Prod deployment workflow (#21223)

* add production deployment

* updating existing build

* remove state

* remove PR_URL and switch to main branch

* break out into build, prepare, and deploy

* update to download-artifact

* update staging to prod

* Actions production deployment redux (#21238)

* Simplify production deployment into a single Actions job

* Force esm to install

* Switch flag ordering to match staging deploy

* Use 'npm install' for the second installation to avoid deleting the prodDeps

* Apply Heroku upload fixes

* Include `.npmrc` file in builds to omit `optionalDeps`

* Remove download-artifact action

Co-authored-by: Grace Park <gracepark@github.com>

* Script updates to prod deployment (#21247)

* updating script to use latest sha

* changing back workflowRunLog

* remove line

* update error wording

* remove comment - using commit sha

* need release.id

* Update script/deployment/deploy-to-production.js

Co-authored-by: James M. Greene <JamesMGreene@github.com>

* remove hydro

* Update script/deployment/deploy-to-production.js

Co-authored-by: James M. Greene <JamesMGreene@github.com>

* Update .github/workflows/prod-build-deploy-pr.yml

Co-authored-by: James M. Greene <JamesMGreene@github.com>

* Update script/deployment/deploy-to-production.js

Co-authored-by: James M. Greene <JamesMGreene@github.com>

* Update script/deployment/deploy-to-production.js

Co-authored-by: James M. Greene <JamesMGreene@github.com>

* Update script/deployment/deploy-to-production.js

Co-authored-by: James M. Greene <JamesMGreene@github.com>

* updating spacing

* add 404/429 responses while polling Heroku API for prod

* removing nested ifs

* adding SOURCE_BLOB_URL

* update for early access

* add install dotenv

* need to add persist-credentials

* Testing GET request

* update request

* Rename workflow file to remove '-pr'

We are now triggering on pushes to 'main' rather than PR merges

* Remove the unnecessary workflow step to create a failure Status

Because the production deploy is done via a single workflow rather than a 2-part workflow chain, this is thankfully unnecessary

* Install all of the npm dependencies

We'll need them!

