Skip to content

Argo CD Image Updater

A tool to automatically update the container images of Kubernetes workloads that are managed by Argo CD.

A note on the current status

Argo CD Image Updater is under active development.

You are welcome to test it out on non-critical environments, and of course to contribute by many means.

There will be (probably a lot of) breaking changes from release to release as development progresses until version 1.0. We will do our best to indicate any breaking change and how to un-break it in the respective release notes

Overview

The Argo CD Image Updater can check for new versions of the container images that are deployed with your Kubernetes workloads and automatically update them to their latest allowed version using Argo CD. It works by setting appropriate application parameters for Argo CD applications, i.e. similar to argocd app set --helm-set image.tag=v1.0.1 - but in a fully automated manner.

Usage is simple: You annotate your Argo CD Application resources with a list of images to be considered for update, along with a version constraint to restrict the maximum allowed new version for each image. Argo CD Image Updater then regularly polls the configured applications from Argo CD and queries the corresponding container registry for possible new versions. If a new version of the image is found in the registry, and the version constraint is met, Argo CD Image Updater instructs Argo CD to update the application with the new image.

Depending on your Automatic Sync Policy for the Application, Argo CD will either automatically deploy the new image version or mark the Application as Out Of Sync, and you can trigger the image update manually by syncing the Application. Due to the tight integration with Argo CD, advanced features like Sync Windows, RBAC authorization on Application resources etc. are fully supported.

Features

  • Updates images of apps that are managed by Argo CD and are either generated from Helm or Kustomize tooling
  • Update app images according to different update strategies
    • semver: update to highest allowed version according to given image constraint,
    • latest: update to the most recently created image tag,
    • name: update to the last tag in an alphabetically sorted list
    • digest: update to the most recent pushed version of a mutable tag
  • Support for widely used container registries
  • Support for private container registries via configuration
  • Can write changes back to Git
  • Ability to filter list of tags returned by a registry using matcher functions
  • Support for custom, per-image pull secrets (using generic K8s secrets, K8s pull secrets, environment variables or external scripts)
  • Runs in a Kubernetes cluster or can be used stand-alone from the command line
  • Ability to perform parallel update of applications

Limitations

The two most important limitations first. These will most likely not change anywhere in the near future, because they are limitations by design.

Please make sure to understand these limitations, and do not send enhancement requests or bug reports related to the following:

  • The applications you want container images to be updated must be managed using Argo CD. There is no support for workloads not managed using Argo CD.

  • Argo CD Image Updater can only update container images for applications whose manifests are rendered using either Kustomize or Helm and - especially in the case of Helm - the templates need to support specifying the image's tag (and possibly name) using a parameter (i.e. image.tag).

Otherwise, current known limitations are:

  • Image pull secrets must exist in the same Kubernetes cluster where Argo CD Image Updater is running in (or has access to). It is currently not possible to fetch those secrets from other clusters.

Questions, help and support

If you have any questions, need some help in setting things up or just want to discuss something, feel free to

  • open an issue on our GitHub issue tracker or

  • join us in the #argo-cd-image-updater channel on the CNCF slack