Merge pull request #127 from peter-evans/dev

Unset and restore extraheader config option

.eslintrc.json

@@ -0,0 +1,17 @@
+{
+    "env": {
+        "commonjs": true,
+        "es6": true,
+        "node": true
+    },
+    "extends": "eslint:recommended",
+    "globals": {
+        "Atomics": "readonly",
+        "SharedArrayBuffer": "readonly"
+    },
+    "parserOptions": {
+        "ecmaVersion": 2018
+    },
+    "rules": {
+    }
+}

README.md

@@ -18,7 +18,7 @@ Create Pull Request action will:
 
 ## Documentation
 
-- [Concepts and guidelines](docs/concepts-guidelines.md)
+- [Concepts, guidelines and advanced usage](docs/concepts-guidelines.md)
 - [Examples](docs/examples.md)
 - [Updating from v1](docs/updating.md)
 
@@ -37,8 +37,7 @@ You can also pin to a [specific release](https://github.com/peter-evans/create-p
 
 With the exception of `token`, all inputs are **optional**. If not set, sensible default values will be used.
 
-**Note**: If you want pull requests created by this action to trigger an `on: pull_request` workflow then you must use a [Personal Access Token](https://help.github.com/en/articles/creating-a-personal-access-token-for-the-command-line) instead of the default `GITHUB_TOKEN`.
-See [this issue](https://github.com/peter-evans/create-pull-request/issues/48) for further details.
+**Note**: If you want pull requests created by this action to trigger an `on: push` or `on: pull_request` workflow then you must use a [Personal Access Token](https://help.github.com/en/articles/creating-a-personal-access-token-for-the-command-line) instead of the default `GITHUB_TOKEN`. Alternatively, allow the action to [push using SSH](https://github.com/peter-evans/create-pull-request/blob/master/docs/concepts-guidelines.md#push-using-ssh-deploy-keys) by configuring a deploy key.
 