* Add the '-z' flag to 'tar' to gzip the tarball

* Pass the Heroku upload URL via env vars for security

Prevents potential injection attacks

* Log the deployment ID and log URL as deploy step outputs

* Take notice of Heroku polling resulting in failure statuses

* Add a note to consider waiting for Heroku Preboot

* Add a script and workflow step to purge Fastly

* update response to get sha

* Switch to Octokit functions instead of 'request' method

Co-authored-by: James M. Greene <JamesMGreene@github.com>

.github/workflows/prod-build-deploy.yml

@@ -0,0 +1,229 @@
+name: Production - Build and Deploy
+
+# **What it does**: Builds and deploys the default branch to production
+# **Why we have it**: To enable us to deploy the latest to production whenever necessary rather than relying on PR merges.
+# **Who does it impact**: All contributors.
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build-and-deploy:
+    if: ${{ github.repository == 'github/docs-internal'}}
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    concurrency:
+      group: prod_deploy
+      cancel-in-progress: true
+    steps:
+      - name: Check out repo
+        uses: actions/checkout@5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f
+        with:
+          persist-credentials: 'false'
+
+      - name: Setup node
+        uses: actions/setup-node@38d90ce44d5275ad62cc48384b3d8a58c500bb5f
+        with:
+          node-version: 16.8.x
+          cache: npm
+
+      # Required for `npm pkg ...` command support
+      - name: Update to npm@^7.20.0
+        run: npm install --global npm@^7.20.0
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Clone early access
+        run: node script/early-access/clone-for-build.js
+        env:
+          DOCUBOT_REPO_PAT: ${{ secrets.DOCUBOT_REPO_PAT }}
+          GIT_BRANCH: main
+
+      - name: Build
+        run: npm run build
+
+      - name: Remove development-only dependencies
+        run: npm prune --production
+
+      - name: Remove all npm scripts
+        run: npm pkg delete scripts
+
+      - name: Set npm script for Heroku build to noop
+        run: npm set-script heroku-postbuild "echo 'Application was pre-built!'"
+
+      - name: Create a gzipped archive
+        run: |
+          tar -cz --file=app.tar.gz \
+            node_modules/ \
+            .next/ \
+            assets/ \
+            content/ \
+            data/ \
+            includes/ \
+            lib/ \
+            middleware/ \
+            translations/ \
+            server.mjs \
+            package*.json \
+            .npmrc \
+            feature-flags.json \
+            next.config.js \
+            app.json \
+            Procfile
+
+      - name: Install the development dependencies again
+        run: npm install
+
+      - name: Create a Heroku build source
+        id: build-source
+        uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
+        env:
+          HEROKU_API_TOKEN: ${{ secrets.HEROKU_API_TOKEN }}
+        with:
+          script: |
+            const { owner, repo } = context.repo
+
+            if (owner !== 'github') {
+              throw new Error(`Repository owner must be 'github' but was: ${owner}`)
+            }
+            if (repo !== 'docs-internal') {
+              throw new Error(`Repository name must be 'docs-internal' but was: ${repo}`)
+            }
+
+            const Heroku = require('heroku-client')
+            const heroku = new Heroku({ token: process.env.HEROKU_API_TOKEN })
+
+            const { source_blob: sourceBlob } = await heroku.post('/sources')
+            const { put_url: uploadUrl, get_url: downloadUrl } = sourceBlob
+
+            core.setOutput('upload_url', uploadUrl)
+            core.setOutput('download_url', downloadUrl)
+
+      # See: https://devcenter.heroku.com/articles/build-and-release-using-the-api#sources-endpoint
+      - name: Upload to the Heroku build source
+        env:
+          UPLOAD_URL: ${{ steps.build-source.outputs.upload_url }}
+        run: |
+          curl "$UPLOAD_URL" \
+            -X PUT \
+            -H 'Content-Type:' \
+            --data-binary @app.tar.gz
+
+      - name: Install one-off development-only dependencies
+        run: npm install --no-save --include=optional esm
+
+      - name: Deploy
+        id: deploy
+        uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          HEROKU_API_TOKEN: ${{ secrets.HEROKU_API_TOKEN }}
+          HYDRO_ENDPOINT: ${{ secrets.HYDRO_ENDPOINT }}
