Fix error handling

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

README.md

@@ -6,9 +6,7 @@
 
 Buildah is a GitHub Action for building OCI-compatible (Docker- and Kubernetes-compatible) images quickly and easily.
 
-Buildah action works only on Linux distributions, and it is not supported on Windows or Mac platforms at this time.
-
-Note that GitHub's [Ubuntu Environments](https://github.com/actions/virtual-environments#available-environments) (ubuntu-20.04 and ubuntu-18.04) come with buildah 1.17.0 installed. If you are not using these environments, you must first [install buildah](https://github.com/containers/buildah/blob/master/install.md).
+Buildah only works on Linux. GitHub's [Ubuntu Environments](https://github.com/actions/virtual-environments#available-environments) (`ubuntu-18.04` and newer) come with buildah installed. If you are not using these environments, or if you want to use a different version, you must first [install buildah](https://github.com/containers/buildah/blob/master/install.md).
 
 After building your image, use [push-to-registry](https://github.com/redhat-actions/push-to-registry) to push the image and make it pullable.
 

src/buildah.ts

@@ -1,6 +1,5 @@
 import * as core from "@actions/core";
 import * as exec from "@actions/exec";
-import { CommandResult } from "./types";
 
 interface Buildah {
     buildUsingDocker(image: string, context: string, dockerFiles: string[], buildArgs: string[]): Promise<CommandResult>;
@@ -38,29 +37,27 @@ export class BuildahCli implements Buildah {
         args.push('-t');
         args.push(image);
         args.push(context);
-        return await this.execute(args);
+        return this.execute(args);
     }
 
     async from(baseImage: string): Promise<CommandResult> {
-        return await this.execute(['from', baseImage]);
+        return this.execute(['from', baseImage]);
     }
 
-    async copy(container: string, contentToCopy: string[], path?: string): Promise<CommandResult> {
+    async copy(container: string, contentToCopy: string[], path?: string): Promise<CommandResult | undefined> {
+        if (contentToCopy.length === 0) {
+            return undefined;
+        }
+
         core.debug('copy');
         core.debug(container);
-        let result: CommandResult;
         for (const content of contentToCopy) {
             const args: string[] = ["copy", container, content];
             if (path) {
                 args.push(path);
             }
-            result = await this.execute(args);
-            if (result.succeeded === false) {
-                return result;
-            }
+            return this.execute(args);
         }
-
-        return result;
     }
 
     async config(container: string, settings: BuildahConfigSettings): Promise<CommandResult> {
@@ -82,15 +79,15 @@ export class BuildahCli implements Buildah {
             });
         }
         args.push(container);
-        return await this.execute(args);
+        return this.execute(args);
     }
 
     async commit(container: string, newImageName: string, flags: string[] = []): Promise<CommandResult> {
         core.debug('commit');
         core.debug(container);
         core.debug(newImageName);
         const args: string[] = ["commit", ...flags, container, newImageName];
-        return await this.execute(args);
+        return this.execute(args);
     }
 
     private convertArrayToStringArg(args: string[]): string {
@@ -103,25 +100,27 @@ export class BuildahCli implements Buildah {
 
     private async execute(args: string[]): Promise<CommandResult> {
         if (!this.executable) {
-          return Promise.reject(new Error('Unable to call buildah executable'));
+          throw new Error('Unable to call buildah executable');
         }
 
-        let output = '';
-        let error = '';
+        let stdOut = '';
+        let stdErr = '';
 
         const options: exec.ExecOptions = {};
         options.listeners = {
             stdout: (data: Buffer): void => {
-                output += data.toString();
+                stdOut += data.toString();
             },
             stderr: (data: Buffer): void => {
-                error += data.toString();
+                stdErr += data.toString();
             }
         };
         const exitCode = await exec.exec(this.executable, args, options);
-        if (exitCode === 1) {
-            return Promise.resolve({ succeeded: false, error });
+        if (exitCode !== 0) {
+            throw new Error(`Buildah exited with code ${exitCode}`);
         }
-        return Promise.resolve({ succeeded: true, output });
+        return {
+            exitCode, output: stdOut, error: stdErr
+        };
     }
 }

src/index.ts

@@ -9,7 +9,7 @@ import { Language } from 'language-recognizer/lib/types';
 export async function run(): Promise<void> {
 
     if (process.env.RUNNER_OS !== 'Linux') {
-        return Promise.reject(new Error('Only linux platform is supported at this time.'));
+        throw new Error('buildah, and therefore this action, only works on Linux. Please use a Linux runner.');
     }
 
