ci(docs-infra): rename 'upload-server' to 'preview-server'

The server no longer has files uploaded to it. Instead it is more
accurate to refer to it as dealing with "previews" of PRs.

aio/aio-builds-setup/dockerbuild/scripts-js/lib/preview-server/preview-server-factory.ts

@@ -0,0 +1,183 @@
+// Imports
+import * as bodyParser from 'body-parser';
+import * as express from 'express';
+import * as http from 'http';
+import {CircleCiApi} from '../common/circle-ci-api';
+import {GithubApi} from '../common/github-api';
+import {GithubPullRequests} from '../common/github-pull-requests';
+import {GithubTeams} from '../common/github-teams';
+import {assert, assertNotMissingOrEmpty, createLogger} from '../common/utils';
+import {BuildCreator} from './build-creator';
+import {ChangedPrVisibilityEvent, CreatedBuildEvent} from './build-events';
+import {BuildRetriever} from './build-retriever';
+import {BuildVerifier} from './build-verifier';
+import {respondWithError, throwRequestError} from './utils';
+
+const AIO_PREVIEW_JOB = 'aio_preview';
+
+// Interfaces - Types
+export interface PreviewServerConfig {
+  downloadsDir: string;
+  downloadSizeLimit: number;
+  buildArtifactPath: string;
+  buildsDir: string;
+  domainName: string;
+  githubOrg: string;
+  githubRepo: string;
+  githubTeamSlugs: string[];
+  circleCiToken: string;
+  githubToken: string;
+  significantFilesPattern: string;
+  trustedPrLabel: string;
+}
+
+const logger = createLogger('PreviewServer');
+
+// Classes
+export class PreviewServerFactory {
+  // Methods - Public
+  public static create(cfg: PreviewServerConfig): http.Server {
+    assertNotMissingOrEmpty('domainName', cfg.domainName);
+
+    const circleCiApi = new CircleCiApi(cfg.githubOrg, cfg.githubRepo, cfg.circleCiToken);
+    const githubApi = new GithubApi(cfg.githubToken);
+    const prs = new GithubPullRequests(githubApi, cfg.githubOrg, cfg.githubRepo);
+    const teams = new GithubTeams(githubApi, cfg.githubOrg);
+
+    const buildRetriever = new BuildRetriever(circleCiApi, cfg.downloadSizeLimit, cfg.downloadsDir);
+    const buildVerifier = new BuildVerifier(prs, teams, cfg.githubTeamSlugs, cfg.trustedPrLabel);
+    const buildCreator = PreviewServerFactory.createBuildCreator(prs, cfg.buildsDir, cfg.domainName);
+
+    const middleware = PreviewServerFactory.createMiddleware(buildRetriever, buildVerifier, buildCreator, cfg);
+    const httpServer = http.createServer(middleware as any);
+
+    httpServer.on('listening', () => {
+      const info = httpServer.address();
+      logger.info(`Up and running (and listening on ${info.address}:${info.port})...`);
+    });
+
+    return httpServer;
+  }
+
+  public static createMiddleware(buildRetriever: BuildRetriever, buildVerifier: BuildVerifier,
+                                 buildCreator: BuildCreator, cfg: PreviewServerConfig): express.Express {
+    const middleware = express();
+    const jsonParser = bodyParser.json();
+
+    // RESPOND TO IS-ALIVE PING
+    middleware.get(/^\/health-check\/?$/, (_req, res) => res.sendStatus(200));
+
+    // CIRCLE_CI BUILD COMPLETE WEBHOOK
+    middleware.post(/^\/circle-build\/?$/, jsonParser, async (req, res) => {
+      try {
+        if (!(
+          req.is('json') &&
+          req.body &&
+          req.body.payload &&
+          req.body.payload.build_num > 0 &&
+          req.body.payload.build_parameters &&
+          req.body.payload.build_parameters.CIRCLE_JOB
+        )) {
+          throwRequestError(400, `Incorrect body content. Expected JSON`, req);
+        }
+
+        const job = req.body.payload.build_parameters.CIRCLE_JOB;
+        const buildNum = req.body.payload.build_num;
+
+        logger.log(`Build:${buildNum}, Job:${job} - processing web-hook trigger`);
+
+        if (job !== AIO_PREVIEW_JOB) {
