lint: Add commit/PR body linter for epic and issue refs

Before: Commits and PRs would inconsistently contain references to issues.
Sometimes the author would forget to add it. Some authors might not
think to add them. And there were no epic references provided.

Why: Adding issue and epic references to PRs and commits provides
traceability and context for the revenue teams, product, management and
engineers.

Now: A new GitHub Action workflow checks for references to issues the PR
closes or informs and epics the PR is part of. It looks for references
in the PR body and in commit messages and, if it doesn't find what it
expects, it fails the check.

Release note: None

Release justification: Adding linter for epic tracking for engineering,
docs, and internal teams.

.github/CODEOWNERS

@@ -255,6 +255,7 @@
 /pkg/cmd/gossipsim/          @cockroachdb/kv-prs
 /pkg/cmd/import-tools/       @cockroachdb/dev-inf
 /pkg/cmd/internal/issues/    @cockroachdb/test-eng
+/pkg/cmd/lint-epic-issue-refs/ @cockroachdb/dev-inf
 /pkg/cmd/mirror/             @cockroachdb/dev-inf
 /pkg/cmd/prereqs/            @cockroachdb/dev-inf
 /pkg/cmd/protoc-gen-gogoroach/ @cockroachdb/dev-inf

.github/workflows/pr-epic-issue-ref-lint.yml

@@ -0,0 +1,35 @@
+name: Epic + Issue Ref Linter for PR Body or Commit Messages
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize, edited]
+
+jobs:
+  linter:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Bazel cache
+        id: bazel-cache
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.cache/bazel
+          key: ${{ runner.os }}-bazel-cache
+
+      - name: Install bazelisk
+        run: |
+          curl -fsSL https://github.com/bazelbuild/bazelisk/releases/download/v1.10.1/bazelisk-linux-amd64 > /tmp/bazelisk
+          sha256sum -c - <<EOF
+          4cb534c52cdd47a6223d4596d530e7c9c785438ab3b0a49ff347e991c210b2cd /tmp/bazelisk
+          EOF
+          mkdir -p "${GITHUB_WORKSPACE}/bin/"
+          mv /tmp/bazelisk "${GITHUB_WORKSPACE}/bin/bazel"
+          chmod +x "${GITHUB_WORKSPACE}/bin/bazel"
+
+      - name: Run lint
+        run: build/github/pr-epic-issue-ref-lint.sh
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

build/github/pr-epic-issue-ref-lint.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+PR_NUMBER="$(echo "$GITHUB_REF" | awk -F '/' '{print $3}')"
+
+GITHUB_TOKEN="${GITHUB_TOKEN}" bin/bazel run //pkg/cmd/lint-epic-issue-refs:lint-epic-issue-refs "$PR_NUMBER"

pkg/BUILD.bazel

@@ -123,6 +123,7 @@ ALL_TESTS = [
     "//pkg/cmd/github-pull-request-make:github-pull-request-make_test",
     "//pkg/cmd/internal/issues:issues_test",
     "//pkg/cmd/label-merged-pr:label-merged-pr_test",
+    "//pkg/cmd/lint-epic-issue-refs:lint-epic-issue-refs_test",
     "//pkg/cmd/mirror:mirror_test",
     "//pkg/cmd/prereqs:prereqs_test",
     "//pkg/cmd/publish-artifacts:publish-artifacts_test",
@@ -927,6 +928,9 @@ GO_TARGETS = [
     "//pkg/cmd/label-merged-pr:label-merged-pr",
     "//pkg/cmd/label-merged-pr:label-merged-pr_lib",
     "//pkg/cmd/label-merged-pr:label-merged-pr_test",
+    "//pkg/cmd/lint-epic-issue-refs:lint-epic-issue-refs",
+    "//pkg/cmd/lint-epic-issue-refs:lint-epic-issue-refs_lib",
+    "//pkg/cmd/lint-epic-issue-refs:lint-epic-issue-refs_test",
     "//pkg/cmd/mirror:mirror",
     "//pkg/cmd/mirror:mirror_lib",
     "//pkg/cmd/mirror:mirror_test",
@@ -2321,6 +2325,7 @@ GET_X_DATA_TARGETS = [
     "//pkg/cmd/import-tools:get_x_data",
     "//pkg/cmd/internal/issues:get_x_data",
     "//pkg/cmd/label-merged-pr:get_x_data",
+    "//pkg/cmd/lint-epic-issue-refs:get_x_data",
     "//pkg/cmd/mirror:get_x_data",
     "//pkg/cmd/prereqs:get_x_data",
     "//pkg/cmd/protoc-gen-gogoroach:get_x_data",

pkg/cmd/lint-epic-issue-refs/BUILD.bazel

@@ -0,0 +1,33 @@
+load("//build/bazelutil/unused_checker:unused.bzl", "get_x_data")
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library", "go_test")
+
+go_library(
+    name = "lint-epic-issue-refs_lib",
+    srcs = [
+        "lint_epic_issue_refs.go",
+        "main.go",
+    ],
+    importpath = "github.com/cockroachdb/cockroach/pkg/cmd/lint-epic-issue-refs",
+    visibility = ["//visibility:private"],
+    deps = [
+        "@com_github_google_go_github//github",
+        "@com_github_spf13_cobra//:cobra",
+        "@org_golang_x_oauth2//:oauth2",
+    ],
+)
+
+go_binary(
+    name = "lint-epic-issue-refs",
+    embed = [":lint-epic-issue-refs_lib"],
+    visibility = ["//visibility:public"],
+)
+
+go_test(
+    name = "lint-epic-issue-refs_test",
+    srcs = ["lint_epic_issue_refs_test.go"],
+    args = ["-test.timeout=295s"],
+    embed = [":lint-epic-issue-refs_lib"],
+    deps = ["@com_github_stretchr_testify//assert"],
+)
+
+get_x_data(name = "get_x_data")