 | Name | Description | Default |
 | --- | --- | --- |
@@ -88,21 +87,6 @@ If there is some reason you need to use `actions/checkout@v1` the following step
       - run: git checkout "${GITHUB_REF:11}"
 ```
 
-Checking out a branch from a different repository from where the workflow is executing will make *that repository* the target for the created pull request. In this case, a `repo` scoped [Personal Access Token (PAT)](https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line) is required.
-
-```yml
-      - uses: actions/checkout@v2
-        with:
-          token: ${{ secrets.PAT }}
-          repository: owner/repo
-
-      # Create changes to pull request here
-
-      - uses: peter-evans/create-pull-request@v2
-        with:
-          token: ${{ secrets.PAT }}
-```
-
 ### Branch naming
 
 For branch naming there are two strategies. Create a fixed-name pull request branch that will be updated with new changes until it is merged or closed, OR, always create a new unique branch each time there are changes to be committed.

dist/cpr/create_pull_request.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 """ Create Pull Request """
+import base64
 import common as cmn
 import create_or_update_branch as coub
 import create_or_update_pull_request as coupr
@@ -31,7 +32,7 @@ def get_git_config_value(repo, name):
         return None
 
 
-def get_repository_detail():
+def get_repository_detail(repo):
     remote_origin_url = get_git_config_value(repo, "remote.origin.url")
     if remote_origin_url is None:
         raise ValueError("Failed to fetch 'remote.origin.url' from git config")
@@ -116,9 +117,21 @@ repo = Repo(path)
 
 # Determine the GitHub repository from git config
 # This will be the target repository for the pull request
-repo_url, protocol, github_repository = get_repository_detail()
+repo_url, protocol, github_repository = get_repository_detail(repo)
 print(f"Target repository set to {github_repository}")
 
+if protocol == "HTTPS":
+    print(f"::debug::Using HTTPS protocol")
+    # Encode and configure the basic credential for HTTPS access
+    basic_credential = base64.b64encode(
+        f"x-access-token:{github_token}".encode("utf-8")
+    ).decode("utf-8")
+    # Mask the basic credential in logs and debug output
+    print(f"::add-mask::{basic_credential}")
+    repo.git.set_persistent_git_options(
+        c=f"http.https://github.com/.extraheader=AUTHORIZATION: basic {basic_credential}"
+    )
+
 # Determine if the checked out ref is a valid base for a pull request
 # The action needs the checked out HEAD ref to be a branch
 # This check will fail in the following cases:
@@ -174,11 +187,6 @@ except ValueError as e:
     print(f"::error::{e} " + "Unable to continue. Exiting.")
     sys.exit(1)
 
-# Set the auth token in the repo URL
-# This supports checkout@v1. From v2 the auth token is saved for further use.
-if protocol == "HTTPS":
-    repo_url = f"https://x-access-token:{github_token}@github.com/{github_repository}"
-
 # Create or update the pull request branch
 result = coub.create_or_update_branch(repo, repo_url, commit_message, base, branch)
 

dist/cpr/requirements.txt

@@ -0,0 +1,2 @@
+GitPython==3.0.8
+PyGithub==1.46

dist/index.js

@@ -34,7 +34,7 @@ module.exports =
 /******/ 	// the startup function
 /******/ 	function startup() {
 /******/ 		// Load entry module and return exports
-/******/ 		return __webpack_require__(104);
+/******/ 		return __webpack_require__(676);
 /******/ 	};
 /******/
 /******/ 	// run startup
@@ -973,21 +973,6 @@ module.exports = util.assign(
 
 module.exports = require("tls");
 
-/***/ }),
-
-/***/ 58:
-/***/ (function(module, __unusedexports, __webpack_require__) {
-
-// Unique ID creation requires a high quality random # generator.  In node.js
-// this is pretty straight-forward - we use the crypto API.
-
-var crypto = __webpack_require__(417);
-
-module.exports = function nodeRNG() {
-  return crypto.randomBytes(16);
-};
-
-
 /***/ }),
 
 /***/ 87:
@@ -998,108 +983,6 @@ module.exports = require("os");
 /***/ }),
 
 /***/ 104:
-/***/ (function(__unusedmodule, __unusedexports, __webpack_require__) {
-
-const { inspect } = __webpack_require__(669);
-const fs = __webpack_require__(747);
-const core = __webpack_require__(470);
-const exec = __webpack_require__(986);
-const setupPython = __webpack_require__(139);
-
-function fileExists(path) {
-  try {
-    return fs.statSync(path).isFile();
-  } catch (e) {
-    core.debug(`e: ${inspect(e)}`);
-    return false;
-  }
-}
-
-async function run() {
-  try {
-    // Allows ncc to find assets to be included in the distribution
-    const src = __webpack_require__.ab + "src";
-    core.debug(`src: ${src}`);
-
-    // Check if the platfrom is Alpine Linux
-    const alpineLinux = fileExists("/etc/alpine-release");
-    core.debug(`alpineLinux: ${alpineLinux}`);
-
-    // Skip Python setup if the platform is Alpine Linux
-    if (!alpineLinux)
-      // Setup Python from the tool cache
-      setupPython("3.8.x", "x64");
-
-    // Install requirements
-    await exec.exec("pip", [
-      "install",
-      "--requirement",
-      `${src}/requirements.txt`,
-      "--no-index",
-      `--find-links=${__dirname}/vendor`
-    ]);
-
-    // Fetch action inputs
-    const inputs = {
-      token: core.getInput("token"),
-      path: core.getInput("path"),
-      commitMessage: core.getInput("commit-message"),
-      committer: core.getInput("committer"),
-      author: core.getInput("author"),
-      title: core.getInput("title"),
-      body: core.getInput("body"),
-      labels: core.getInput("labels"),
-      assignees: core.getInput("assignees"),
-      reviewers: core.getInput("reviewers"),
-      teamReviewers: core.getInput("team-reviewers"),
-      milestone: core.getInput("milestone"),
-      project: core.getInput("project"),
-      projectColumn: core.getInput("project-column"),
-      branch: core.getInput("branch"),
-      base: core.getInput("base"),
-      branchSuffix: core.getInput("branch-suffix"),
-    };
-    core.debug(`Inputs: ${inspect(inputs)}`);
-
-    // Set environment variables from inputs.
-    if (inputs.token) process.env.GITHUB_TOKEN = inputs.token;
-    if (inputs.path) process.env.CPR_PATH = inputs.path;
-    if (inputs.commitMessage) process.env.CPR_COMMIT_MESSAGE = inputs.commitMessage;
-    if (inputs.committer) process.env.CPR_COMMITTER = inputs.committer;
