add-host input

.github/workflows/ci.yml

@@ -416,6 +416,30 @@ jobs:
         if: always()
         uses: crazy-max/ghaction-dump-context@v1
 
+  addhost:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      -
+        name: Build
+        uses: ./
+        with:
+          context: ./test
+          file: ./test/addhost.Dockerfile
+          tags: name/app:latest
+          add-host: |
+            docker:10.180.0.1
+            foo:10.0.0.1
+      -
+        name: Dump context
+        if: always()
+        uses: crazy-max/ghaction-dump-context@v1
+
   multi:
     runs-on: ubuntu-latest
     strategy:

README.md

@@ -199,6 +199,7 @@ Following inputs can be used as `step.with` keys
 
 | Name                | Type     | Description                        |
 |---------------------|----------|------------------------------------|
+| `add-host`          | List/CSV | Add a [custom host-to-IP mapping](https://docs.docker.com/engine/reference/commandline/build/#add-entries-to-container-hosts-file---add-host) (e.g., `docker:10.180.0.1`) |
 | `allow`             | List/CSV | List of [extra privileged entitlement](https://github.com/docker/buildx/blob/master/docs/reference/buildx_build.md#allow) (e.g., `network.host,security.insecure`) |
 | `builder`           | String   | Builder instance (see [setup-buildx](https://github.com/docker/setup-buildx-action) action) |
 | `build-args`        | List     | List of build-time variables |

__tests__/context.test.ts

@@ -469,6 +469,7 @@ ccc`],
       new Map<string, string>([
         ['context', '.'],
         ['file', './test/Dockerfile'],
+        ['add-host', 'docker:10.180.0.1'],
         ['cgroup-parent', 'foo'],
         ['shm-size', '2g'],
         ['ulimit', `nofile=1024:1024
@@ -481,6 +482,7 @@ nproc=3`],
       [
         'buildx',
         'build',
+        '--add-host', 'docker:10.180.0.1',
         '--cgroup-parent', 'foo',
         '--file', './test/Dockerfile',
         '--iidfile', '/tmp/.docker-build-push-jest/iidfile',

action.yml

@@ -7,6 +7,9 @@ branding:
   color: 'blue'
 
 inputs:
+  add-host:
+    description: "Add a custom host-to-IP mapping (e.g., docker:10.180.0.1)"
+    required: false
   allow:
     description: "List of extra privileged entitlement (e.g., network.host,security.insecure)"
     required: false

src/context.ts

@@ -14,6 +14,7 @@ import * as handlebars from 'handlebars';
 let _defaultContext, _tmpDir: string;
 
 export interface Inputs {
+  addHost: string[];
   allow: string[];
   buildArgs: string[];
   builder: string;
@@ -67,6 +68,7 @@ export function tmpNameSync(options?: tmp.TmpNameOptions): string {
 
 export async function getInputs(defaultContext: string): Promise<Inputs> {
   return {
+    addHost: await getInputList('add-host'),
     allow: await getInputList('allow'),
     buildArgs: await getInputList('build-args', true),
     builder: core.getInput('builder'),
@@ -104,6 +106,9 @@ export async function getArgs(inputs: Inputs, defaultContext: string, buildxVers
 
 async function getBuildArgs(inputs: Inputs, defaultContext: string, buildxVersion: string): Promise<Array<string>> {
   let args: Array<string> = ['build'];
+  if (inputs.addHost.length > 0) {
+    args.push('--add-host', inputs.addHost.join(','));
+  }
   if (inputs.allow.length > 0) {
     args.push('--allow', inputs.allow.join(','));
   }

test/addhost.Dockerfile

@@ -0,0 +1,2 @@
+FROM busybox
+RUN cat /etc/hosts