+          HYDRO_SECRET: ${{ secrets.HYDRO_SECRET }}
+          SOURCE_BLOB_URL: ${{ steps.build-source.outputs.download_url }}
+        with:
+          script: |
+            const { GITHUB_TOKEN, HEROKU_API_TOKEN, SOURCE_BLOB_URL } = process.env
+
+            // Exit if GitHub Actions PAT is not found
+            if (!GITHUB_TOKEN) {
+              throw new Error('You must supply a GITHUB_TOKEN environment variable!')
+            }
+
+            // Exit if Heroku API token is not found
+            if (!HEROKU_API_TOKEN) {
+              throw new Error('You must supply a HEROKU_API_TOKEN environment variable!')
+            }
+
+            // Workaround to allow us to load ESM files with `require(...)`
+            const esm = require('esm')
+            require = esm({})
+
+            const { default: getOctokit } = require('./script/helpers/github')
+            const { default: deployToProduction } = require('./script/deployment/deploy-to-production')
+
+            // This helper uses the `GITHUB_TOKEN` implicitly!
+            // We're using our usual version of Octokit vs. the provided `github`
+            // instance to avoid versioning discrepancies.
+            const octokit = getOctokit()
+
+            try {
+              await deployToProduction({
+                octokit,
+                // These parameters will ONLY be set by Actions
+                sourceBlobUrl: SOURCE_BLOB_URL,
+                runId: context.runId
+              })
+            } catch (error) {
+              console.error(`Failed to deploy to production: ${error.message}`)
+              console.error(error)
+              throw error
+            }
+
+      - name: Mark the deployment as inactive if timed out
+        uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
+        if: ${{ steps.deploy.outcome == 'cancelled' }}
+        env:
+          DEPLOYMENT_ID: ${{ steps.deploy.outputs.deploymentId }}
+          LOG_URL: ${{ steps.deploy.outputs.logUrl }}
+        with:
+          script: |
+            const { DEPLOYMENT_ID, LOG_URL }  = process.env
+            const { owner, repo } = context.repo
+
+            if (!DEPLOYMENT_ID) {
+              throw new Error('A deployment wasn't created before a timeout occurred!')
+            }
+
+            await github.repos.createDeploymentStatus({
+              owner,
+              repo,
+              deployment_id: DEPLOYMENT_ID,
+              state: 'error',
+              description: 'The deployment step timed out. See workflow logs.',
+              log_url: LOG_URL,
+              // The 'ant-man' preview is required for `state` values of 'inactive', as well as
+              // the use of the `log_url`, `environment_url`, and `auto_inactive` parameters.
+              // The 'flash' preview is required for `state` values of 'in_progress' and 'queued'.
+              mediaType: {
+                previews: ['ant-man', 'flash'],
+              },
+            })
+            console.log('⏲️ Deployment status: error - The deployment timed out...')
+
+      - name: Purge Fastly edge cache
+        uses: actions/github-script@2b34a689ec86a68d8ab9478298f91d5401337b7d
+        env:
+          FASTLY_TOKEN: ${{ secrets.FASTLY_TOKEN }}
+          FASTLY_SERVICE_ID: ${{ secrets.FASTLY_SERVICE_ID }}
+          FASTLY_SURROGATE_KEY: 'all-the-things'
+          DELAY_FOR_PREBOOT: 'true'
+        with:
+          script: |
+            // Workaround to allow us to load ESM files with `require(...)`
+            const esm = require('esm')
+            require = esm({})
+
+            const { default: purgeEdgeCache } = require('./script/deployment/purge-edge-cache')
+
+            try {
+              await purgeEdgeCache({
+                includeDelayForPreboot: process.env.DELAY_FOR_PREBOOT !== 'false'
+              })
+            } catch (error) {
+              console.error(`Failed to purge the edge cache: ${error.message}`)
+              console.error(error)
+              throw error
+            }
+
+      - name: Send Slack notification if workflow fails
+        uses: someimportantcompany/github-actions-slack-message@0b470c14b39da4260ed9e3f9a4f1298a74ccdefd
+        if: ${{ failure() }}
+        with:
+          channel: ${{ secrets.DOCS_ALERTS_SLACK_CHANNEL_ID }}
+          bot-token: ${{ secrets.SLACK_DOCS_BOT_TOKEN }}
+          color: failure
+          text: Production deployment failed at commit ${{ github.sha }}. See https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}