-    if (inputs.author) process.env.CPR_AUTHOR = inputs.author;
-    if (inputs.title) process.env.CPR_TITLE = inputs.title;
-    if (inputs.body) process.env.CPR_BODY = inputs.body;
-    if (inputs.labels) process.env.CPR_LABELS = inputs.labels;
-    if (inputs.assignees) process.env.CPR_ASSIGNEES = inputs.assignees;
-    if (inputs.reviewers) process.env.CPR_REVIEWERS = inputs.reviewers;
-    if (inputs.teamReviewers) process.env.CPR_TEAM_REVIEWERS = inputs.teamReviewers;
-    if (inputs.milestone) process.env.CPR_MILESTONE = inputs.milestone;
-    if (inputs.project) process.env.CPR_PROJECT_NAME = inputs.project;
-    if (inputs.projectColumn) process.env.CPR_PROJECT_COLUMN_NAME = inputs.projectColumn;
-    if (inputs.branch) process.env.CPR_BRANCH = inputs.branch;
-    if (inputs.base) process.env.CPR_BASE = inputs.base;
-    if (inputs.branchSuffix) process.env.CPR_BRANCH_SUFFIX = inputs.branchSuffix;
-
-    // Execute python script
-    await exec.exec("python", [`${src}/create_pull_request.py`]);
-  } catch (error) {
-    core.setFailed(error.message);
-  }
-}
-
-run();
-
-
-/***/ }),
-
-/***/ 129:
-/***/ (function(module) {
-
-module.exports = require("child_process");
-
-/***/ }),
-
-/***/ 139:
 /***/ (function(module, __unusedexports, __webpack_require__) {
 
 const core = __webpack_require__(470);
@@ -1156,6 +1039,28 @@ let setupPython = function(versionSpec, arch) {
 module.exports = setupPython;
 
 
+/***/ }),
+
+/***/ 129:
+/***/ (function(module) {
+
+module.exports = require("child_process");
+
+/***/ }),
+
+/***/ 139:
+/***/ (function(module, __unusedexports, __webpack_require__) {
+
+// Unique ID creation requires a high quality random # generator.  In node.js
+// this is pretty straight-forward - we use the crypto API.
+
+var crypto = __webpack_require__(417);
+
+module.exports = function nodeRNG() {
+  return crypto.randomBytes(16);
+};
+
+
 /***/ }),
 
 /***/ 141:
@@ -1411,6 +1316,43 @@ if (process.env.NODE_DEBUG && /\btunnel\b/.test(process.env.NODE_DEBUG)) {
 exports.debug = debug; // for test
 
 
+/***/ }),
+
+/***/ 160:
+/***/ (function(module, __unusedexports, __webpack_require__) {
+
+"use strict";
+
+const fs = __webpack_require__(747);
+
+let isDocker;
+
+function hasDockerEnv() {
+	try {
+		fs.statSync('/.dockerenv');
+		return true;
+	} catch (_) {
+		return false;
+	}
+}
+
+function hasDockerCGroup() {
+	try {
+		return fs.readFileSync('/proc/self/cgroup', 'utf8').includes('docker');
+	} catch (_) {
+		return false;
+	}
+}
+
+module.exports = () => {
+	if (isDocker === undefined) {
+		isDocker = hasDockerEnv() || hasDockerCGroup();
+	}
+
+	return isDocker;
+};
+
+
 /***/ }),
 
 /***/ 211:
@@ -4263,6 +4205,229 @@ function isUnixExecutable(stats) {
 }
 //# sourceMappingURL=io-util.js.map
 
+/***/ }),
+
+/***/ 676:
+/***/ (function(__unusedmodule, __unusedexports, __webpack_require__) {
+
+const { inspect } = __webpack_require__(669);
+const isDocker = __webpack_require__(160);
+const core = __webpack_require__(470);
+const exec = __webpack_require__(986);
+const setupPython = __webpack_require__(104);
+const {
+  getRepoPath,
+  getAndUnsetConfigOption,
+  addConfigOption
+} = __webpack_require__(718);
+
+const EXTRAHEADER_OPTION = "http.https://github.com/.extraheader";
+
+async function run() {
+  try {
+    // Allows ncc to find assets to be included in the distribution
+    const cpr = __webpack_require__.ab + "cpr";
+    core.debug(`cpr: ${cpr}`);
+
+    // Determine how to access python and pip
+    const { pip, python } = (function() {
+      if (isDocker()) {
+        core.info("Running inside a Docker container");
+        // Python 3 assumed to be installed and on the PATH
+        return {
+          pip: "pip3",
+          python: "python3"
+        };
+      } else {
+        // Setup Python from the tool cache
+        setupPython("3.x", "x64");
+        return {
+          pip: "pip",
+          python: "python"
+        };
+      }
+    })();
+
+    // Install requirements
+    await exec.exec(pip, [
+      "install",
+      "--requirement",
+      `${cpr}/requirements.txt`,
+      "--no-index",
+      `--find-links=${__dirname}/vendor`
+    ]);
+
+    // Fetch action inputs
+    const inputs = {
+      token: core.getInput("token"),
+      path: core.getInput("path"),
+      commitMessage: core.getInput("commit-message"),
+      committer: core.getInput("committer"),
+      author: core.getInput("author"),
+      title: core.getInput("title"),
+      body: core.getInput("body"),
+      labels: core.getInput("labels"),
+      assignees: core.getInput("assignees"),
+      reviewers: core.getInput("reviewers"),
+      teamReviewers: core.getInput("team-reviewers"),
+      milestone: core.getInput("milestone"),
+      project: core.getInput("project"),
+      projectColumn: core.getInput("project-column"),
+      branch: core.getInput("branch"),
+      base: core.getInput("base"),
+      branchSuffix: core.getInput("branch-suffix")
+    };
+    core.debug(`Inputs: ${inspect(inputs)}`);
+
+    // Set environment variables from inputs.
+    if (inputs.token) process.env.GITHUB_TOKEN = inputs.token;
+    if (inputs.path) process.env.CPR_PATH = inputs.path;
+    if (inputs.commitMessage) process.env.CPR_COMMIT_MESSAGE = inputs.commitMessage;
+    if (inputs.committer) process.env.CPR_COMMITTER = inputs.committer;
+    if (inputs.author) process.env.CPR_AUTHOR = inputs.author;
+    if (inputs.title) process.env.CPR_TITLE = inputs.title;
+    if (inputs.body) process.env.CPR_BODY = inputs.body;
+    if (inputs.labels) process.env.CPR_LABELS = inputs.labels;
+    if (inputs.assignees) process.env.CPR_ASSIGNEES = inputs.assignees;
+    if (inputs.reviewers) process.env.CPR_REVIEWERS = inputs.reviewers;
+    if (inputs.teamReviewers) process.env.CPR_TEAM_REVIEWERS = inputs.teamReviewers;
+    if (inputs.milestone) process.env.CPR_MILESTONE = inputs.milestone;
+    if (inputs.project) process.env.CPR_PROJECT_NAME = inputs.project;
+    if (inputs.projectColumn) process.env.CPR_PROJECT_COLUMN_NAME = inputs.projectColumn;
+    if (inputs.branch) process.env.CPR_BRANCH = inputs.branch;
+    if (inputs.base) process.env.CPR_BASE = inputs.base;
+    if (inputs.branchSuffix) process.env.CPR_BRANCH_SUFFIX = inputs.branchSuffix;
+
+    // Get the repository path
+    var repoPath = getRepoPath(inputs.path);
+    // Get the extraheader config option if it exists
+    var extraHeaderOptionValue = await getAndUnsetConfigOption(
