Platform.sh Activity Script - Hook on Code Push event to trigger Github Action with Github Source Branch

trigger_cypress_testing.js

/**
 * This activity script gets
 *  the URL of the new environment from PSH,
 *  then requests the originating branch from the Github API (Github is largely unaware of PR branches it seems)
 *  then triggers a Github Action to build a linux container that runs cypress tests against the PR environment
 */

const ghUser = 'github user that owns the repo'; // found in the url e.g. github.com/ghUser/ghRepo
const ghRepo = 'repo name';

try {
  // be sure it's a real deployment
  if (typeof activity.payload.deployment === "undefined") {
    console.log(
      "Deployment payload (and therefore Variables) is unavailable in this state: " +
        activity.state
    );
    throw new Error("No deployment payload");
  }
  // get any variables necessary
  var githubToken = variables()["GITHUB_AUTH"];

  // verify the run was successful and environment is active
  if (
    activity.result !== "success" ||
    activity.payload.environment.status !== "active" ||
    !githubToken
  ) {
    console.log("A fatal error has occurred");
    console.log("Activity Result", activity.result);
    console.log("Activity Env Status", activity.payload.environment.status);
    console.log("Github token length", githubToken.length);
    throw new Error("Fatal Error");
  }

  // get the URL of the environment (dynamic)
  var routes = activity.payload.deployment.routes;
  var route = Object.keys(activity.payload.deployment.routes).reduce(function (
    accumulator,
    key
  ) {
    return routes[key].primary ? key : accumulator;
  },
  routes[0] || false);

  if (!route) {
    throw new Error(`No route provided: ${routes}`);
  }

  // PULL REQUESTS
  // get the original branch from the pull request
  getOriginalBranchName(
    activity.payload.environment.name.split("-")[1],
    githubToken,
    function (err, ref) {
      if (err) {
        console.log("error getting branch", err);
        throw new Error(err);
      }
      // trigger the github action script
      console.log("ref", ref);
      trigger_github_action(route, ref, githubToken);
    }
  );
} catch (exception) {
  console.log("An exception has been thrown: " + exception);
}

/**
 *
 * @param {string} pullRequest The number of the pull request (e.g. 233)
 * @param {string} githubToken Your personal Github Token
 * @param {function} cb A function with the arguments (err, ref) - use this to access results.
 */
function getOriginalBranchName(pullRequest, githubToken, cb) {
  var requestOptions = {
    method: "GET",
    headers: {
      Accept: "application/vnd.github.v3+json",
      Authorization: `Bearer ${githubToken}`,
      "Content-Type": "application/json",
    },
    redirect: "follow",
  };
  var response = fetch(
    `https://api.github.com/repos/${ghUser}/${ghRepo}/pulls/${pullRequest}`,
    requestOptions
  );
  if (!response.ok) {
    console.log(
      "Request to Github Pull Request API Failed",
      response.body.text()
    );
    cb("Failed to contact Github API");
  } else {
    var responseJson = response.json();
    var responseJsonStr = JSON.stringify(responseJson);
    var responseJsonParsed = JSON.parse(JSON.stringify(responseJson));
    if (responseJson) {
      cb(null, responseJsonParsed.head.ref);
    } else {
      cb("could not find remote ref");
    }
  }
}

/**
 *
 * @param {string} baseUrl The base URL created by Platform.sh
 * @param {string} branchName The branch name that created the Pull Request
 * @param {string} githubToken Your personal Github Token
 */
function trigger_github_action(baseUrl, branchName, githubToken) {
  var requestOptions = {
    method: "POST",
    headers: {
      Accept: "application/vnd.github.v3+json",
      Authorization: `Bearer ${githubToken}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      ref: branchName,
      inputs: {
        baseUrl: baseUrl,
      },
    }),
    redirect: "follow",
  };

  var response = fetch(
    `https://api.github.com/repos/${ghUser}/${ghRepo}/actions/workflows/cypress.yml/dispatches`,
    requestOptions
  );

  if (!response.ok) {
    console.log("Request to Github Actions API Failed", response.body.text());
  } else {
    console.log("Request to Github Actions API Succeeded");
    // this returns a 204 with no content
  }
}

/**
 * A simple function to parse the environment variables. This reads them exactly as they are created in the PSH UI.
 * e.g. if you need env:TOKEN you need to ask for variables()['env:TOKEN'] explicitly.
 */
function variables() {
  var vars = {};
  activity.payload.deployment.variables.forEach(function (variable) {
    vars[variable.name] = variable.value;
  });

  return vars;
}