script/deployment/deploy-to-production.js

@@ -0,0 +1,418 @@
+#!/usr/bin/env node
+import sleep from 'await-sleep'
+import got from 'got'
+import Heroku from 'heroku-client'
+import { setOutput } from '@actions/core'
+
+const SLEEP_INTERVAL = 5000
+const HEROKU_LOG_LINES_TO_SHOW = 25
+
+// Allow for a few 404 (Not Found) or 429 (Too Many Requests) responses from the
+// semi-unreliable Heroku API when we're polling for status updates
+const ALLOWED_MISSING_RESPONSE_COUNT = 5
+
+export default async function deployToProduction({
+  octokit,
+  // These parameters will only be set by Actions
+  sourceBlobUrl = null,
+  runId = null,
+}) {
+  // Start a timer so we can report how long the deployment takes
+  const startTime = Date.now()
+  const [owner, repo, branch] = ['github', 'docs-internal', 'main']
+
+  let sha
+  try {
+    const {
+      data: { sha: latestSha },
+    } = await octokit.repos.getCommit({
+      owner,
+      repo,
+      ref: branch,
+    })
+    sha = latestSha
+
+    if (!sha) {
+      throw new Error('Latest commit SHA could not be found')
+    }
+  } catch (error) {
+    console.error(`Error: ${error}`)
+    console.log(`🛑 There was an error getting latest commit.`)
+    process.exit(1)
+  }
+
+  // Put together application configuration variables
+  const isPrebuilt = !!sourceBlobUrl
+  const { DOCUBOT_REPO_PAT } = process.env
+  const appConfigVars = {
+    // Track the git branch
+    GIT_BRANCH: branch,
+    // If prebuilt: prevent the Heroku Node.js buildpack from installing devDependencies
+    NPM_CONFIG_PRODUCTION: isPrebuilt.toString(),
+    // If prebuilt: prevent the Heroku Node.js buildpack from using `npm ci` as it would
+    // delete all of the vendored "node_modules/" directory.
+    USE_NPM_INSTALL: isPrebuilt.toString(),
+    ...(!isPrebuilt && DOCUBOT_REPO_PAT && { DOCUBOT_REPO_PAT }),
+  }
+
+  const workflowRunLog = runId ? `https://github.com/${owner}/${repo}/actions/runs/${runId}` : null
+  let deploymentId = null
+  let logUrl = workflowRunLog
+
+  const appName = 'help-docs-prod-gha'
+  const homepageUrl = `https://${appName}.herokuapp.com/`
+
+  try {
+    const title = `branch '${branch}' at commit '${sha}' in the 'production' environment as '${appName}'`
+
+    console.log(`About to deploy ${title}...`)
+
+    // Kick off a pending GitHub Deployment right away, so the PR author
+    // will have instant feedback that their work is being deployed.
+    const { data: deployment } = await octokit.repos.createDeployment({
+      owner,
+      repo,
+      description: `Deploying ${title}`,
+      ref: sha,
+
+      // In the GitHub API, there can only be one active deployment per environment.
+      environment: appName,
+
+      // The status contexts to verify against commit status checks. If you omit
+      // this parameter, GitHub verifies all unique contexts before creating a
+      // deployment. To bypass checking entirely, pass an empty array. Defaults
+      // to all unique contexts.
+      required_contexts: [],
+
+      // Do not try to merge the base branch into the feature branch
+      auto_merge: false,
+    })
+    console.log('GitHub Deployment created', deployment)
+
+    // Store this ID for later updating
+    deploymentId = deployment.id
+
+    // Set some output variables for workflow steps that run after this script
+    if (process.env.GITHUB_ACTIONS) {
+      setOutput('deploymentId', deploymentId)
+      setOutput('logUrl', logUrl)
+    }
+
+    await octokit.repos.createDeploymentStatus({
+      owner,
+      repo,
+      deployment_id: deploymentId,
+      state: 'in_progress',
+      description: 'Deploying the app...',
+      // The 'ant-man' preview is required for `state` values of 'inactive', as well as
+      // the use of the `log_url`, `environment_url`, and `auto_inactive` parameters.
+      // The 'flash' preview is required for `state` values of 'in_progress' and 'queued'.
+      mediaType: {
+        previews: ['ant-man', 'flash'],
+      },
+    })
+    console.log('🚀 Deployment status: in_progress - Preparing to deploy the app...')
+
+    // Time to talk to Heroku...
+    const heroku = new Heroku({ token: process.env.HEROKU_API_TOKEN })
+    let build = null
+
+    if (!sourceBlobUrl) {
+      try {
+        sourceBlobUrl = await getTarballUrl({
+          octokit,
+          owner,
+          repo,
+          sha,
+        })
+      } catch (error) {
+        throw new Error(`Failed to generate source blob URL. Error: ${error}`)
+      }
+    }
+
+    console.log('Updating Heroku app configuration variables...')
+
+    // Reconfigure environment variables
+    // https://devcenter.heroku.com/articles/platform-api-reference#config-vars-update
+    try {
+      await heroku.patch(`/apps/${appName}/config-vars`, {
+        body: appConfigVars,
+      })