+          res.sendStatus(204);
+          logger.log(`Build:${buildNum}, Job:${job} -`,
+                     `Skipping preview processing because this is not the "${AIO_PREVIEW_JOB}" job.`);
+          return;
+        }
+
+        const { pr, sha, org, repo, success } = await buildRetriever.getGithubInfo(buildNum);
+
+        if (!success) {
+          res.sendStatus(204);
+          logger.log(`PR:${pr}, Build:${buildNum} - Skipping preview processing because this build did not succeed.`);
+          return;
+        }
+
+        assert(cfg.githubOrg === org,
+          `Invalid webhook: expected "githubOrg" property to equal "${cfg.githubOrg}" but got "${org}".`);
+        assert(cfg.githubRepo === repo,
+          `Invalid webhook: expected "githubRepo" property to equal "${cfg.githubRepo}" but got "${repo}".`);
+
+        // Do not deploy unless this PR has touched relevant files: `aio/` or `packages/` (except for spec files)
+        if (!await buildVerifier.getSignificantFilesChanged(pr, new RegExp(cfg.significantFilesPattern))) {
+          res.sendStatus(204);
+          logger.log(`PR:${pr}, Build:${buildNum} - ` +
+                     `Skipping preview processing because this PR did not touch any significant files.`);
+          return;
+        }
+
+        const artifactPath = await buildRetriever.downloadBuildArtifact(buildNum, pr, sha, cfg.buildArtifactPath);
+        const isPublic = await buildVerifier.getPrIsTrusted(pr);
+        await buildCreator.create(pr, sha, artifactPath, isPublic);
+        res.sendStatus(isPublic ? 201 : 202);
+      } catch (err) {
+        logger.error('CircleCI webhook error', err);
+        respondWithError(res, err);
+      }
+    });
+
+    // GITHUB PR UPDATED WEBHOOK
+    middleware.post(/^\/pr-updated\/?$/, jsonParser, async (req, res) => {
+      const { action, number: prNo }: { action?: string, number?: number } = req.body;
+      const visMayHaveChanged = !action || (action === 'labeled') || (action === 'unlabeled');
+
+      try {
+        if (!visMayHaveChanged) {
+          res.sendStatus(200);
+        } else if (!prNo) {
+          throwRequestError(400, `Missing or empty 'number' field`, req);
+        } else {
+          const isPublic = await buildVerifier.getPrIsTrusted(prNo);
+          await buildCreator.updatePrVisibility(prNo, isPublic);
+          res.sendStatus(200);
+        }
+      } catch (err) {
+        logger.error('PR update hook error', err);
+        respondWithError(res, err);
+      }
+    });
+
+    // ALL OTHER REQUESTS
+    middleware.all('*', req => throwRequestError(404, 'Unknown resource', req));
+    middleware.use((err: any, _req: any, res: express.Response, _next: any) => {
+      const statusText = http.STATUS_CODES[err.status] || '???';
+      logger.error(`Preview server error: ${err.status} - ${statusText}:`, err.message);
+      respondWithError(res, err);
+    });
+
+    return middleware;
+  }
+
+  public static createBuildCreator(prs: GithubPullRequests, buildsDir: string, domainName: string): BuildCreator {
+    const buildCreator = new BuildCreator(buildsDir);
+    const postPreviewsComment = (pr: number, shas: string[]) => {
+      const body = shas.
+        map(sha => `You can preview ${sha} at https://pr${pr}-${sha}.${domainName}/.`).
+        join('\n');
+
+      return prs.addComment(pr, body);
+    };
+
+    buildCreator.on(CreatedBuildEvent.type, ({pr, sha, isPublic}: CreatedBuildEvent) => {
+      if (isPublic) {
+        postPreviewsComment(pr, [sha]);
+      }
+    });
+
+    buildCreator.on(ChangedPrVisibilityEvent.type, ({pr, shas, isPublic}: ChangedPrVisibilityEvent) => {
+      if (isPublic && shas.length) {
+        postPreviewsComment(pr, shas);
+      }
+    });
+
+    return buildCreator;
+  }
+}