Github bug reviver

For everyone's joy, this is a tool that reopens issues that
have been closed, but are still referenced by TODOs in the
code. The idea is to run it in Kokoro nightly. Kokoro changes
are coming up next.

PiperOrigin-RevId: 288789560

2 files changed, 181 insertions, 0 deletions

diff --git a/tools/issue_reviver/github/BUILD b/tools/issue_reviver/github/BUILD
new file mode 100644
index 000000000..6da22ba1c
--- /dev/null
+++ b/tools/issue_reviver/github/BUILD
@@ -0,0 +1,17 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+    name = "github",
+    srcs = ["github.go"],
+    importpath = "gvisor.dev/gvisor/tools/issue_reviver/github",
+    visibility = [
+        "//tools/issue_reviver:__subpackages__",
+    ],
+    deps = [
+        "//tools/issue_reviver/reviver",
+        "@com_github_google_go-github//github:go_default_library",
+        "@org_golang_x_oauth2//:go_default_library",
+    ],
+)
diff --git a/tools/issue_reviver/github/github.go b/tools/issue_reviver/github/github.go
new file mode 100644
index 000000000..e07949c8f
--- /dev/null
+++ b/tools/issue_reviver/github/github.go
@@ -0,0 +1,164 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed 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.
+
+// Package github implements reviver.Bugger interface on top of Github issues.
+package github
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/google/go-github/github"
+	"golang.org/x/oauth2"
+	"gvisor.dev/gvisor/tools/issue_reviver/reviver"
+)
+
+// Bugger implements reviver.Bugger interface for github issues.
+type Bugger struct {
+	owner  string
+	repo   string
+	dryRun bool
+
+	client *github.Client
+	issues map[int]*github.Issue
+}
+
+// NewBugger creates a new Bugger.
+func NewBugger(token, owner, repo string, dryRun bool) (*Bugger, error) {
+	b := &Bugger{
+		owner:  owner,
+		repo:   repo,
+		dryRun: dryRun,
+		issues: map[int]*github.Issue{},
+	}
+	if err := b.load(token); err != nil {
+		return nil, err
+	}
+	return b, nil
+}
+
+func (b *Bugger) load(token string) error {
+	ctx := context.Background()
+	if len(token) == 0 {
+		fmt.Print("No OAUTH token provided, using unauthenticated account.\n")
+		b.client = github.NewClient(nil)
+	} else {
+		ts := oauth2.StaticTokenSource(
+			&oauth2.Token{AccessToken: token},
+		)
+		tc := oauth2.NewClient(ctx, ts)
+		b.client = github.NewClient(tc)
+	}
+
+	err := processAllPages(func(listOpts github.ListOptions) (*github.Response, error) {
+		opts := &github.IssueListByRepoOptions{State: "open", ListOptions: listOpts}
+		tmps, resp, err := b.client.Issues.ListByRepo(ctx, b.owner, b.repo, opts)
+		if err != nil {
+			return resp, err
+		}
+		for _, issue := range tmps {
+			b.issues[issue.GetNumber()] = issue
+		}
+		return resp, nil
+	})
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("Loaded %d issues from github.com/%s/%s\n", len(b.issues), b.owner, b.repo)
+	return nil
+}
+
+// Activate implements reviver.Bugger.
+func (b *Bugger) Activate(todo *reviver.Todo) (bool, error) {
+	const prefix = "gvisor.dev/issue/"
+
+	// First check if I can handle the TODO.
+	idStr := strings.TrimPrefix(todo.Issue, prefix)
+	if len(todo.Issue) == len(idStr) {
+		return false, nil
+	}
+
+	id, err := strconv.Atoi(idStr)
+	if err != nil {
+		return true, err
+	}
+
+	// Check against active issues cache.
+	if _, ok := b.issues[id]; ok {
+		fmt.Printf("%q is active: OK\n", todo.Issue)
+		return true, nil
+	}
+
+	fmt.Printf("%q is not active: reopening issue %d\n", todo.Issue, id)
+
+	// Format comment with TODO locations and search link.
+	comment := strings.Builder{}
+	fmt.Fprintln(&comment, "There are TODOs still referencing this issue:")
+	for _, l := range todo.Locations {
+		fmt.Fprintf(&comment,
+			"1. [%s:%d](https://github.com/%s/%s/blob/HEAD/%s#%d): %s\n",
+			l.File, l.Line, b.owner, b.repo, l.File, l.Line, l.Comment)
+	}
+	fmt.Fprintf(&comment,
+		"\n\nSearch [TODO](https://github.com/%s/%s/search?q=%%22%s%d%%22)", b.owner, b.repo, prefix, id)
+
+	if b.dryRun {
+		fmt.Printf("[dry-run: skipping change to issue %d]\n%s\n=======================\n", id, comment.String())
+		return true, nil
+	}
+
+	ctx := context.Background()
+	req := &github.IssueRequest{State: github.String("open")}
+	_, _, err = b.client.Issues.Edit(ctx, b.owner, b.repo, id, req)
+	if err != nil {
+		return true, fmt.Errorf("failed to reactivate issue %d: %v", id, err)
+	}
+
+	cmt := &github.IssueComment{
+		Body:      github.String(comment.String()),
+		Reactions: &github.Reactions{Confused: github.Int(1)},
+	}
+	if _, _, err := b.client.Issues.CreateComment(ctx, b.owner, b.repo, id, cmt); err != nil {
+		return true, fmt.Errorf("failed to add comment to issue %d: %v", id, err)
+	}
+
+	return true, nil
+}
+
+func processAllPages(fn func(github.ListOptions) (*github.Response, error)) error {
+	opts := github.ListOptions{PerPage: 1000}
+	for {
+		resp, err := fn(opts)
+		if err != nil {
+			if rateErr, ok := err.(*github.RateLimitError); ok {
+				duration := rateErr.Rate.Reset.Sub(time.Now())
+				if duration > 5*time.Minute {
+					return fmt.Errorf("Rate limited for too long: %v", duration)
+				}
+				fmt.Printf("Rate limited, sleeping for: %v\n", duration)
+				time.Sleep(duration)
+				continue
+			}
+			return err
+		}
+		if resp.NextPage == 0 {
+			return nil
+		}
+		opts.Page = resp.NextPage
+	}
+}