+    } catch (error) {
+      throw new Error(`Failed to update Heroku app configuration variables. Error: ${error}`)
+    }
+
+    console.log('Reconfigured')
+    console.log('Building Heroku app...')
+
+    try {
+      build = await heroku.post(`/apps/${appName}/builds`, {
+        body: {
+          source_blob: {
+            url: sourceBlobUrl,
+          },
+        },
+      })
+    } catch (error) {
+      throw new Error(`Failed to create Heroku build. Error: ${error}`)
+    }
+
+    console.log('Heroku build created', build)
+
+    const buildStartTime = Date.now() // Close enough...
+    const buildId = build.id
+    logUrl = build.output_stream_url
+
+    console.log('🚀 Deployment status: in_progress - Building a new Heroku slug...')
+
+    // Poll until the Build's status changes from "pending" to "succeeded" or "failed".
+    let buildAcceptableErrorCount = 0
+    while (!build || build.status === 'pending' || !build.release || !build.release.id) {
+      await sleep(SLEEP_INTERVAL)
+      try {
+        build = await heroku.get(`/apps/${appName}/builds/${buildId}`)
+      } catch (error) {
+        // Allow for a few bad responses from the Heroku API
+        if (error.statusCode === 404 || error.statusCode === 429) {
+          buildAcceptableErrorCount += 1
+          if (buildAcceptableErrorCount <= ALLOWED_MISSING_RESPONSE_COUNT) {
+            continue
+          }
+        }
+        throw new Error(`Failed to get build status. Error: ${error}`)
+      }
+
+      if (build && build.status === 'failed') {
+        throw new Error(
+          `Failed to build after ${Math.round(
+            (Date.now() - buildStartTime) / 1000
+          )} seconds. See Heroku logs for more information:\n${logUrl}`
+        )
+      }
+
+      console.log(
+        `Heroku build status: ${(build || {}).status} (after ${Math.round(
+          (Date.now() - buildStartTime) / 1000
+        )} seconds)`
+      )
+    }
+
+    console.log(
+      `Finished Heroku build after ${Math.round((Date.now() - buildStartTime) / 1000)} seconds.`,
+      build
+    )
+
+    const releaseStartTime = Date.now() // Close enough...
+    const releaseId = build.release.id
+    let release = null
+
+    // Poll until the associated Release's status changes from "pending" to "succeeded" or "failed".
+    let releaseAcceptableErrorCount = 0
+    while (!release || release.status === 'pending') {
+      await sleep(SLEEP_INTERVAL)
+      try {
+        const result = await heroku.get(`/apps/${appName}/releases/${releaseId}`)
+
+        // Update the deployment status but only on the first retrieval
+        if (!release) {
+          logUrl = result.output_stream_url
+
+          console.log('Heroku Release created', result)
+
+          console.log('🚀 Deployment status: in_progress - Releasing the built Heroku slug...')
+        }
+
+        release = result
+      } catch (error) {
+        // Allow for a few bad responses from the Heroku API
+        if (error.statusCode === 404 || error.statusCode === 429) {
+          releaseAcceptableErrorCount += 1
+          if (releaseAcceptableErrorCount <= ALLOWED_MISSING_RESPONSE_COUNT) {
+            continue
+          }
+        }
+        throw new Error(`Failed to get release status. Error: ${error}`)
+      }
+
+      if (release && release.status === 'failed') {
+        throw new Error(
+          `Failed to release after ${Math.round(
+            (Date.now() - releaseStartTime) / 1000
+          )} seconds. See Heroku logs for more information:\n${logUrl}`
+        )
+      }
+
+      console.log(
+        `Release status: ${(release || {}).status} (after ${Math.round(
+          (Date.now() - releaseStartTime) / 1000
+        )} seconds)`
+      )
+    }
+
+    console.log(
+      `Finished Heroku release after ${Math.round(
+        (Date.now() - releaseStartTime) / 1000
+      )} seconds.`,
+      release
+    )
+
+    // Monitor dyno state for this release to ensure it reaches "up" rather than crashing.
+    // This will help us catch issues with faulty startup code and/or the package manifest.
+    const dynoBootStartTime = Date.now()
+    console.log('Checking Heroku dynos...')
+    logUrl = workflowRunLog
+
+    console.log('🚀 Deployment status: in_progress - Monitoring the Heroku dyno start-up...')
+
+    // Keep checking while there are still dynos in non-terminal states
+    let newDynos = []
+    let dynoAcceptableErrorCount = 0
+    while (newDynos.length === 0 || newDynos.some((dyno) => dyno.state === 'starting')) {
+      await sleep(SLEEP_INTERVAL)
+      try {
+        const dynoList = await heroku.get(`/apps/${appName}/dynos`)
+        const dynosForThisRelease = dynoList.filter((dyno) => dyno.release.id === releaseId)
+
+        // To track them afterward
+        newDynos = dynosForThisRelease
+
