From f231da7d1492c5a429585dcc050a1b5b014d1945 Mon Sep 17 00:00:00 2001
From: CrazyMax <1951866+crazy-max@users.noreply.github.com>
Date: Tue, 19 Dec 2023 13:56:22 +0100
Subject: [PATCH] git context support

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>
---
 .github/workflows/ci.yml | 19 +++++++++++++++++
 README.md                | 44 ++++++++++++++++++++++++++++++++++++++++
 package.json             |  3 ++-
 src/context.ts           | 11 +++++++---
 4 files changed, 73 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 82ee44c..a4ebd3c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -398,3 +398,22 @@ jobs:
         with:
           files: |
             ./test/config.hcl
+
+  git-context:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v4
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+        with:
+          version: ${{ inputs.buildx-version || env.BUILDX_VERSION }}
+          driver-opts: |
+            image=${{ inputs.buildkit-image || env.BUILDKIT_IMAGE }}
+      -
+        name: Build
+        uses: ./
+        with:
+          source: "{{defaultContext}}"
diff --git a/README.md b/README.md
index 979ac84..9b71979 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,8 @@ as a high-level build command.
 ___
 
 * [Usage](#usage)
+  * [Default](#default)
+  * [Git context](#git-context)
 * [Customizing](#customizing)
   * [inputs](#inputs)
   * [outputs](#outputs)
@@ -23,6 +25,8 @@ ___
 
 ## Usage
 
+### Default
+
 ```yaml
 name: ci
 
@@ -54,6 +58,46 @@ jobs:
           push: true
 ```
 
+### Git context
+
+By default, this action will use the local bake definition, so you need to
+use the [`actions/checkout`](https://github.com/actions/checkout/) action to
+check out the repository.
+
+If you want to use a remote bake definition, you can use the `source` input
+to specify a remote bake definition to use. Default Git context can be provided
+using the [Handlebars template](https://handlebarsjs.com/guide/) expression
+`{{defaultContext}}`:
+
+```yaml
+name: ci
+
+on:
+  push:
+    branches:
+      - 'master'
+
+jobs:
+  bake:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      -
+        name: Login to DockerHub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      -
+        name: Build and push
+        uses: docker/bake-action@v4
+        with:
+          source: "{{defaultContext}}"
+          push: true
+```
+
 ## Customizing
 
 ### inputs
diff --git a/package.json b/package.json
index 5543ac2..d376220 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,8 @@
   "license": "Apache-2.0",
   "dependencies": {
     "@actions/core": "^1.10.1",
-    "@docker/actions-toolkit": "^0.14.0"
+    "@docker/actions-toolkit": "^0.14.0",
+    "handlebars": "^4.7.8"
   },
   "devDependencies": {
     "@types/node": "^20.5.9",
diff --git a/src/context.ts b/src/context.ts
index a55e3e5..fbd1843 100644
--- a/src/context.ts
+++ b/src/context.ts
@@ -1,5 +1,7 @@
 import * as core from '@actions/core';
+import * as handlebars from 'handlebars';
 import {Bake} from '@docker/actions-toolkit/lib/buildx/bake';
+import {Context} from '@docker/actions-toolkit/lib/context';
 import {Inputs as BuildxInputs} from '@docker/actions-toolkit/lib/buildx/inputs';
 import {GitHub} from '@docker/actions-toolkit/lib/github';
 import {Toolkit} from '@docker/actions-toolkit/lib/toolkit';
@@ -48,8 +50,11 @@ export async function getArgs(inputs: Inputs, toolkit: Toolkit): Promise<Array<s
 
 async function getBakeArgs(inputs: Inputs, toolkit: Toolkit): Promise<Array<string>> {
   const args: Array<string> = ['bake'];
-  if (inputs.source) {
-    args.push(inputs.source);
+  const source = handlebars.compile(inputs.source)({
+    defaultContext: Context.gitContext()
+  });
+  if (source) {
+    args.push(source);
   }
   await Util.asyncForEach(inputs.files, async file => {
     args.push('--file', file);
@@ -61,7 +66,7 @@ async function getBakeArgs(inputs: Inputs, toolkit: Toolkit): Promise<Array<stri
     args.push('--metadata-file', BuildxInputs.getBuildMetadataFilePath());
   }
   if (await toolkit.buildx.versionSatisfies('>=0.10.0')) {
-    const bakedef = await toolkit.bake.parseDefinitions([...inputs.files, inputs.source], inputs.targets, inputs.set, inputs.load, inputs.push, inputs.workdir);
+    const bakedef = await toolkit.bake.parseDefinitions([...inputs.files, source], inputs.targets, inputs.set, inputs.load, inputs.push, inputs.workdir);
     if (inputs.provenance) {
       args.push('--provenance', inputs.provenance);
     } else if ((await toolkit.buildkit.versionSatisfies(inputs.builder, '>=0.11.0')) && !Bake.hasDockerExporter(bakedef, inputs.load)) {