+      repoPath,
+      EXTRAHEADER_OPTION
+    );
+
+    // Execute create pull request
+    await exec.exec(python, [`${cpr}/create_pull_request.py`]);
+  } catch (error) {
+    core.setFailed(error.message);
+  } finally {
+    // Restore the extraheader config option
+    if (extraHeaderOptionValue) {
+      if (
+        await addConfigOption(
+          repoPath,
+          EXTRAHEADER_OPTION,
+          extraHeaderOptionValue
+        )
+      )
+        core.debug(`Restored config option '${EXTRAHEADER_OPTION}'`);
+    }
+  }
+}
+
+run();
+
+
+/***/ }),
+
+/***/ 718:
+/***/ (function(module, __unusedexports, __webpack_require__) {
+
+const core = __webpack_require__(470);
+const exec = __webpack_require__(986);
+const path = __webpack_require__(622);
+
+function getRepoPath(relativePath) {
+  let githubWorkspacePath = process.env["GITHUB_WORKSPACE"];
+  if (!githubWorkspacePath) {
+    throw new Error("GITHUB_WORKSPACE not defined");
+  }
+  githubWorkspacePath = path.resolve(githubWorkspacePath);
+  core.debug(`githubWorkspacePath: ${githubWorkspacePath}`);
+
+  repoPath = githubWorkspacePath;
+  if (relativePath) repoPath = path.resolve(repoPath, relativePath);
+
+  core.debug(`repoPath: ${repoPath}`);
+  return repoPath;
+}
+
+async function execGit(repoPath, args, ignoreReturnCode = false) {
+  const stdout = [];
+  const options = {
+    cwd: repoPath,
+    ignoreReturnCode: ignoreReturnCode,
+    listeners: {
+      stdout: data => {
+        stdout.push(data.toString());
+      }
+    }
+  };
+
+  var result = {};
+  result.exitCode = await exec.exec("git", args, options);
+  result.stdout = stdout.join("");
+  return result;
+}
+
+async function addConfigOption(repoPath, name, value) {
+  const result = await execGit(
+    repoPath,
+    ["config", "--local", "--add", name, value],
+    true
+  );
+  return result.exitCode === 0;
+}
+
+async function unsetConfigOption(repoPath, name) {
+  const result = await execGit(
+    repoPath,
+    ["config", "--local", "--unset", name],
+    true
+  );
+  return result.exitCode === 0;
+}
+
+async function configOptionExists(repoPath, name) {
+  const result = await execGit(
+    repoPath,
+    ["config", "--local", "--name-only", "--get-regexp", name],
+    true
+  );
+  return result.exitCode === 0;
+}
+
+async function getConfigOption(repoPath, name) {
+  const result = await execGit(
+    repoPath,
+    ["config", "--local", name],
+    true
+  );
+  return result.stdout.trim();
+}
+
+async function getAndUnsetConfigOption(repoPath, name) {
+  if (await configOptionExists(repoPath, name)) {
+    const extraHeaderOptionValue = await getConfigOption(repoPath, name);
+    if (await unsetConfigOption(repoPath, name)) {
+      core.debug(`Unset config option '${name}'`);
+      return extraHeaderOptionValue;
+    }
+  }
+  return null;
+}
+
+module.exports = {
+  getRepoPath,
+  execGit,
+  addConfigOption,
+  unsetConfigOption,
+  configOptionExists,
+  getConfigOption,
+  getAndUnsetConfigOption
+};
+
+
 /***/ }),
 
 /***/ 722:
@@ -4695,7 +4860,7 @@ module.exports = require("zlib");
 /***/ 826:
 /***/ (function(module, __unusedexports, __webpack_require__) {
 
-var rng = __webpack_require__(58);
+var rng = __webpack_require__(139);
 var bytesToUuid = __webpack_require__(722);
 
 function v4(options, buf, offset) {

dist/src/requirements.txt

@@ -1,2 +0,0 @@
-GitPython==3.0.7
-PyGithub==1.45

dist/src/setup-python.js

@@ -1,52 +0,0 @@
-const core = require("@actions/core");
-const tc = require("@actions/tool-cache");
-const path = require("path");
-const semver = require("semver");
-
-/**
- * Setup for Python from the GitHub Actions tool cache
- * Converted from https://github.com/actions/setup-python
- *
- * @param {string} versionSpec version of Python
- * @param {string} arch architecture (x64|x32)
- */
-let setupPython = function(versionSpec, arch) {
-  return new Promise((resolve, reject) => {
-    const IS_WINDOWS = process.platform === "win32";
-
-    // Find the version of Python we want in the tool cache
-    const installDir = tc.find("Python", versionSpec, arch);
-    core.debug(`installDir: ${installDir}`);
-
-    // Set paths
-    core.exportVariable("pythonLocation", installDir);
-    core.addPath(installDir);
-    if (IS_WINDOWS) {
-      core.addPath(path.join(installDir, "Scripts"));
-    } else {
-      core.addPath(path.join(installDir, "bin"));
-    }
-
-    if (IS_WINDOWS) {
-      // Add --user directory
-      // `installDir` from tool cache should look like $AGENT_TOOLSDIRECTORY/Python/<semantic version>/x64/
-      // So if `findLocalTool` succeeded above, we must have a conformant `installDir`
-      const version = path.basename(path.dirname(installDir));
-      const major = semver.major(version);
-      const minor = semver.minor(version);
-
-      const userScriptsDir = path.join(
-        process.env["APPDATA"] || "",
-        "Python",
-        `Python${major}${minor}`,
-        "Scripts"
-      );
-      core.addPath(userScriptsDir);
-    }
-    // On Linux and macOS, pip will create the --user directory and add it to PATH as needed.
-
-    resolve();
-  });
-};
-
-module.exports = setupPython;

docs/concepts-guidelines.md

@@ -1,6 +1,6 @@
-# Concepts and guidelines
+# Concepts, guidelines and advanced usage
 
-This document covers terminology, how the action works, and general usage guidelines.
+This document covers terminology, how the action works, general usage guidelines, and advanced usage.
 
 - [Terminology](#terminology)
 - [Events and checkout](#events-and-checkout)
@@ -9,8 +9,12 @@ This document covers terminology, how the action works, and general usage guidel
   - [Providing a consistent base](#providing-a-consistent-base)
   - [Pull request events](#pull-request-events)
   - [Restrictions on forked repositories](#restrictions-on-forked-repositories)
-  - [Tag push events](#tag-push-events)
   - [Security](#security)
+- [Advanced usage](#advanced-usage)
+  - [Creating pull requests in a remote repository](#creating-pull-requests-in-a-remote-repository)
+  - [Push using SSH (deploy keys)](#push-using-ssh-deploy-keys)
+  - [Running in a container](#running-in-a-container)
+  - [Creating pull requests on tag push](#creating-pull-requests-on-tag-push)
 
 ## Terminology
 
@@ -108,7 +112,129 @@ jobs:
     if: github.event.pull_request.head.repo.full_name == github.repository
 ```
 
