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Application configuration

Most of the runtime configuration for Argo CD Image Updater is performed by setting various annotations on resources of type Application, which are managed by Argo CD.

For its annotations, Argo CD Image Updater uses the following prefix:

This section of the documentation tells you about which things you can configure, and what annotations are available.

Marking an application for being updateable

In order for Argo CD Image Updater to know which applications it should inspect for updating the workloads' container images, the corresponding Kubernetes resource needs to be correctly annotated. Argo CD Image Updater will inspect only resources of kind, that is, your Argo CD Application resources. Annotations on other kinds of resources will have no effect and will not be considered.

As explained earlier, your Argo CD applications must be of either Kustomize or Helm type. Other types of applications will be ignored.

So, in order for Argo CD Image Updater to consider your application for the update of its images, at least the following criteria must be met:

  • Your Application resource is annotated with the mandatory annotation of, which contains at least one valid image specification (see Images Configuration).

  • Your Application resource is of type Helm or Kustomize

An example of a correctly annotated Application resources might look like:

kind: Application
  name: guestbook
  namespace: argocd
    namespace: guestbook
    server: https://kubernetes.default.svc
  project: default
    path: helm-guestbook
    targetRevision: HEAD

There is a whole chapter dedicated on how to configure images for update.

Configuring the write-back method

The Argo CD Image Updater supports two distinct methods on how to update images of an application:

  • imperative, via Argo CD API
  • declarative, by pushing changes to a Git repository

Depending on your setup and requirements, you can chose the write-back method per Application, but not per image. As a rule of thumb, if you are managing Application in Git (i.e. in an app-of-apps setup), you most likely want to chose the Git write-back method.

The write-back method is configured via an annotation on the Application resource: <method>

Where <method> must be one of argocd (imperative) or git (declarative).

The default used by Argo CD Image Updater is argocd.

You can read more about the update methods and how to configure them in the chapter about update methods

Application defaults

Additional to per-image configuration, you can also set some defaults for the application.

For example, if you have multiple images tracked in your application, and all of them should use the latest update strategy, you can define this strategy as the application's default and may omit any specific configuration for the images' update strategy.