Add feature to build multi-arch image (#27)

Since buildah now supports multi arch image
support (ref: https://github.com/containers/buildah/issues/1590)
This feature will allow building images for multiple
architectures.

Signed-off-by: divyansh42 <diagrawa@redhat.com>

.github/workflows/scratch_build.yml

@@ -78,7 +78,8 @@ jobs:
             -jar
             spring-petclinic-*.jar
           port: 8080
-      
+          archs: amd64,arm64
+
       - name: Echo Outputs
         run: | 
           echo "Image: ${{ steps.build_image.outputs.image }}"

README.md

@@ -21,6 +21,7 @@ After building your image, use [push-to-registry](https://github.com/redhat-acti
 
 | Input Name | Description | Default |
 | ---------- | ----------- | ------- |
+| archs | Architecture(s) to build the image(s) for. For multiple architectures, separate by a comma. If the workflow is running on a self-hosted runner, [qemu-user-static](https://github.com/marketplace/actions/docker-setup-qemu) can be used to install the `qemu-user-static` dependency. | `amd64`
 | build-args | Build arguments to pass to the Docker build using `--build-arg`, if using a Dockerfile that requires ARGs. Use the form `arg_name=arg_value`, and separate arguments with newlines. | None
 | context | Path to directory to use as the build context. | `.`
 | dockerfiles | The list of Dockerfile paths to perform a build using docker instructions. This is a multiline input to allow multiple Dockerfiles. | **Must be provided**
@@ -32,6 +33,7 @@ After building your image, use [push-to-registry](https://github.com/redhat-acti
 
 | Input Name | Description | Default |
 | ---------- | ----------- | ------- |
+| archs | Architecture(s) to build the image(s) for. For multiple architectures, separate by a comma. If the workflow is running on a self-hosted runner, [qemu-user-static](https://github.com/marketplace/actions/docker-setup-qemu) can be used to install the `qemu-user-static` dependency. | `amd64`
 | base-image | The base image to use for the container. | **Must be provided**
 | content | Paths to files or directories to copy inside the container to create the file image. This is a multiline input to allow you to copy multiple files/directories.| None
 | context | Path to directory to use as the build context. | `.`

action.yml

@@ -44,6 +44,12 @@ inputs:
     description: 'Set to true to build using the OCI image format instead of the Docker image format'
     default: 'false'
     required: false
+  archs:
+    description: |
+      Architecture(s) to build the image(s) for. For multiple architectures,
+      separate by a comma.
+    default: 'amd64'
+    required: false
 outputs:
   image:
     description: 'Name of the image built'

git-hooks/pre-commit

@@ -6,5 +6,6 @@
 echo "----- Pre-commit -----"
 set -ex
 npx action-io-generator -o src/generated/inputs-outputs.ts
+npm run lint
 npm run bundle
 git add -v dist/ src/generated

src/buildah.ts

@@ -8,11 +8,12 @@ export interface BuildahConfigSettings {
     envs?: string[];
     port?: string;
     workingdir?: string;
+    archs?: string;
 }
 
 interface Buildah {
     buildUsingDocker(
-        image: string, context: string, dockerFiles: string[], buildArgs: string[], useOCI: boolean,
+        image: string, context: string, dockerFiles: string[], buildArgs: string[], useOCI: boolean, archs: string,
     ): Promise<CommandResult>;
     from(baseImage: string): Promise<CommandResult>;
     copy(container: string, contentToCopy: string[]): Promise<CommandResult | undefined>;
@@ -32,9 +33,13 @@ export class BuildahCli implements Buildah {
     }
 
     async buildUsingDocker(
-        image: string, context: string, dockerFiles: string[], buildArgs: string[], useOCI: boolean,
+        image: string, context: string, dockerFiles: string[], buildArgs: string[], useOCI: boolean, archs: string
     ): Promise<CommandResult> {
         const args: string[] = [ "bud" ];
+        if (archs) {
+            args.push("--arch");
+            args.push(archs);
+        }
         dockerFiles.forEach((file) => {
             args.push("-f");
             args.push(file);
@@ -90,6 +95,10 @@ export class BuildahCli implements Buildah {
                 args.push(env);
             });
         }
+        if (settings.archs) {
+            args.push("--arch");
+            args.push(settings.archs);
+        }
         args.push(container);
         return this.execute(args);
     }

src/generated/inputs-outputs.ts

@@ -1,5 +1,12 @@
 // This file was auto-generated by action-io-generator. Do not edit by hand!
 export enum Inputs {
+    /**
+     * Architecture(s) to build the image(s) for. For multiple architectures,
+     * separate by a comma.
+     * Required: false
+     * Default: "amd64"
+     */
+    ARCHS = "archs",
     /**
      * The base image to use to create a new container image
      * Required: true

src/index.ts

@@ -20,12 +20,15 @@ export async function run(): Promise<void> {
     const tagsList: string[] = tags.split(" ");
     const newImage = `${image}:${tagsList[0]}`;
     const useOCI = core.getInput(Inputs.OCI) === "true";
+    let archs: string | undefined = core.getInput(Inputs.ARCHS);
+    // remove white spaces (if any) in archs input
+    archs = archs.replace(/\s+/g, "");
 
     if (dockerFiles.length !== 0) {
-        await doBuildUsingDockerFiles(cli, newImage, workspace, dockerFiles, useOCI);
+        await doBuildUsingDockerFiles(cli, newImage, workspace, dockerFiles, useOCI, archs);
     }
     else {
-        await doBuildFromScratch(cli, newImage, useOCI);
+        await doBuildFromScratch(cli, newImage, useOCI, archs);
     }
 
     if (tagsList.length > 1) {
@@ -36,7 +39,7 @@ export async function run(): Promise<void> {
 }
 
 async function doBuildUsingDockerFiles(
-    cli: BuildahCli, newImage: string, workspace: string, dockerFiles: string[], useOCI: boolean,
+    cli: BuildahCli, newImage: string, workspace: string, dockerFiles: string[], useOCI: boolean, archs: string
 ): Promise<void> {
     if (dockerFiles.length === 1) {
         core.info(`Performing build from Dockerfile`);
@@ -48,11 +51,11 @@ async function doBuildUsingDockerFiles(
     const context = path.join(workspace, core.getInput(Inputs.CONTEXT));
     const buildArgs = getInputList(Inputs.BUILD_ARGS);
     const dockerFileAbsPaths = dockerFiles.map((file) => path.join(workspace, file));
-    await cli.buildUsingDocker(newImage, context, dockerFileAbsPaths, buildArgs, useOCI);
+    await cli.buildUsingDocker(newImage, context, dockerFileAbsPaths, buildArgs, useOCI, archs);
 }
 
 async function doBuildFromScratch(
-    cli: BuildahCli, newImage: string, useOCI: boolean,
+    cli: BuildahCli, newImage: string, useOCI: boolean, archs: string
 ): Promise<void> {
     core.info(`Performing build from scratch`);
 
@@ -73,6 +76,7 @@ async function doBuildFromScratch(
         port,
         workingdir: workingDir,
         envs,
+        archs,
     };
     await cli.config(containerId, newImageConfig);
     await cli.commit(containerId, newImage, useOCI);