Chainguard Container for prometheus-alertmanager

Minimalist Wolfi-based image for Prometheus Alertmanager. Handles alerts sent by client applications such as the Prometheus server. It takes care of deduplicating, grouping, and routing to the correct receiver.

Chainguard Containers are regularly-updated, secure-by-default container images.

Download this Container Image

For those with access, this container image is available on cgr.dev:

docker pull cgr.dev/ORGANIZATION/prometheus-alertmanager:latest

Be sure to replace the ORGANIZATION placeholder with the name used for your organization's private repository within the Chainguard Registry.

Usage

For full instructions on prometheus-alertmanager, refer to the official documentation. The GitHub repository can also be found here.

Default config settings

The upstream docker image, overrides some of the default values for alertmanager, for example, see here. We replicate the same behavior in the Chainguard image to provide parity with the upstream image.

Helm

To deploy via helm, please refer to the upstream helm charts documentation for comprehensive instructions, which includes supported parameters.

Below is an example of how to use the helm chart, overriding the image with the chainguard image:

helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update

helm install prom-alertmanager prometheus-community/alertmanager \
 --set image.repository=cgr.dev/ORGANIZATION/prometheus-alertmanager \
 --set image.tag=latest

The upstream helm chart provides some default config: values, but if you intend to deploy with additional configuration, i.e defining routes and receivers, you'll need to create your own custom values.yaml and pass this into the chart at deployment.

Docker

Create config file

Before running the container, you'll need to create a configuration file. This contains all the necessary configurations for Alertmanager, such as alerting routes, receivers, and integrations.

Refer to the official documentation for more information. Below is a simple example:

# Save this as 'alertmanager.yml')
global:
  resolve_timeout: 11m
  pagerduty_url: https://example-pagerduty.com/v2/test
route:
  group_by: ['alertname']
  group_wait: 10s
  group_interval: 10m
  repeat_interval: 1h
receivers:
  - name: 'example-webhook'
    webhook_configs:
    - url: 'http://example.com/hook'

In order to ensure the 'nonroot' container user can access the file when volume mounted (below step), ensure you've set read-only permissions:

chmod 400 alertmanager.ym

Run container

IMPORTANT: Prometheus looks for a file mounted as 'alertmanager.yml' (i.e not .yaml).

# TODO: Update '$(pwd)/alertmanager.yml' accordingly to reference your locally
# created config file.
docker run -p 9093:9093 \
  -v $(pwd)/alertmanager.yml:/etc/alertmanager/alertmanager.yml \
  --name alertmanager \
  cgr.dev/ORGANIZATION/prometheus-alertmanager:latest

Verify that Alertmanager is running correctly by accessing http://localhost:9093 on your browser.

What are Chainguard Containers?

Chainguard's free tier of Starter container images are built with Wolfi, our minimal Linux undistro.

All other Chainguard Containers are built with Chainguard OS, Chainguard's minimal Linux operating system designed to produce container images that meet the requirements of a more secure software supply chain.

The main features of Chainguard Containers include:

• Minimal design, without unnecessary software bloat
• Daily builds to ensure container images are up-to-date with available security patches
• High quality build-time SBOMs attesting to the provenance of all artifacts within the image
• Verifiable signatures provided by Sigstore
• Reproducible builds with Cosign and apko (read more about reproducibility)

For cases where you need container images with shells and package managers to build or debug, most Chainguard Containers come paired with a development, or -dev, variant.

In all other cases, including Chainguard Containers tagged as :latest or with a specific version number, the container images include only an open-source application and its runtime dependencies. These minimal container images typically do not contain a shell or package manager.

Although the -dev container image variants have similar security features as their more minimal versions, they include additional software that is typically not necessary in production environments. We recommend using multi-stage builds to copy artifacts from the -dev variant into a more minimal production image.

Need additional packages?

To improve security, Chainguard Containers include only essential dependencies. Need more packages? Chainguard customers can use Custom Assembly to add packages, either through the Console, chainctl, or API.

To use Custom Assembly in the Chainguard Console: navigate to the image you'd like to customize in your Organization's list of images, and click on the Customize image button at the top of the page.

Learn More

Refer to our Chainguard Containers documentation on Chainguard Academy. Chainguard also offers VMs and Libraries — contact us for access.

Trademarks

This software listing is packaged by Chainguard. The trademarks set forth in this offering are owned by their respective companies, and use of them does not imply any affiliation, sponsorship, or endorsement by such companies.