+        console.log(
+          `Dyno states: ${JSON.stringify(newDynos.map((dyno) => dyno.state))} (after ${Math.round(
+            (Date.now() - dynoBootStartTime) / 1000
+          )} seconds)`
+        )
+      } catch (error) {
+        // Allow for a few bad responses from the Heroku API
+        if (error.statusCode === 404 || error.statusCode === 429) {
+          dynoAcceptableErrorCount += 1
+          if (dynoAcceptableErrorCount <= ALLOWED_MISSING_RESPONSE_COUNT) {
+            continue
+          }
+        }
+        throw new Error(`Failed to find dynos for this release. Error: ${error}`)
+      }
+    }
+
+    const crashedDynos = newDynos.filter((dyno) => ['crashed', 'restarting'].includes(dyno.state))
+    const runningDynos = newDynos.filter((dyno) => dyno.state === 'up')
+
+    // If any dynos crashed on start-up, fail the deployment
+    if (crashedDynos.length > 0) {
+      const errorMessage = `At least ${crashedDynos.length} Heroku dyno(s) crashed on start-up!`
+
+      console.error(errorMessage)
+
+      // Attempt to dump some of the Heroku log here for debugging
+      try {
+        const logSession = await heroku.post(`/apps/${appName}/log-sessions`, {
+          body: {
+            dyno: crashedDynos[0].name,
+            lines: HEROKU_LOG_LINES_TO_SHOW,
+            tail: false,
+          },
+        })
+
+        logUrl = logSession.logplex_url
+
+        const logText = await got(logUrl).text()
+        console.error(
+          `Here are the last ${HEROKU_LOG_LINES_TO_SHOW} lines of the Heroku log:\n\n${logText}`
+        )
+      } catch (error) {
+        // Don't fail because of this error
+        console.error(`Failed to retrieve the Heroku logs for the crashed dynos. Error: ${error}`)
+      }
+
+      throw new Error(errorMessage)
+    }
+
+    console.log(
+      `At least ${runningDynos.length} Heroku dyno(s) are ready after ${Math.round(
+        (Date.now() - dynoBootStartTime) / 1000
+      )} seconds.`
+    )
+
+    //
+    // TODO:
+    // Should we consider adding an explicit 2-minute pause here to allow for
+    // Heroku Preboot to actually swap in the new dynos?
+    //
+
+    // Report success!
+    const successMessage = `Deployment succeeded after ${Math.round(
+      (Date.now() - startTime) / 1000
+    )} seconds.`
+    console.log(successMessage)
+
+    await octokit.repos.createDeploymentStatus({
+      owner,
+      repo,
+      deployment_id: deploymentId,
+      state: 'success',
+      description: successMessage,
+      ...(logUrl && { log_url: logUrl }),
+      environment_url: homepageUrl,
+      // The 'ant-man' preview is required for `state` values of 'inactive', as well as
+      // the use of the `log_url`, `environment_url`, and `auto_inactive` parameters.
+      // The 'flash' preview is required for `state` values of 'in_progress' and 'queued'.
+      mediaType: {
+        previews: ['ant-man', 'flash'],
+      },
+    })
+
+    console.log(`🚀 Deployment status: success - ${successMessage}`)
+    console.log(`Visit the newly deployed app at: ${homepageUrl}`)
+  } catch (error) {
+    // Report failure!
+    const failureMessage = `Deployment failed after ${Math.round(
+      (Date.now() - startTime) / 1000
+    )} seconds. See logs for more information.`
+    console.error(failureMessage)
+
+    try {
+      if (deploymentId) {
+        await octokit.repos.createDeploymentStatus({
+          owner,
+          repo,
+          deployment_id: deploymentId,
+          state: 'error',
+          description: failureMessage,
+          ...(logUrl && { log_url: logUrl }),
+          environment_url: homepageUrl,
+          // The 'ant-man' preview is required for `state` values of 'inactive', as well as
+          // the use of the `log_url`, `environment_url`, and `auto_inactive` parameters.
+          // The 'flash' preview is required for `state` values of 'in_progress' and 'queued'.
+          mediaType: {
+            previews: ['ant-man', 'flash'],
+          },
+        })
+
+        console.log(
+          `🚀 Deployment status: error - ${failureMessage}` + (logUrl ? ` Logs: ${logUrl}` : '')
+        )
+      }
+    } catch (error) {
+      console.error(`Failed to finalize GitHub Deployment Status as a failure. Error: ${error}`)
+    }
+
+    // Re-throw the error to bubble up
+    throw error
+  }
+}
+
+async function getTarballUrl({ octokit, owner, repo, sha }) {
+  // Get a URL for the tarballed source code bundle
+  const {
+    headers: { location: tarballUrl },
+  } = await octokit.repos.downloadTarballArchive({
+    owner,
+    repo,
+    ref: sha,
+    // Override the underlying `node-fetch` module's `redirect` option
+    // configuration to prevent automatically following redirects.
+    request: {
+      redirect: 'manual',
+    },
+  })
+  return tarballUrl
+}

