First cut at actions for dependency-graph

- Dependency graph init-script references published version of plugin jar.
- `dependency-graph-generate` action will:
     - Provision Gradle if required
     - Execute Gradle with dependency-graph plugin to generate graph JSON
     - Upload dependency-graph JSON file as workflow artifact
- `dependency-graph-submit` action will:
    - Download dependency-graph JSON artifact
    - Submit the graph via the GitHub dependency submission API

src/dependency-graph.ts

@@ -0,0 +1,155 @@
+import * as core from '@actions/core'
+import * as artifact from '@actions/artifact'
+import * as github from '@actions/github'
+import * as glob from '@actions/glob'
+import * as toolCache from '@actions/tool-cache'
+import {Octokit} from '@octokit/rest'
+
+import * as path from 'path'
+import fs from 'fs'
+
+import * as execution from './execution'
+import * as layout from './repository-layout'
+
+const DEPENDENCY_GRAPH_ARTIFACT = 'dependency-graph'
+const DEPENDENCY_GRAPH_FILE = 'dependency-graph.json'
+
+export async function generateDependencyGraph(executable: string | undefined): Promise<void> {
+    const workspaceDirectory = layout.workspaceDirectory()
+    const buildRootDirectory = layout.buildRootDirectory()
+    const buildPath = getRelativePathFromWorkspace(buildRootDirectory)
+
+    const initScript = path.resolve(
+        __dirname,
+        '..',
+        '..',
+        'src',
+        'resources',
+        'init-scripts',
+        'github-dependency-graph.init.gradle'
+    )
+    const args = [
+        `-Dorg.gradle.github.env.GRADLE_BUILD_PATH=${buildPath}`,
+        '--init-script',
+        initScript,
+        ':GitHubDependencyGraphPlugin_generateDependencyGraph'
+    ]
+
+    await execution.executeGradleBuild(executable, buildRootDirectory, args)
+    const dependencyGraphJson = copyDependencyGraphToBuildRoot(buildRootDirectory)
+
+    const artifactClient = artifact.create()
+    artifactClient.uploadArtifact(DEPENDENCY_GRAPH_ARTIFACT, [dependencyGraphJson], workspaceDirectory)
+}
+
+function copyDependencyGraphToBuildRoot(buildRootDirectory: string): string {
+    const sourceFile = path.resolve(
+        buildRootDirectory,
+        'build',
+        'reports',
+        'github-dependency-graph-plugin',
+        'github-dependency-snapshot.json'
+    )
+
+    const destFile = path.resolve(buildRootDirectory, DEPENDENCY_GRAPH_FILE)
+    fs.copyFileSync(sourceFile, destFile)
+    return destFile
+}
+
+export async function submitDependencyGraph(): Promise<void> {
+    const workspaceDirectory = layout.workspaceDirectory()
+    const octokit: Octokit = getOctokit()
+
+    for (const jsonFile of await retrieveDependencyGraphs(octokit, workspaceDirectory)) {
+        const jsonContent = fs.readFileSync(jsonFile, 'utf8')
+
+        const jsonObject = JSON.parse(jsonContent)
+        jsonObject.owner = github.context.repo.owner
+        jsonObject.repo = github.context.repo.repo
+        const response = await octokit.request('POST /repos/{owner}/{repo}/dependency-graph/snapshots', jsonObject)
+
+        const relativeJsonFile = getRelativePathFromWorkspace(jsonFile)
+        core.info(`Submitted ${relativeJsonFile}: ${JSON.stringify(response)}`)
+        core.notice(`Submitted ${relativeJsonFile}: ${response.data.message}`)
+    }
+}
+
+async function findDependencyGraphFiles(dir: string): Promise<string[]> {
+    const globber = await glob.create(`${dir}/**/${DEPENDENCY_GRAPH_FILE}`)
+    const graphFiles = globber.glob()
+    core.info(`Found graph files in ${dir}: ${graphFiles}`)
+    return graphFiles
+}
+
+async function retrieveDependencyGraphs(octokit: Octokit, workspaceDirectory: string): Promise<string[]> {
+    if (github.context.payload.workflow_run) {
+        return await retrieveDependencyGraphsForWorkflowRun(
+            github.context.payload.workflow_run.id,
+            octokit,
+            workspaceDirectory
+        )
+    }
+    return retrieveDependencyGraphsForCurrentWorkflow(workspaceDirectory)
+}
+
+async function retrieveDependencyGraphsForWorkflowRun(
+    runId: number,
+    octokit: Octokit,
+    workspaceDirectory: string
+): Promise<string[]> {
+    // Find the workflow run artifacts named "dependency-graph"
+    const artifacts = await octokit.rest.actions.listWorkflowRunArtifacts({
+        owner: github.context.repo.owner,
+        repo: github.context.repo.repo,
+        run_id: runId
+    })
+
+    const matchArtifact = artifacts.data.artifacts.find(candidate => {
+        return candidate.name === DEPENDENCY_GRAPH_ARTIFACT
+    })
+
+    if (matchArtifact === undefined) {
+        throw new Error(`Dependency graph artifact not found. Has it been generated by workflow run '${runId}'?`)
+    }
+
+    // Download the dependency-graph artifact
+    const download = await octokit.rest.actions.downloadArtifact({
+        owner: github.context.repo.owner,
+        repo: github.context.repo.repo,
+        artifact_id: matchArtifact.id,
+        archive_format: 'zip'
+    })
+
+    const downloadBuffer = download.data as ArrayBuffer
+    const downloadZip = path.resolve(workspaceDirectory, 'dependency-graph.zip')
+    fs.writeFileSync(downloadZip, Buffer.from(downloadBuffer))
+
+    // Expance the dependency-graph zip and locate each dependency-graph JSON file
+    const extractDir = path.resolve(workspaceDirectory, 'dependency-graph')
+    const extracted = await toolCache.extractZip(downloadZip, extractDir)
+    core.info(`Extracted dependency graph artifacts to ${extracted}: ${fs.readdirSync(extracted)}`)
+
+    return findDependencyGraphFiles(extracted)
+}
+
+async function retrieveDependencyGraphsForCurrentWorkflow(workspaceDirectory: string): Promise<string[]> {
+    const artifactClient = artifact.create()
+    const downloadPath = path.resolve(workspaceDirectory, 'dependency-graph')
+    await artifactClient.downloadArtifact(DEPENDENCY_GRAPH_ARTIFACT, downloadPath)
+    return await findDependencyGraphFiles(downloadPath)
+}
+
+function getOctokit(): Octokit {
+    return new Octokit({
+        auth: getGithubToken()
+    })
+}
+
+function getGithubToken(): string {
+    return core.getInput('github-token', {required: true})
+}
+
+function getRelativePathFromWorkspace(file: string): string {
+    const workspaceDirectory = layout.workspaceDirectory()
+    return path.relative(workspaceDirectory, file)
+}