-### Tag push events
+### Security
+
+From a security perspective it's good practice to fork third-party actions, review the code, and use your fork of the action in workflows.
+By using third-party actions directly the risk exists that it could be modified to do something malicious, such as capturing secrets.
+
+This action uses [ncc](https://github.com/zeit/ncc) to compile the Node.js code and dependencies into a single file.
+Python dependencies are vendored and committed to the repository [here](https://github.com/peter-evans/create-pull-request/tree/master/dist/vendor).
+No dependencies are downloaded during the action execution.
+
+Vendored Python dependencies can be reviewed by rebuilding the [dist](https://github.com/peter-evans/create-pull-request/tree/master/dist) directory and redownloading dependencies.
+The following commands require Node and Python 3.
+
+```
+npm install
+npm run clean
+npm run package
+```
+
+The `dist` directory should be rebuilt leaving no git diff.
+
+## Advanced usage
+
+### Creating pull requests in a remote repository
+
+Checking out a branch from a different repository from where the workflow is executing will make *that repository* the target for the created pull request. In this case, a `repo` scoped [Personal Access Token (PAT)](https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line) is required.
+
+```yml
+      - uses: actions/checkout@v2
+        with:
+          token: ${{ secrets.PAT }}
+          repository: owner/repo
+
+      # Make changes to pull request here
+
+      - uses: peter-evans/create-pull-request@v2
+        with:
+          token: ${{ secrets.PAT }}
+```
+
+### Push using SSH (deploy keys)
+
+[Deploy keys](https://developer.github.com/v3/guides/managing-deploy-keys/#deploy-keys) can be set per repository and so are arguably more secure than using a `repo` scoped [Personal Access Token (PAT)](https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line).
+Allowing the action to push with a configured deploy key will trigger `on: push` workflows. This makes it an alternative to using a PAT to trigger checks for pull requests.
+
+How to use SSH (deploy keys) with create-pull-request action:
+
+1. [Create a new SSH key pair](https://help.github.com/en/github/authenticating-to-github/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent#generating-a-new-ssh-key) for your repository. Do not set a passphrase.
+2. Copy the contents of the public key (.pub file) to a new repository [deploy key](https://developer.github.com/v3/guides/managing-deploy-keys/#deploy-keys) and check the box to "Allow write access."
+3. Add a secret to the repository containing the entire contents of the private key.
+4. As shown in the example steps below, use the [`webfactory/ssh-agent`](https://github.com/webfactory/ssh-agent) action to install the private key and clone your repository. Remember to checkout the `base` of your pull request if it's not the default branch, e.g. `git checkout my-branch`.
+
+```yml
+    steps:
+      - uses: webfactory/ssh-agent@v0.2.0
+        with:
+          ssh-private-key: ${{ secrets.SSH_PRIVATE_KEY }}
+
+      - name: Checkout via SSH
+        run: git clone git@github.com:peter-evans/create-pull-request.git .
+
+      # Make changes to pull request here
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+```
+
+### Running in a container
+
+This action can be run inside a container by installing the action's dependencies either in the Docker image itself, or during the workflow.
+
+The action requires `python3`, `pip3` and `git` to be installed and on the `PATH`.
+
+Note that `actions/checkout` requires Git 2.18 or higher to be installed, otherwise it will just download the source of the repository instead of cloning it.
+
+**Alpine container example:**
+```yml
+jobs:
+  createPullRequestAlpine:
+    runs-on: ubuntu-latest
+    container:
+      image: alpine
+    steps:
+      - name: Install dependencies
+        run: apk --no-cache add git python3
+
+      - uses: actions/checkout@v2
+
+      # Make changes to pull request here
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+```
+
+**Ubuntu container example:**
+```yml
+jobs:
+  createPullRequestAlpine:
+    runs-on: ubuntu-latest
+    container:
+      image: ubuntu
+    steps:
+      - name: Install dependencies
+        run: |
+          apt-get update
+          apt-get install -y software-properties-common
+          add-apt-repository -y ppa:git-core/ppa
+          apt-get install -y python3 python3-pip git
+
+      - uses: actions/checkout@v2
+
+      # Make changes to pull request here
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+```
+
+### Creating pull requests on tag push
 
