Chainguard Image 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 Images are regularly-updated, minimal container images with low-to-zero CVEs.

Download this Image

This 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 behaviour 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/chainguard/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/chainguard/prometheus-alertmanager:latest

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

Contact Support

If you have a Zendesk account (typically set up for you by your Customer Success Manager) you can reach out to Chainguard's Customer Success team through our Zendesk portal.

What are Chainguard Images?

Chainguard Images are a collection of container images designed for security and minimalism.

Many Chainguard Images are distroless; they contain only an open-source application and its runtime dependencies. These images do not even contain a shell or package manager. Chainguard Images are built with Wolfi, our Linux undistro designed to produce container images that meet the requirements of a secure software supply chain.

The main features of Chainguard Images include:

• Minimal design, with no unnecessary software bloat
• Automated nightly builds to ensure Images are completely up-to-date and contain all available security patches
• High quality build-time SBOMs (software bills of materials) attesting the provenance of all artifacts within the Image
• Verifiable signatures provided by Sigstore
• Reproducible builds with Cosign and apko (read more about reproducibility)

-dev Variants

As mentioned previously, Chainguard’s distroless Images have no shell or package manager by default. This is great for security, but sometimes you need these things, especially in builder images. For those cases, most (but not all) Chainguard Images come paired with a -dev variant which does include a shell and package manager.

Although the -dev image variants have similar security features as their distroless versions, such as complete SBOMs and signatures, they feature additional software that is typically not necessary in production environments. The general recommendation is to use the -dev variants only to build the application and then copy all application artifacts into a distroless image, which will result in a final container image that has a minimal attack surface and won’t allow package installations or logins.

That being said, it’s worth noting that -dev variants of Chainguard Images are completely fine to run in production environments. After all, the -dev variants are still more secure than many popular container images based on fully-featured operating systems such as Debian and Ubuntu since they carry less software, follow a more frequent patch cadence, and offer attestations for what they include.

Learn More

To better understand how to work with Chainguard Images, we encourage you to visit Chainguard Academy, our documentation and education platform.