[release notes] automatically retry on Github API 5xx errors

packages/kbn-release-notes/src/cli.ts

@@ -25,8 +25,7 @@ import { run, createFlagError, createFailError, REPO_ROOT } from '@kbn/dev-utils
 
 import { FORMATS, SomeFormat } from './formats';
 import {
-  iterRelevantPullRequests,
-  getPr,
+  PrApi,
   Version,
   ClassifiedPr,
   streamFromIterable,
@@ -48,6 +47,7 @@ export function runReleaseNotesCli() {
       if (!token || typeof token !== 'string') {
         throw createFlagError('--token must be defined');
       }
+      const prApi = new PrApi(log, token);
 
       const version = Version.fromFlag(flags.version);
       if (!version) {
@@ -80,7 +80,7 @@ export function runReleaseNotesCli() {
         }
 
         const summary = new IrrelevantPrSummary(log);
-        const pr = await getPr(token, number);
+        const pr = await prApi.getPr(number);
         log.success(
           inspect(
             {
@@ -101,7 +101,7 @@ export function runReleaseNotesCli() {
 
       const summary = new IrrelevantPrSummary(log);
       const prsToReport: ClassifiedPr[] = [];
-      const prIterable = iterRelevantPullRequests(token, version, log);
+      const prIterable = prApi.iterRelevantPullRequests(version);
       for await (const pr of prIterable) {
         if (!isPrRelevant(pr, version, includeVersions, summary)) {
           continue;

packages/kbn-release-notes/src/lib/classify_pr.ts

@@ -27,7 +27,7 @@ import {
   ASCIIDOC_SECTIONS,
   UNKNOWN_ASCIIDOC_SECTION,
 } from '../release_notes_config';
-import { PullRequest } from './pull_request';
+import { PullRequest } from './pr_api';
 
 export interface ClassifiedPr extends PullRequest {
   area: Area;

packages/kbn-release-notes/src/lib/index.ts

@@ -17,7 +17,7 @@
  * under the License.
  */
 
-export * from './pull_request';
+export * from './pr_api';
 export * from './version';
 export * from './is_pr_relevant';
 export * from './streams';

packages/kbn-release-notes/src/lib/irrelevant_pr_summary.ts

@@ -19,7 +19,7 @@
 
 import { ToolingLog } from '@kbn/dev-utils';
 
-import { PullRequest } from './pull_request';
+import { PullRequest } from './pr_api';
 import { Version } from './version';
 
 export class IrrelevantPrSummary {

packages/kbn-release-notes/src/lib/is_pr_relevant.ts

@@ -18,7 +18,7 @@
  */
 
 import { Version } from './version';
-import { PullRequest } from './pull_request';
+import { PullRequest } from './pr_api';
 import { IGNORE_LABELS } from '../release_notes_config';
 import { IrrelevantPrSummary } from './irrelevant_pr_summary';
 

