Default to docker image format

Signed-off-by: Tim Etchells <tetchell@redhat.com>

README.md

@@ -49,6 +49,15 @@ After building your image, use [push-to-registry](https://github.com/redhat-acti
     </td>
   </tr>
 
+  <tr>
+    <td>oci</td>
+    <td>No</td>
+    <td>
+      Build the image using the OCI format, instead of the Docker format.<br>
+      By default, this is <code>false</code>, because images built using the OCI format have <a href="https://github.com/docker/hub-feedback/issues/1871">issues</a> when published to Dockerhub.
+    </td>
+  </tr>
+
   <tr>
     <td>context</td>
     <td>No</td>

action.yml

@@ -40,6 +40,10 @@ inputs:
   build-args:
     description: 'List of --build-args to pass to buildah.'
     required: false
+  oci:
+    description: 'Set to true to build using the OCI image format instead of the Docker image format.'
+    default: 'false'
+    required: false
 runs:
   using: 'node12'
   main: 'dist/index.js'

src/buildah.ts

@@ -2,11 +2,11 @@ import * as core from "@actions/core";
 import * as exec from "@actions/exec";
 
 interface Buildah {
-    buildUsingDocker(image: string, context: string, dockerFiles: string[], buildArgs: string[]): Promise<CommandResult>;
+    buildUsingDocker(image: string, context: string, dockerFiles: string[], buildArgs: string[], useOCI: boolean): Promise<CommandResult>;
     from(baseImage: string): Promise<CommandResult>;
     copy(container: string, contentToCopy: string[]): Promise<CommandResult>;
     config(container: string, setting: {}): Promise<CommandResult>;
-    commit(container: string, newImageName: string, flags?: string[]): Promise<CommandResult>;
+    commit(container: string, newImageName: string, useOCI: boolean): Promise<CommandResult>;
 }
 
 export interface BuildahConfigSettings {
@@ -24,7 +24,11 @@ export class BuildahCli implements Buildah {
         this.executable = executable;
     }
 
-    async buildUsingDocker(image: string, context: string, dockerFiles: string[], buildArgs: string[]): Promise<CommandResult> {
+    private getImageFormatOption(useOCI: boolean): string[] {
+        return [ '--format', useOCI ? 'oci' : 'docker' ];
+    }
+
+    async buildUsingDocker(image: string, context: string, dockerFiles: string[], buildArgs: string[], useOCI: boolean): Promise<CommandResult> {
         const args: string[] = ['bud'];
         dockerFiles.forEach(file => {
             args.push('-f');
@@ -33,7 +37,8 @@ export class BuildahCli implements Buildah {
         buildArgs.forEach((buildArg) => {
             args.push('--build-arg');
             args.push(buildArg);
-        })
+        });
+        args.push(...this.getImageFormatOption(useOCI));
         args.push('-t');
         args.push(image);
         args.push(context);
@@ -82,11 +87,11 @@ export class BuildahCli implements Buildah {
         return this.execute(args);
     }
 
-    async commit(container: string, newImageName: string, flags: string[] = []): Promise<CommandResult> {
+    async commit(container: string, newImageName: string, useOCI: boolean): Promise<CommandResult> {
         core.debug('commit');
         core.debug(container);
         core.debug(newImageName);
-        const args: string[] = ["commit", ...flags, container, newImageName];
+        const args: string[] = [ 'commit', ...this.getImageFormatOption(useOCI), '--squash', container, newImageName ];
         return this.execute(args);
     }
 

src/index.ts

@@ -20,16 +20,18 @@ export async function run(): Promise<void> {
     let dockerFiles = getInputList('dockerfiles');
     const newImage = `${core.getInput('image', { required: true })}:${core.getInput('tag', { required: true })}`;
 
+    const useOCI = core.getInput("useOCI") === "true";
+
     if (dockerFiles.length !== 0) {
-        await doBuildUsingDockerFiles(cli, newImage, workspace, dockerFiles);
+        await doBuildUsingDockerFiles(cli, newImage, workspace, dockerFiles, useOCI);
     } else {
-        await doBuildFromScratch(cli, newImage, workspace);
+        await doBuildFromScratch(cli, newImage, workspace, useOCI);
     }
 
     core.setOutput("image", newImage);
 }
 
-async function doBuildUsingDockerFiles(cli: BuildahCli, newImage: string, workspace: string, dockerFiles: string[]): Promise<void> {
+async function doBuildUsingDockerFiles(cli: BuildahCli, newImage: string, workspace: string, dockerFiles: string[], useOCI: boolean): Promise<void> {
     if (dockerFiles.length === 1) {
         core.info(`Performing build from Dockerfile`);
     }
@@ -40,10 +42,10 @@ async function doBuildUsingDockerFiles(cli: BuildahCli, newImage: string, worksp
     const context = path.join(workspace, core.getInput('context'));
     const buildArgs = getInputList('build-args');
     dockerFiles = dockerFiles.map(file => path.join(workspace, file));
-    await cli.buildUsingDocker(newImage, context, dockerFiles, buildArgs);
+    await cli.buildUsingDocker(newImage, context, dockerFiles, buildArgs, useOCI);
 }
 
-async function doBuildFromScratch(cli: BuildahCli, newImage: string, workspace: string): Promise<void> {
+async function doBuildFromScratch(cli: BuildahCli, newImage: string, workspace: string, useOCI: boolean): Promise<void> {
     core.info(`Performing build from scratch`)
 
     let baseImage = core.getInput('base-image');
@@ -79,7 +81,7 @@ async function doBuildFromScratch(cli: BuildahCli, newImage: string, workspace:
         envs: envs
     };
     await cli.config(containerId, newImageConfig);
-    await cli.commit(containerId, newImage, ['--squash']);
+    await cli.commit(containerId, newImage, useOCI);
 }
 
 function getInputList(name: string): string[] {