Summary

Tag tracking allows us to set a target revision for a git repo or Helm chart as a range (eg 1.*). It would be useful if there were a build environment variable which contains the tag/revision which the target revision range resolved to, for example 1.2.3.

None of the existing build environment variables do this. ARGOCD_APP_SOURCE_TARGET_REVISION will be set to 1.* (in this example), and ARGOCD_APP_REVISION will be set to the commit hash (eg f913b6cbf58aa5ae5ca1f8a2b149477aebcbd9d8).

Motivation

Consider a git repo containing service code and a Helm chart, and an accompanying CI build process which builds a docker image from the service code. When tagging the repo with a release tag (eg 1.2.3) the image gets built with a tag matching the release tag.

In this case when setting a target revision like 1.* we would also need to set/override a Helm value for the image tag too. It would be useful to be able to do this with a build variable, for example:

source:
  targetRevision: 1.*
  helm:
    parameters:
      - name: imageTag
        value: "$<some build var that will resolve to 1.2.3>"

Proposal

Adding a new build environment variable called ARGOCD_APP_SOURCE_TARGET_REVISION_RESOLVED or similar, which will be set to the resolved SemVer value. If the target revision is not a SemVer range then ARGOCD_APP_SOURCE_TARGET_REVISION_RESOLVED can be set to the target revision (ie the same as ARGOCD_APP_SOURCE_TARGET_REVISION.