 An `on: push` workflow will also trigger when tags are pushed.
 During these events, the `actions/checkout` action will check out the `ref/tags/<tag>` git ref by default.
@@ -134,8 +260,7 @@ jobs:
           git checkout -b temp-${GITHUB_REF:10}
           git push --set-upstream origin temp-${GITHUB_REF:10}
 
-      - name: Create changes to pull request
-        run: <create changes here>
+      # Make changes to pull request here
 
       - name: Create Pull Request
         uses: peter-evans/create-pull-request@v2
@@ -164,31 +289,10 @@ jobs:
         with:
           ref: master
 
-      - name: Create changes to pull request
-        run: <create changes here>
+      # Make changes to pull request here
 
       - name: Create Pull Request
         uses: peter-evans/create-pull-request@v2
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
 ```
-
-### Security
-
-From a security perspective it's good practice to fork third-party actions, review the code, and use your fork of the action in workflows.
-By using third-party actions directly the risk exists that it could be modified to do something malicious, such as capturing secrets.
-
-This action uses [ncc](https://github.com/zeit/ncc) to compile the Node.js code and dependencies into a single file.
-Python dependencies are vendored and committed to the repository [here](https://github.com/peter-evans/create-pull-request/tree/master/dist/vendor).
-No dependencies are downloaded during the action execution.
-
-Vendored Python dependencies can be reviewed by rebuilding the [dist](https://github.com/peter-evans/create-pull-request/tree/master/dist) directory and redownloading dependencies.
-The following commands require Node and Python 3.
-
-```
-npm install
-npm run clean
-npm run package
-```
-
-The `dist` directory should be rebuilt leaving no git diff.

docs/examples.md

@@ -2,6 +2,7 @@
 
 - [Use case: Create a pull request to update X on push](#use-case-create-a-pull-request-to-update-x-on-push)
   - [Update project authors](#update-project-authors)
+  - [Keep a branch up-to-date with another](#keep-a-branch-up-to-date-with-another)
 - [Use case: Create a pull request to update X periodically](#use-case-create-a-pull-request-to-update-x-periodically)
   - [Update NPM dependencies](#update-npm-dependencies)
   - [Update SwaggerUI for GitHub Pages](#update-swaggerui-for-github-pages)
@@ -51,6 +52,36 @@ jobs:
           branch: update-authors
 ```
 
+### Keep a branch up-to-date with another
+
+This is a use case where a branch should be kept up to date with another by opening a pull request to update it. The pull request should then be updated with new changes until it is merged or closed.
+
+In this example scenario, a branch called `production` should be updated via pull request to keep it in sync with `master`. Merging the pull request is effectively promoting those changes to production.
+
+```yml
+name: Create production promotion pull request
+on:
+  push:
+    branches:
+      - master
+jobs:
+  productionPromotion:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          ref: production
+      - name: Reset promotion branch
+        run: |
+          git fetch origin master:master
+          git reset --hard master
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          branch: production-promotion
+```
+
 ## Use case: Create a pull request to update X periodically
 
 This pattern will work well for updating any kind of static content from an external source. The workflow executes on a schedule and raises a pull request when there are changes.

jest.config.js

@@ -0,0 +1,3 @@
+process.env = Object.assign(process.env, {
+  GITHUB_WORKSPACE: __dirname
+});

package.json

@@ -5,8 +5,10 @@
   "main": "index.js",
   "scripts": {
     "clean": "rm -rf dist",
-    "build": "ncc build index.js -o dist",
-    "vendor-deps": "pip download -r src/requirements.txt --no-binary=:all: -d dist/vendor",
+    "lint": "eslint src/index.js",
+    "test": "eslint src/index.js && jest",
+    "build": "ncc build src/index.js -o dist",
+    "vendor-deps": "pip download -r src/cpr/requirements.txt --no-binary=:all: -d dist/vendor",
     "package": "npm run build && npm run vendor-deps"
   },
   "repository": {
@@ -23,9 +25,12 @@
   "dependencies": {
     "@actions/core": "^1.1.1",
     "@actions/exec": "^1.0.1",
-    "@actions/tool-cache": "^1.1.2"
+    "@actions/tool-cache": "^1.1.2",
+    "is-docker": "^2.0.0"
   },
   "devDependencies": {
-    "@zeit/ncc": "0.21.0"
+    "@zeit/ncc": "0.21.1",
+    "eslint": "6.8.0",
+    "jest": "25.1.0"
   }
 }

src/cpr/create_pull_request.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 """ Create Pull Request """
+import base64
 import common as cmn
 import create_or_update_branch as coub
 import create_or_update_pull_request as coupr
@@ -31,7 +32,7 @@ def get_git_config_value(repo, name):
         return None
 
 
-def get_repository_detail():
+def get_repository_detail(repo):
     remote_origin_url = get_git_config_value(repo, "remote.origin.url")
     if remote_origin_url is None:
         raise ValueError("Failed to fetch 'remote.origin.url' from git config")
@@ -116,9 +117,21 @@ repo = Repo(path)
 
