When using FluxCD, ArgoCD or any other Git-based deployment strategy, automatic image updates really smooth out the release workflow. In my own personal opinion however, the automatic image update that FluxCD provides (and maybe Argo) seem a bit overkill for my own personal use cases.
After all, each image update requires a imagerepository resource continuously polling and a imagepolicy continuously applying. If I already know when my new release is created, why poll and apply it from the image-automation-controller within the cluster?
Keep It Simple, commit the new image tag directly from the release workflow
GitHub Workflow
Using only Git, Sed and Bash: I can automate applying the new image tag to the Kubernetes deployment manifest controlled by FluxCD.
I the following example: I grab the version tag from github.event.release.tag_name, checkout the flux repo fluxcd using a token named ‘FLUXCD_GITHUB_TOKEN’ that has permission to pull, commit and push.
The flux-update job can run directly after the image release job:
...
flux-update:
needs: [build]
runs-on: ubuntu-latest
env:
VERSIONTAG: ${{ github.event.release.tag_name }}
steps:
- name: Checkout flux repository
uses: actions/checkout@v4
with:
repository: username/fluxcd
token: ${{ secrets.FLUXCD_GITHUB_TOKEN }}
path: flux-repo
fetch-depth: 0
- name: Fetch repository content
run: |
cd flux-repo
git fetch origin
git checkout main
- name: Update Deployment image tag
run: |
DEPLOYMENT_FILE="flux-repo/apps/cluster/app/deployment.yaml"
OLD_IMAGE=$(grep "image:" "$DEPLOYMENT_FILE" | awk '{print $2}')
NEW_IMAGE="ghcr.io/username/app:$VERSIONTAG"
# Update the image tag
sed -i "s|image:.*|image: $NEW_IMAGE|" "$DEPLOYMENT_FILE"
# Create commit message
echo "Update image: $OLD_IMAGE -> $NEW_IMAGE" > commit_message.txt
- name: Commit and Push Flux Deployment Update
run: |
cd flux-repo
git config --local user.email "[email protected]"
git config --local user.name "GitHub Actions"
git add apps/cluster/app/deployment.yaml
git commit -F ../commit_message.txt
git push
Once the commit is pushed, FluxCD handles the rest as usual
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