packages/kbn-release-notes/src/lib/pr_api.ts

@@ -0,0 +1,231 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { inspect } from 'util';
+
+import Axios from 'axios';
+import gql from 'graphql-tag';
+import * as GraphqlPrinter from 'graphql/language/printer';
+import { DocumentNode } from 'graphql/language/ast';
+import makeTerminalLink from 'terminal-link';
+import { ToolingLog, isAxiosResponseError } from '@kbn/dev-utils';
+
+import { Version } from './version';
+import { getFixReferences } from './get_fix_references';
+import { getNoteFromDescription } from './get_note_from_description';
+
+const PrNodeFragment = gql`
+  fragment PrNode on PullRequest {
+    number
+    url
+    title
+    bodyText
+    bodyHTML
+    mergedAt
+    baseRefName
+    state
+    author {
+      login
+      ... on User {
+        name
+      }
+    }
+    labels(first: 100) {
+      nodes {
+        name
+      }
+    }
+  }
+`;
+
+export interface PullRequest {
+  number: number;
+  url: string;
+  title: string;
+  targetBranch: string;
+  mergedAt: string;
+  state: string;
+  labels: string[];
+  fixes: string[];
+  user: {
+    name: string;
+    login: string;
+  };
+  versions: Version[];
+  terminalLink: string;
+  note?: string;
+}
+
+export class PrApi {
+  constructor(private readonly log: ToolingLog, private readonly token: string) {}
+
+  async getPr(number: number) {
+    const resp = await this.gqlRequest(
+      gql`
+        query($number: Int!) {
+          repository(owner: "elastic", name: "kibana") {
+            pullRequest(number: $number) {
+              ...PrNode
+            }
+          }
+        }
+        ${PrNodeFragment}
+      `,
+      {
+        number,
+      }
+    );
+
+    const node = resp.data?.repository?.pullRequest;
+    if (!node) {
+      throw new Error(`unexpected github response, unable to fetch PR: ${inspect(resp)}`);
+    }
+
+    return this.parsePullRequestNode(node);
+  }
+
+  /**
+   * Iterate all of the PRs which have the `version` label
+   */
+  async *iterRelevantPullRequests(version: Version) {
+    let nextCursor: string | undefined;
+    let hasNextPage = true;
+
+    while (hasNextPage) {
+      const resp = await this.gqlRequest(
+        gql`
+          query($cursor: String, $labels: [String!]) {
+            repository(owner: "elastic", name: "kibana") {
+              pullRequests(first: 100, after: $cursor, labels: $labels, states: MERGED) {
+                pageInfo {
+                  hasNextPage
+                  endCursor
+                }
+                nodes {
+                  ...PrNode
+                }
+              }
+            }
+          }
+          ${PrNodeFragment}
+        `,
+        {
+          cursor: nextCursor,
+          labels: [version.label],
+        }
+      );
+
+      const pullRequests = resp.data?.repository?.pullRequests;
+      if (!pullRequests) {
+        throw new Error(`unexpected github response, unable to fetch PRs: ${inspect(resp)}`);
+      }
+
+      hasNextPage = pullRequests.pageInfo?.hasNextPage;
+      nextCursor = pullRequests.pageInfo?.endCursor;
+
+      if (hasNextPage === undefined || (hasNextPage && !nextCursor)) {
+        throw new Error(
+          `github response does not include valid pagination information: ${inspect(resp)}`
+        );
+      }
+
+      for (const node of pullRequests.nodes) {
+        yield this.parsePullRequestNode(node);
+      }
+    }
+  }
+
+  /**
+   * Convert the Github API response into the structure used by this tool
+   *
+   * @param node A GraphQL response from Github using the PrNode fragment
+   */
+  private parsePullRequestNode(node: any): PullRequest {
+    const terminalLink = makeTerminalLink(`#${node.number}`, node.url);
+
+    const labels: string[] = node.labels.nodes.map((l: { name: string }) => l.name);
+
+    return {
+      number: node.number,
+      url: node.url,
+      terminalLink,
+      title: node.title,
+      targetBranch: node.baseRefName,
+      state: node.state,
+      mergedAt: node.mergedAt,
+      labels,
+      fixes: getFixReferences(node.bodyText),
+      user: {
+        login: node.author?.login || 'deleted user',
+        name: node.author?.name,
+      },
+      versions: labels
+        .map((l) => Version.fromLabel(l))
+        .filter((v): v is Version => v instanceof Version),
+      note: getNoteFromDescription(node.bodyHTML),
+    };
+  }
+
+  /**
+   * Send a single request to the Github v4 GraphQL API
+   */
+  private async gqlRequest(query: DocumentNode, variables: Record<string, unknown> = {}) {
+    let attempt = 0;
+
+    while (true) {
+      attempt += 1;
+
+      try {
+        const resp = await Axios.request({
+          url: 'https://api.github.com/graphql',
+          method: 'POST',
+          headers: {
+            'user-agent': '@kbn/release-notes',
+            authorization: `bearer ${this.token}`,
+          },
+          data: {
+            query: GraphqlPrinter.print(query),
+            variables,
+          },
+        });
+
+        return resp.data;
+      } catch (error) {
+        if (!isAxiosResponseError(error) || error.response.status < 500) {
+          // rethrow error unless it is a 500+ response from github
+          throw error;
+        }
+
+        const { status, data } = error.response;
+        const resp = inspect(data);
+
+        if (attempt === 5) {
+          throw new Error(
+            `${status} response from Github, attempted request ${attempt} times: [${resp}]`
+          );
+        }
+
+        const delay = attempt * 2000;
+        this.log.debug(`Github responded with ${status}, retrying in ${delay} ms: [${resp}]`);
+        await new Promise((resolve) => setTimeout(resolve, delay));
+        continue;
+      }
+    }
+  }
+}