 # Determine the GitHub repository from git config
 # This will be the target repository for the pull request
-repo_url, protocol, github_repository = get_repository_detail()
+repo_url, protocol, github_repository = get_repository_detail(repo)
 print(f"Target repository set to {github_repository}")
 
+if protocol == "HTTPS":
+    print(f"::debug::Using HTTPS protocol")
+    # Encode and configure the basic credential for HTTPS access
+    basic_credential = base64.b64encode(
+        f"x-access-token:{github_token}".encode("utf-8")
+    ).decode("utf-8")
+    # Mask the basic credential in logs and debug output
+    print(f"::add-mask::{basic_credential}")
+    repo.git.set_persistent_git_options(
+        c=f"http.https://github.com/.extraheader=AUTHORIZATION: basic {basic_credential}"
+    )
+
 # Determine if the checked out ref is a valid base for a pull request
 # The action needs the checked out HEAD ref to be a branch
 # This check will fail in the following cases:
@@ -174,11 +187,6 @@ except ValueError as e:
     print(f"::error::{e} " + "Unable to continue. Exiting.")
     sys.exit(1)
 
-# Set the auth token in the repo URL
-# This supports checkout@v1. From v2 the auth token is saved for further use.
-if protocol == "HTTPS":
-    repo_url = f"https://x-access-token:{github_token}@github.com/{github_repository}"
-
 # Create or update the pull request branch
 result = coub.create_or_update_branch(repo, repo_url, commit_message, base, branch)
 

src/cpr/requirements.txt

@@ -0,0 +1,2 @@
+GitPython==3.0.8
+PyGithub==1.46

src/git.js

@@ -0,0 +1,93 @@
+const core = require("@actions/core");
+const exec = require("@actions/exec");
+const path = require("path");
+
+function getRepoPath(relativePath) {
+  let githubWorkspacePath = process.env["GITHUB_WORKSPACE"];
+  if (!githubWorkspacePath) {
+    throw new Error("GITHUB_WORKSPACE not defined");
+  }
+  githubWorkspacePath = path.resolve(githubWorkspacePath);
+  core.debug(`githubWorkspacePath: ${githubWorkspacePath}`);
+
+  repoPath = githubWorkspacePath;
+  if (relativePath) repoPath = path.resolve(repoPath, relativePath);
+
+  core.debug(`repoPath: ${repoPath}`);
+  return repoPath;
+}
+
+async function execGit(repoPath, args, ignoreReturnCode = false) {
+  const stdout = [];
+  const options = {
+    cwd: repoPath,
+    ignoreReturnCode: ignoreReturnCode,
+    listeners: {
+      stdout: data => {
+        stdout.push(data.toString());
+      }
+    }
+  };
+
+  var result = {};
+  result.exitCode = await exec.exec("git", args, options);
+  result.stdout = stdout.join("");
+  return result;
+}
+
+async function addConfigOption(repoPath, name, value) {
+  const result = await execGit(
+    repoPath,
+    ["config", "--local", "--add", name, value],
+    true
+  );
+  return result.exitCode === 0;
+}
+
+async function unsetConfigOption(repoPath, name) {
+  const result = await execGit(
+    repoPath,
+    ["config", "--local", "--unset", name],
+    true
+  );
+  return result.exitCode === 0;
+}
+
+async function configOptionExists(repoPath, name) {
+  const result = await execGit(
+    repoPath,
+    ["config", "--local", "--name-only", "--get-regexp", name],
+    true
+  );
+  return result.exitCode === 0;
+}
+
+async function getConfigOption(repoPath, name) {
+  const result = await execGit(
+    repoPath,
+    ["config", "--local", name],
+    true
+  );
+  return result.stdout.trim();
+}
+
+async function getAndUnsetConfigOption(repoPath, name) {
+  if (await configOptionExists(repoPath, name)) {
+    const extraHeaderOptionValue = await getConfigOption(repoPath, name);
+    if (await unsetConfigOption(repoPath, name)) {
+      core.debug(`Unset config option '${name}'`);
+      return extraHeaderOptionValue;
+    }
+  }
+  return null;
+}
+
+module.exports = {
+  getRepoPath,
+  execGit,
+  addConfigOption,
+  unsetConfigOption,
+  configOptionExists,
+  getConfigOption,
+  getAndUnsetConfigOption
+};