script/deployment/purge-edge-cache.js

@@ -0,0 +1,68 @@
+import sleep from 'await-sleep'
+import got from 'got'
+
+const ONE_SECOND = 1000
+const ONE_MINUTE = 60 * ONE_SECOND
+
+async function purgeFastlyBySurrogateKey({ apiToken, serviceId, surrogateKey }) {
+  const key = surrogateKey
+  const safeServiceId = encodeURIComponent(serviceId)
+
+  const headers = {
+    'fastly-key': apiToken,
+    accept: 'application/json',
+    'fastly-soft-purge': '1',
+  }
+  const requestPath = `https://api.fastly.com/service/${safeServiceId}/purge/${key}`
+  return got.post(requestPath, { headers, json: true })
+}
+
+// This delay (includeDelayForPreboot) can potentially be removed in the
+// future if the deployment workflow is updated to include a delay to offset
+// Heroku Preboot before this script runs.
+export default async function purgeEdgeCache({ includeDelayForPreboot = true } = {}) {
+  // If Heroku Preboot is enabled, then there is an additional delay of at
+  // least 2 minutes before the new dynos are swapped into active serving.
+  const delayForPrebootSwap = 2 * ONE_MINUTE + 30 * ONE_SECOND
+
+  // Give the app some extra time to wake up before the thundering herd of
+  // Fastly requests.
+  const delayBeforeFirstPurge = ONE_MINUTE
+
+  // Evidence has shown that it's necessary to purge twice to ensure all
+  // customers see fresh content.
+  const delayBeforeSecondPurge = 5 * ONE_SECOND
+
+  console.log('Fastly purgeEdgeCache initialized...')
+
+  const { FASTLY_TOKEN, FASTLY_SERVICE_ID, FASTLY_SURROGATE_KEY } = process.env
+  if (!FASTLY_TOKEN || !FASTLY_SERVICE_ID || !FASTLY_SURROGATE_KEY) {
+    console.log('Fastly env vars not detected; skipping purgeEdgeCache step')
+    return
+  }
+
+  const purgingParams = {
+    apiToken: FASTLY_TOKEN,
+    serviceId: FASTLY_SERVICE_ID,
+    surrogateKey: FASTLY_SURROGATE_KEY,
+  }
+
+  if (includeDelayForPreboot) {
+    console.log('Waiting for Heroku Preboot to swap dynos...')
+    await sleep(delayForPrebootSwap)
+  }
+
+  console.log('Waiting extra time to prevent a Thundering Herd problem...')
+  await sleep(delayBeforeFirstPurge)
+
+  console.log('Attempting first Fastly purge...')
+  const firstPurge = await purgeFastlyBySurrogateKey(purgingParams)
+  console.log('First Fastly purge result:', firstPurge.body || firstPurge)
+
+  console.log('Waiting to purge a second time...')
+  await sleep(delayBeforeSecondPurge)
+
+  console.log('Attempting second Fastly purge...')
+  const secondPurge = await purgeFastlyBySurrogateKey(purgingParams)
+  console.log('Second Fastly purge result:', secondPurge.body || secondPurge)
+}