feat: harmont GitHub Action with Docker image caching (#2)

Author: markovejnovic

.github/workflows/test-action.yml

@@ -83,3 +83,53 @@ jobs:
         run: |
           echo "Cache hit: ${{ steps.setup.outputs.cache-hit }}"
           hm --version
+
+  custom-binary:
+    name: Custom hm-path (dogfood pattern)
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Create mock hm binary
+        run: |
+          mkdir -p /tmp/mock-hm
+          cat > /tmp/mock-hm/hm << 'SCRIPT'
+          #!/bin/bash
+          case "$1" in
+            --version) echo "mock-0.0.1" ;;
+            cache)
+              case "$2" in
+                save)
+                  mkdir -p "$3"
+                  echo '{"images":{}}' > "$3/manifest.json"
+                  echo "abc123"
+                  ;;
+                restore) echo "restored" ;;
+              esac
+              ;;
+            run) echo "ran pipeline: $2" ;;
+          esac
+          SCRIPT
+          chmod +x /tmp/mock-hm/hm
+
+      - name: Cache restore (no manifest yet, cold start)
+        uses: ./cache-restore
+        with:
+          working-directory: tests/fixtures
+
+      - name: Run with custom binary
+        working-directory: tests/fixtures
+        env:
+          HM_NONINTERACTIVE: '1'
+        run: /tmp/mock-hm/hm run hello
+
+      - name: Cache save with custom binary
+        if: always()
+        uses: ./cache-save
+        with:
+          working-directory: tests/fixtures
+          hm-path: /tmp/mock-hm/hm

README.md

@@ -1,29 +1,17 @@
 # actions-hm
 
-[![CI](https://img.shields.io/github/actions/workflow/status/harmont-dev/actions-hm/ci.yml?branch=main&logo=github&label=CI)](https://github.com/harmont-dev/actions-hm/actions)
-[![GitHub release](https://img.shields.io/github/v/release/harmont-dev/actions-hm?logo=github)](https://github.com/harmont-dev/actions-hm/releases)
-[![Marketplace](https://img.shields.io/badge/marketplace-harmont-purple?logo=github)](https://github.com/marketplace/actions/harmont)
+> [!WARNING]
+>
+> This repo is currently considered experimental.
 
-Run [harmont](https://harmont.dev) pipelines in GitHub Actions. One step. Automatic Docker image caching via your container registry.
+Run [harmont](https://harmont.dev) pipelines in GitHub Actions.
 
 ```yaml
-- uses: harmont-dev/actions-hm@v1
+- uses: harmont-dev/actions-hm@main
   with:
     pipeline: ci
 ```
 
-That's it. This installs `hm`, pulls cached Docker images from GHCR, runs your pipeline, and pushes updated images back — with automatic cleanup of stale cache entries.
-
-## Why
-
-You already define your CI with harmont. This action lets you run it on GitHub Actions without boilerplate:
-
-- **Zero config caching** — Docker images cached in GHCR with native layer deduplication
-- **One step** — no separate setup, login, cache-restore, cache-save dance
-- **Fast repeat runs** — `hm` binary cached between runs, images pulled only when changed
-- **Auto cleanup** — stale registry images pruned automatically (configurable retention)
-- **Granular control** — use sub-actions individually when you need custom steps between them
-
 ## Usage
 
 ### Minimal (all-in-one)
@@ -55,15 +43,15 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: harmont-dev/actions-hm@v1
+      - uses: harmont-dev/actions-hm@main
         with:
           pipeline: lint
 
   test:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: harmont-dev/actions-hm@v1
+      - uses: harmont-dev/actions-hm@main
         with:
           pipeline: test
           parallelism: 4
@@ -95,14 +83,6 @@ jobs:
         if: always()
 ```
 
-### Pin to specific version
-
-```yaml
-- uses: harmont-dev/actions-hm@v1
-  with:
-    version: 0.5.0
-```
-
 ## Inputs
 
 | Input | Default | Description |
@@ -116,6 +96,7 @@ jobs:
 | `cache-registry-prefix` | *(auto)* | Registry path prefix. Default: `ghcr.io/<owner>/<repo>/harmont-cache` |
 | `cache-cleanup` | `true` | Delete stale images from registry after save |
 | `cache-cleanup-keep` | `2` | Number of old image versions to keep per step |
+| `hm-path` | | Path to a locally-built `hm` binary (skips install; used for dogfooding) |
 | `extra-args` | | Additional arguments passed to `hm run` |
 | `token` | `github.token` | GitHub token (needs `packages:write`, `packages:delete` for cleanup) |
 
@@ -212,7 +193,7 @@ steps:
 ```yaml
 steps:
   - uses: actions/checkout@v4
-  - uses: harmont-dev/actions-hm@v1
+  - uses: harmont-dev/actions-hm@main
     with:
       pipeline: ci
 ```
@@ -234,7 +215,7 @@ macOS runners have Docker available via colima/lima. Windows runners are not cur
 Yes. Set `cache-registry` to your registry hostname and provide a token with push/pull access:
 