src/git.test.js

@@ -0,0 +1,72 @@
+const path = require("path");
+const {
+  getRepoPath,
+  execGit,
+  addConfigOption,
+  unsetConfigOption,
+  configOptionExists,
+  getConfigOption,
+  getAndUnsetConfigOption
+} = require("./git");
+
+test("getRepoPath", async () => {
+  expect(getRepoPath()).toEqual(process.env["GITHUB_WORKSPACE"]);
+  expect(getRepoPath("foo")).toEqual(
+    path.resolve(process.env["GITHUB_WORKSPACE"], "foo")
+  );
+});
+
+test("execGit", async () => {
+  const repoPath = getRepoPath();
+  const result = await execGit(
+    repoPath,
+    ["config", "--local", "--name-only", "--get-regexp", "remote.origin.url"],
+    true
+  );
+  expect(result.exitCode).toEqual(0);
+  expect(result.stdout.trim()).toEqual("remote.origin.url");
+});
+
+test("add and unset config option", async () => {
+  const repoPath = getRepoPath();
+  const add = await addConfigOption(repoPath, "test.add.and.unset.config.option", "true");
+  expect(add).toBeTruthy();
+  const unset = await unsetConfigOption(repoPath, "test.add.and.unset.config.option");
+  expect(unset).toBeTruthy();
+});
+
+test("configOptionExists returns true", async () => {
+  const repoPath = getRepoPath();
+  const result = await configOptionExists(repoPath, "remote.origin.url");
+  expect(result).toBeTruthy();
+});
+
+test("configOptionExists returns false", async () => {
+  const repoPath = getRepoPath();
+  const result = await configOptionExists(repoPath, "this.key.does.not.exist");
+  expect(result).toBeFalsy();
+});
+
+test("get config option", async () => {
+  const repoPath = getRepoPath();
+  const add = await addConfigOption(repoPath, "test.get.config.option", "foo");
+  expect(add).toBeTruthy();
+  const get = await getConfigOption(repoPath, "test.get.config.option");
+  expect(get).toEqual("foo");
+  const unset = await unsetConfigOption(repoPath, "test.get.config.option");
+  expect(unset).toBeTruthy();
+});
+
+test("get and unset config option is successful", async () => {
+  const repoPath = getRepoPath();
+  const add = await addConfigOption(repoPath, "test.get.and.unset.config.option", "foo");
+  expect(add).toBeTruthy();
+  const getAndUnset = await getAndUnsetConfigOption(repoPath, "test.get.and.unset.config.option");
+  expect(getAndUnset).toEqual("foo");
+});
+
+test("get and unset config option is unsuccessful", async () => {
+  const repoPath = getRepoPath();
+  const getAndUnset = await getAndUnsetConfigOption(repoPath, "this.key.does.not.exist");
+  expect(getAndUnset).toBeNull();
+});

src/index.js

@@ -1,38 +1,46 @@
 const { inspect } = require("util");
-const fs = require("fs");
+const isDocker = require("is-docker");
 const core = require("@actions/core");
 const exec = require("@actions/exec");
-const setupPython = require("./src/setup-python");
+const setupPython = require("./setup-python");
+const {
+  getRepoPath,
+  getAndUnsetConfigOption,
+  addConfigOption
+} = require("./git");
 
-function fileExists(path) {
-  try {
-    return fs.statSync(path).isFile();
-  } catch (e) {
-    core.debug(`e: ${inspect(e)}`);
-    return false;
-  }
-}
+const EXTRAHEADER_OPTION = "http.https://github.com/.extraheader";
 
 async function run() {
   try {
     // Allows ncc to find assets to be included in the distribution
-    const src = __dirname + "/src";
-    core.debug(`src: ${src}`);
+    const cpr = __dirname + "/cpr";
+    core.debug(`cpr: ${cpr}`);
 
-    // Check if the platfrom is Alpine Linux
-    const alpineLinux = fileExists("/etc/alpine-release");
-    core.debug(`alpineLinux: ${alpineLinux}`);
-
-    // Skip Python setup if the platform is Alpine Linux
-    if (!alpineLinux)
-      // Setup Python from the tool cache
-      setupPython("3.8.x", "x64");
+    // Determine how to access python and pip
+    const { pip, python } = (function() {
+      if (isDocker()) {
+        core.info("Running inside a Docker container");
+        // Python 3 assumed to be installed and on the PATH
+        return {
+          pip: "pip3",
+          python: "python3"
+        };
+      } else {
+        // Setup Python from the tool cache
+        setupPython("3.x", "x64");
+        return {
+          pip: "pip",
+          python: "python"
+        };
+      }
+    })();
 
     // Install requirements
-    await exec.exec("pip", [
+    await exec.exec(pip, [
       "install",
       "--requirement",
-      `${src}/requirements.txt`,
+      `${cpr}/requirements.txt`,
       "--no-index",
       `--find-links=${__dirname}/vendor`
     ]);
@@ -55,7 +63,7 @@ async function run() {
       projectColumn: core.getInput("project-column"),
       branch: core.getInput("branch"),
       base: core.getInput("base"),
-      branchSuffix: core.getInput("branch-suffix"),
+      branchSuffix: core.getInput("branch-suffix")
     };
     core.debug(`Inputs: ${inspect(inputs)}`);
 
@@ -78,10 +86,30 @@ async function run() {
     if (inputs.base) process.env.CPR_BASE = inputs.base;
     if (inputs.branchSuffix) process.env.CPR_BRANCH_SUFFIX = inputs.branchSuffix;
 
-    // Execute python script
-    await exec.exec("python", [`${src}/create_pull_request.py`]);
+    // Get the repository path
+    var repoPath = getRepoPath(inputs.path);
+    // Get the extraheader config option if it exists
+    var extraHeaderOptionValue = await getAndUnsetConfigOption(
+      repoPath,
+      EXTRAHEADER_OPTION
+    );
+
+    // Execute create pull request
+    await exec.exec(python, [`${cpr}/create_pull_request.py`]);
   } catch (error) {
     core.setFailed(error.message);
+  } finally {
+    // Restore the extraheader config option
+    if (extraHeaderOptionValue) {
+      if (
+        await addConfigOption(
+          repoPath,
+          EXTRAHEADER_OPTION,
+          extraHeaderOptionValue
+        )
+      )
+        core.debug(`Restored config option '${EXTRAHEADER_OPTION}'`);
+    }
   }
 }
 

src/requirements.txt

@@ -1,2 +0,0 @@
-GitPython==3.0.7
-PyGithub==1.45