Use GitHub releases to download python versions (#85)

This pull-request improves `setup-python` action to add ability to download specific version of Python on flight if it is not available by default.

**Details:**
`setup-python` action will download and install specific Python version from GitHub releases ([actions/python-versions](https://github.com/actions/python-versions/releases)) in case the version is not found in the local cache. All versions of Python available for installation are published in [actions/python-versions](https://github.com/actions/python-versions) repository.
All available versions are listed in the [version-manifest.json](https://github.com/actions/python-versions/blob/master/versions-manifest.json) file.

**Installation time:**

- Ubuntu / macOS: 10-20 seconds
- Windows: ~ 1 minute (mostly related to fact that we use MSI installer for Python on Windows)

Co-authored-by: MaksimZhukov <v-mazhuk@microsoft.com>
Co-authored-by: Konrad Pabjan <konradpabjan@github.com>
Co-authored-by: Brian Cristante <33549821+brcrista@users.noreply.github.com>

src/find-python.ts

@@ -3,22 +3,7 @@ import * as path from 'path';
 
 import * as semver from 'semver';
 
-let cacheDirectory = process.env['RUNNER_TOOLSDIRECTORY'] || '';
-
-if (!cacheDirectory) {
-  let baseLocation;
-  if (process.platform === 'win32') {
-    // On windows use the USERPROFILE env variable
-    baseLocation = process.env['USERPROFILE'] || 'C:\\';
-  } else {
-    if (process.platform === 'darwin') {
-      baseLocation = '/Users';
-    } else {
-      baseLocation = '/home';
-    }
-  }
-  cacheDirectory = path.join(baseLocation, 'actions', 'cache');
-}
+import * as installer from './install-python';
 
 import * as core from '@actions/core';
 import * as tc from '@actions/tool-cache';
@@ -92,29 +77,33 @@ async function useCpythonVersion(
   const semanticVersionSpec = pythonVersionToSemantic(desugaredVersionSpec);
   core.debug(`Semantic version spec of ${version} is ${semanticVersionSpec}`);
 
-  const installDir: string | null = tc.find(
+  let installDir: string | null = tc.find(
     'Python',
     semanticVersionSpec,
     architecture
   );
   if (!installDir) {
-    // Fail and list available versions
-    const x86Versions = tc
-      .findAllVersions('Python', 'x86')
-      .map(s => `${s} (x86)`)
-      .join(os.EOL);
+    core.info(
+      `Version ${semanticVersionSpec} was not found in the local cache`
+    );
+    const foundRelease = await installer.findReleaseFromManifest(
+      semanticVersionSpec,
+      architecture
+    );
 
-    const x64Versions = tc
-      .findAllVersions('Python', 'x64')
-      .map(s => `${s} (x64)`)
-      .join(os.EOL);
+    if (foundRelease && foundRelease.files && foundRelease.files.length > 0) {
+      core.info(`Version ${semanticVersionSpec} is available for downloading`);
+      await installer.installCpythonFromRelease(foundRelease);
 
+      installDir = tc.find('Python', semanticVersionSpec, architecture);
+    }
+  }
+
+  if (!installDir) {
     throw new Error(
       [
         `Version ${version} with arch ${architecture} not found`,
-        'Available versions:',
-        x86Versions,
-        x64Versions
+        `The list of all available versions can be found here: ${installer.MANIFEST_URL}`
       ].join(os.EOL)
     );
   }

src/install-python.ts

@@ -0,0 +1,65 @@
+import * as path from 'path';
+import * as core from '@actions/core';
+import * as tc from '@actions/tool-cache';
+import * as exec from '@actions/exec';
+import {ExecOptions} from '@actions/exec/lib/interfaces';
+
+const AUTH_TOKEN = core.getInput('token');
+const MANIFEST_REPO_OWNER = 'actions';
+const MANIFEST_REPO_NAME = 'python-versions';
+export const MANIFEST_URL = `https://raw.githubusercontent.com/${MANIFEST_REPO_OWNER}/${MANIFEST_REPO_NAME}/master/versions-manifest.json`;
+
+const IS_WINDOWS = process.platform === 'win32';
+
+export async function findReleaseFromManifest(
+  semanticVersionSpec: string,
+  architecture: string
+): Promise<tc.IToolRelease | undefined> {
+  const manifest: tc.IToolRelease[] = await tc.getManifestFromRepo(
+    MANIFEST_REPO_OWNER,
+    MANIFEST_REPO_NAME,
+    AUTH_TOKEN
+  );
+  return await tc.findFromManifest(
+    semanticVersionSpec,
+    true,
+    manifest,
+    architecture
+  );
+}
+
+async function installPython(workingDirectory: string) {
+  const options: ExecOptions = {
+    cwd: workingDirectory,
+    silent: true,
+    listeners: {
+      stdout: (data: Buffer) => {
+        core.debug(data.toString().trim());
+      }
+    }
+  };
+
+  if (IS_WINDOWS) {
+    await exec.exec('powershell', ['./setup.ps1'], options);
+  } else {
+    await exec.exec('bash', ['./setup.sh'], options);
+  }
+}
+
+export async function installCpythonFromRelease(release: tc.IToolRelease) {
+  const downloadUrl = release.files[0].download_url;
+
+  core.info(`Download from "${downloadUrl}"`);
+  const pythonPath = await tc.downloadTool(downloadUrl, undefined, AUTH_TOKEN);
+  const fileName = path.basename(pythonPath, '.zip');
+  core.info('Extract downloaded archive');
+  let pythonExtractedFolder;
+  if (IS_WINDOWS) {
+    pythonExtractedFolder = await tc.extractZip(pythonPath, `./${fileName}`);
+  } else {
+    pythonExtractedFolder = await tc.extractTar(pythonPath, `./${fileName}`);
+  }
+
+  core.info('Execute installation script');
+  await installPython(pythonExtractedFolder);
+}

src/setup-python.ts

@@ -1,12 +1,13 @@
 import * as core from '@actions/core';
 import * as finder from './find-python';
 import * as path from 'path';
+import * as os from 'os';
 
 async function run() {
   try {
     let version = core.getInput('python-version');
     if (version) {
-      const arch: string = core.getInput('architecture', {required: true});
+      const arch: string = core.getInput('architecture') || os.arch();
       const installed = await finder.findPythonVersion(version, arch);
       core.info(`Successfully setup ${installed.impl} (${installed.version})`);
     }