to the issue using flag --dynamic.issue.label.name. Last thing you can add are static labels which will be added to every issue using flag --issue.label,

Grouping

To avoid flooding gitlab with identical alerts if they happen to fire and resolve again and again, Gitlab notifier checks for issues witch the same grouping labels as the new incoming alert. If if it finds any still open issue younger than 1h by default (can be controlled by flag --group.interval), it only appends the rendered template to the end of the issue description and adds to the issue label appended-alerts::<number> witch count of how many times it was updated.

Deployment

Example kubernetes manifests can be found at kubernetes/

Instrumentation

• /liveness: liveness endpoint returns always 200
• /readiness: tries HEAD request to the configured Gitlab URL and fails if it does not succeeds.
• /metrics: metrics endpoint returning app runtime metrics in Prometheus format

How to contribute and release

Contributing:

1. Implement your changes and test them on your own testing repository.
2. Add note about changes made to the CHANGELOG.md Unreleased section.
3. Create PR and apply for CR from maintainers.
4. Get it merged.