 ```yaml
-- uses: harmont-dev/actions-hm@v1
+- uses: harmont-dev/actions-hm@main
   with:
     pipeline: ci
     cache-registry: registry.example.com
@@ -244,7 +225,7 @@ Yes. Set `cache-registry` to your registry hostname and provide a token with pus
 ### How do I disable caching entirely?
 
 ```yaml
-- uses: harmont-dev/actions-hm@v1
+- uses: harmont-dev/actions-hm@main
   with:
     pipeline: ci
     cache: 'false'

action.yml

@@ -54,6 +54,12 @@ inputs:
     description: Additional arguments passed to 'hm run'
     required: false
     default: ''
+  hm-path:
+    description: >
+      Path to the hm binary. Use when testing a locally-built binary
+      instead of an installed release. Overrides setup step.
+    required: false
+    default: ''
   token:
     description: >
       GitHub token (needs packages:write for cache, packages:delete for cleanup)
@@ -70,6 +76,7 @@ runs:
   steps:
     # --- Setup ---
     - name: Setup Harmont
+      if: inputs.hm-path == ''
       id: setup
       uses: ./setup
       with:
@@ -92,6 +99,7 @@ runs:
       working-directory: ${{ inputs.working-directory }}
       env:
         HM_NONINTERACTIVE: '1'
+        INPUT_HM_PATH: ${{ inputs.hm-path || 'hm' }}
         INPUT_PIPELINE: ${{ inputs.pipeline }}
         INPUT_PARALLELISM: ${{ inputs.parallelism }}
         INPUT_EXTRA_ARGS: ${{ inputs.extra-args }}
@@ -107,7 +115,7 @@ runs:
           read -ra extra <<< "$INPUT_EXTRA_ARGS"
           args+=("${extra[@]}")
         fi
-        hm run "${args[@]}"
+        "$INPUT_HM_PATH" run "${args[@]}"
 
     # --- Cache Save ---
     - name: Save Docker cache
@@ -119,4 +127,5 @@ runs:
         working-directory: ${{ inputs.working-directory }}
         cleanup: ${{ inputs.cache-cleanup }}
         cleanup-keep: ${{ inputs.cache-cleanup-keep }}
+        hm-path: ${{ inputs.hm-path || 'hm' }}
         token: ${{ inputs.token }}

cache-save/action.yml

@@ -3,7 +3,6 @@ description: >
   Push Docker images to a container registry after a harmont pipeline run.
   Automatically cleans up stale images no longer in the current manifest.
   Use with 'if: always()' to save cache even when the pipeline fails.
-
 inputs:
   registry:
     description: Container registry to push to
@@ -36,7 +35,12 @@ inputs:
       Token for registry auth (needs packages:write, packages:delete for cleanup).
     required: false
     default: ${{ github.token }}
-
+  hm-path:
+    description: >
+      Path to the hm binary. Defaults to 'hm' (assumes it's on PATH).
+      Use './target/debug/hm' or similar when testing a locally-built binary.
+    required: false
+    default: hm
 runs:
   using: composite
   steps:
@@ -54,13 +58,14 @@ runs:
       env:
         INPUT_REGISTRY_PREFIX: ${{ inputs.registry-prefix }}
         INPUT_REGISTRY: ${{ inputs.registry }}
+        INPUT_HM_PATH: ${{ inputs.hm-path }}
         GITHUB_REPOSITORY: ${{ github.repository }}
       working-directory: ${{ inputs.working-directory }}
       run: |
         prefix="${INPUT_REGISTRY_PREFIX:-${INPUT_REGISTRY}/${GITHUB_REPOSITORY}/harmont-cache}"
 
         echo "::group::Exporting image manifest"
-        hm cache save .harmont-cache/ > /dev/null
+        "$INPUT_HM_PATH" cache save .harmont-cache/ > /dev/null
         echo "::endgroup::"
 
         if [ ! -f .harmont-cache/manifest.json ]; then