name: Flux GitOps Deploy
description: Update a Flux HelmRelease image tag in a GitOps repo to trigger a Kubernetes deployment
author: eric

inputs:
  image-repository:
    description: |
      Full image repository (e.g. git.ericxliu.me/eric/workout).
      Used to update 'repository:' fields in standard bjw-s app-template format.
      Optional when using tag-keys for non-standard layouts.
    required: false
    default: ""
  image-tag:
    description: Image tag to deploy (e.g. 2026-06-17-abc1234)
    required: true
  tag-keys:
    description: |
      Comma-separated YAML keys whose values should be set to image-tag.
      Defaults to 'tag' which matches the standard 'tag: <value>' format.
      For non-standard layouts, specify custom keys (e.g. 'rustImageTag,uiImageTag').
      Handles both unquoted values and quoted values with optional YAML anchors.
    required: false
    default: "tag"
  gitops-repo:
    description: SSH URL of the GitOps repo
    default: git@github.com:eric-x-liu/k8s-flux.git
    required: false
  gitops-file:
    description: Path to the release YAML in the GitOps repo (e.g. apps/myapp/workout/release.yaml)
    required: true
  deploy-key:
    description: SSH private key with push access to the GitOps repo
    required: true
  git-user-name:
    description: Git commit author name
    default: gitops-ci
    required: false
  git-user-email:
    description: Git commit author email
    default: gitops-ci@users.noreply.git.ericxliu.me
    required: false
  commit-message:
    description: "Custom commit message. Supports {app} and {tag} placeholders."
    default: ""
    required: false

runs:
  using: composite
  steps:
    - name: Update GitOps image tag
      shell: bash
      env:
        IMAGE_REPOSITORY: ${{ inputs.image-repository }}
        IMAGE_TAG: ${{ inputs.image-tag }}
        TAG_KEYS: ${{ inputs.tag-keys }}
        GITOPS_REPO: ${{ inputs.gitops-repo }}
        GITOPS_FILE: ${{ inputs.gitops-file }}
        DEPLOY_KEY: ${{ inputs.deploy-key }}
        GIT_USER_NAME: ${{ inputs.git-user-name }}
        GIT_USER_EMAIL: ${{ inputs.git-user-email }}
        COMMIT_MESSAGE: ${{ inputs.commit-message }}
      run: |
        set -euo pipefail

        # ── SSH setup ──────────────────────────────────────────────
        mkdir -p "$HOME/.ssh"
        printf '%s\n' "$DEPLOY_KEY" > "$HOME/.ssh/flux_deploy_key"
        chmod 600 "$HOME/.ssh/flux_deploy_key"
        ssh-keyscan -H github.com >> "$HOME/.ssh/known_hosts" 2>/dev/null
        export GIT_SSH_COMMAND="ssh -i $HOME/.ssh/flux_deploy_key -o IdentitiesOnly=yes -o StrictHostKeyChecking=yes"

        # ── Clone GitOps repo ──────────────────────────────────────
        workdir="$(mktemp -d)"
        git clone "$GITOPS_REPO" "$workdir/gitops"
        cd "$workdir/gitops"

        # ── Update image fields via regex ──────────────────────────
        python3 << 'PYEOF'
        import os, pathlib, re

        path      = pathlib.Path(os.environ["GITOPS_FILE"])
        repo      = os.environ.get("IMAGE_REPOSITORY", "")
        tag       = os.environ["IMAGE_TAG"]
        tag_keys  = [k.strip() for k in os.environ["TAG_KEYS"].split(",") if k.strip()]
        Q = '"'

        text = path.read_text()

        # Update repository field (only if image-repository is provided)
        if repo:
            text = re.sub(r"(repository:\s*)\S+", lambda m: m.group(1) + repo, text, count=1)

        # Update each tag key
        for key in tag_keys:
            # Pattern matches both formats:
            #   tag: 2026-06-17-abc1234           (unquoted)
            #   tag: "2026-06-17-abc1234"         (quoted)
            #   imageTag: &anchor "value"         (YAML anchor with quotes)
            #   tag: *anchor                      (YAML alias — left alone by design)
            pat_quoted = r"(" + re.escape(key) + r':\s*(?:&\S+\s+)?)"[^"]*"'
            quoted = re.sub(
                pat_quoted,
                lambda m: m.group(1) + Q + tag + Q,
                text
            )
            if quoted != text:
                text = quoted
            else:
                # Unquoted value (e.g., tag: 2026-06-17-abc1234)
                text = re.sub(
                    r"(" + re.escape(key) + r":\s*)\S+",
                    lambda m: m.group(1) + tag,
                    text,
                    count=1
                )

        path.write_text(text)
        PYEOF

        # ── Commit + push (idempotent) ────────────────────────────
        if git diff --quiet -- "$GITOPS_FILE"; then
          echo "✅ GitOps already points to ${IMAGE_REPOSITORY:-(custom keys)}:$IMAGE_TAG — nothing to do"
          exit 0
        fi

        # Derive app name from the gitops file path for the default commit message
        APP_NAME="$(basename "$(dirname "$GITOPS_FILE")")"

        if [ -z "$COMMIT_MESSAGE" ]; then
          COMMIT_MESSAGE="Update ${APP_NAME} image to ${IMAGE_TAG}"
        else
          COMMIT_MESSAGE="${COMMIT_MESSAGE//\{app\}/$APP_NAME}"
          COMMIT_MESSAGE="${COMMIT_MESSAGE//\{tag\}/$IMAGE_TAG}"
        fi

        git config user.name  "$GIT_USER_NAME"
        git config user.email "$GIT_USER_EMAIL"
        git add "$GITOPS_FILE"
        git commit -m "$COMMIT_MESSAGE"
        git push origin main

        echo "🚀 Pushed: ${APP_NAME} → $IMAGE_TAG"