     // get buildah cli
@@ -21,23 +21,23 @@ export async function run(): Promise<void> {
     const newImage = `${core.getInput('image', { required: true })}:${core.getInput('tag', { required: true })}`;
 
     if (dockerFiles.length !== 0) {
-        doBuildUsingDockerFiles(cli, newImage, workspace, dockerFiles);
+        await doBuildUsingDockerFiles(cli, newImage, workspace, dockerFiles);
     } else {
-        doBuildFromScratch(cli, newImage, workspace);
+        await doBuildFromScratch(cli, newImage, workspace);
     }
 }
 
 async function doBuildUsingDockerFiles(cli: BuildahCli, newImage: string, workspace: string, dockerFiles: string[]): Promise<void> {
+    core.info(`Performing Docker build`);
     const context = path.join(workspace, core.getInput('context'));
     const buildArgs = getInputList(core.getInput('build-args'));
     dockerFiles = dockerFiles.map(file => path.join(workspace, file));
-    const build = await cli.buildUsingDocker(newImage, context, dockerFiles, buildArgs);
-    if (build.succeeded === false) {
-        return Promise.reject(new Error('Failed building an image from docker files.'));
-    }
+    await cli.buildUsingDocker(newImage, context, dockerFiles, buildArgs);
 }
 
-async function doBuildFromScratch(cli: BuildahCli, newImage: string, workspace: string) {
+async function doBuildFromScratch(cli: BuildahCli, newImage: string, workspace: string): Promise<void> {
+    core.info(`Performing build from scratch`)
+
     let baseImage = core.getInput('base-image');
     const content = getInputList('content');
     const entrypoint = getInputList('entrypoint');
@@ -52,39 +52,26 @@ async function doBuildFromScratch(cli: BuildahCli, newImage: string, workspace:
             const languages = await recognizer.detectLanguages(workspace);
             baseImage = await getSuggestedBaseImage(languages);
             if (!baseImage) {
-                return Promise.reject(new Error('No base image found to create a new container'));
+                throw new Error('No base image found to create a new container');
             }
         } else {
-            return Promise.reject(new Error('No base image found to create a new container'));
+            throw new Error('No base image found to create a new container');
         }
     }
 
     const container = await cli.from(baseImage);
-    if (container.succeeded === false) {
-        return Promise.reject(new Error(container.reason));
-    }
     const containerId = container.output.replace('\n', '');
 
-    const copyResult = await cli.copy(containerId, content);
-    if (copyResult.succeeded === false) {
-        return Promise.reject(new Error(copyResult.reason));
-    }
+    await cli.copy(containerId, content);
 
     const newImageConfig: BuildahConfigSettings = {
         entrypoint: entrypoint,
         port: port,
         workingdir: workingDir,
         envs: envs
     };
-    const configResult = await cli.config(containerId, newImageConfig);
-    if (configResult.succeeded === false) {
-        return Promise.reject(new Error(configResult.reason));
-    }
-
-    const commit = await cli.commit(containerId, newImage, ['--squash']);
-    if (commit.succeeded === false) {
-        return Promise.reject(new Error(commit.reason));
-    }
+    await cli.config(containerId, newImageConfig);
+    await cli.commit(containerId, newImage, ['--squash']);
 }
 
 function getInputList(name: string): string[] {
@@ -117,7 +104,6 @@ async function getSuggestedBaseImage(languages: Language[]): Promise<string> {
 }
 
 async function getBaseImageByLanguage(language: Language): Promise<string> {
-    // eslint-disable-next-line no-undef
     const rawData = await fs.readFile(path.join(__dirname, '..', 'language-image.json'), 'utf-8');
     const languageImageJSON = JSON.parse(rawData);
     return languageImageJSON[language.name];

src/types.ts

@@ -1,11 +1,5 @@
-export interface CommandSucceeeded {
-    readonly succeeded: true;
-    readonly output?: string;
-}
-
-export interface CommandFailed {
-    readonly succeeded: false;
-    readonly reason?: string;
-}
-
-export type CommandResult = CommandFailed | CommandSucceeeded;
+type CommandResult = {
+    exitCode: number
+    output: string
+    error: string
+};