chore(internal/postprocessor): be selective about what PRs to update (#7280)

This limits the scope of which PRs are updated by our postprocessor.
In the future we may actually want our post processor to run some
tidy commands and vet peoples code for them. But we should discuss
this with the rest of the team first.

Author: codyoss

.github/.OwlBot.lock.yaml

@@ -13,4 +13,4 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-go:latest
-  digest: sha256:614ecada3e5d1610bf15439e389c455f26fb070d0a14aee87cf5b6a15d753153
+  digest: sha256:989e97271b91bb0bd869bd5d714d1ea076136090657aab7ba30635bfa1b38395

internal/README.md

@@ -24,3 +24,20 @@ To kick off a build locally run from the repo root:
 ```bash
 gcloud builds submit --project=cloud-devrel-kokoro-resources --config=internal/cloudbuild.yaml
 ```
+
+### Updating OwlBot SHA
+
+You may want to manually update the which version of the post processor will be
+used -- to do this you need to update the SHA in the OwlBot lock file. Start by
+running the following commands:
+
+```bash
+docker pull gcr.io/cloud-devrel-public-resources/owlbot-go:latest
+docker inspect --format='{{index .RepoDigests 0}}' gcr.io/cloud-devrel-public-resources/owlbot-go:latest
+```
+
+This will give you a SHA. You can use this value to update the value in
+`.github/.OwlBot.lock.yaml`.
+
+*Note*: OwlBot will eventually open a pull request to update this value if it
+discovers a new version of the container.

internal/postprocessor/README.md

@@ -1,33 +1,56 @@
 # postprocessor
 
 ## Running OwlBot locally
-Follow instructions in [OwlBot Usage Guide - "How will I test my .github/.OwlBot.yaml file"](https://g3doc.corp.google.com/company/teams/cloud-client-libraries/team/automation/docs/owlbot-usage-guide.md?cl=head#how-will-i-test-my-githubowlbotyaml-file) using the instructions for **split repositories**.
-  - Note, if you replace step 2 with a clone of your own fork of the `googleapis/googleapis-gen.git` repo, you can see how changes in your forked `googleapis-gen` repo are eventually propagated through to the library without making changes to the protos. Lack of permissions may also force you to clone a fork instead of the repo.
 
-After following these steps the generated code will have replaced corresponding files in the `google-cloud-go` repo.
+Follow instructions in [OwlBot Usage Guide - "How will I test my .github/.OwlBot.yaml file"](https://g3doc.corp.google.com/company/teams/cloud-client-libraries/team/automation/docs/owlbot-usage-guide.md?cl=head#how-will-i-test-my-githubowlbotyaml-file) using the instructions for
+**split repositories**.
+**Note**, if you replace step 2 with a clone of your own fork of the
+`googleapis/googleapis-gen.git` repo, you can see how changes in your forked
+`googleapis-gen` repo are eventually propagated through to the library without
+making changes to the protos. Lack of permissions may also force you to clone a
+fork instead of the repo.
+
+After following these steps the generated code will have replaced corresponding
+files in the `google-cloud-go` repo.
 
 ## Docker container
-The Docker container needs to be built with the context of the entire `google-cloud-go/internal` directory. When building the container, do so from the `google-cloud-go/internal` directory
+
+The Docker container needs to be built with the context of the entire
+`google-cloud-go/internal` directory. When building the container, do so from
+the `google-cloud-go/internal` directory
 
 ## Running the post-processor locally
-The Docker container name needed will be found in the `.github/OwlBot.yaml` and `github/OwlBot.lock.yaml` files.
-    ```
-- To run post-processor run:
-    ```sh
-    docker pull <container-name>
-    docker run --user $(id -u):$(id -g) --rm -v $(pwd):/repo -w /repo <container-name>
-    ```
+
+The Docker container name needed will be found in the `.github/OwlBot.yaml` and
+`github/OwlBot.lock.yaml` files.
+To run post-processor run:
+
+```bash
+docker pull <container-name>
+docker run --user $(id -u):$(id -g) --rm -v $(pwd):/repo -w /repo <container-name>
+```
 
 ## Testing the post-processor locally
-You can run the post-processor locally on selected directories or on all of the clients in the root directory.
+
+You can run the post-processor locally on selected directories or on all of the
+clients in the root directory.
 
 ### Run post-processor on all clients
-From the `google-cloud-go/internal/postprocessor` directory run: 
-```sh
+
+From the `google-cloud-go/internal/postprocessor` directory run:
+
+```bash
 go run main.go -stage-dir="../../owl-bot-staging/src/" -client-root="../.." -googleapis-dir="/path/to/local/googleapis"
 ```
+
 ### Run post-processor on select clients
-From the `google-cloud-go/internal/postprocessor` directory run the same command, but with an added `dirs` flag containing a comma-separated list of the names of the clients on which to run the post-processor. The example below shows the command for running the post-processor on the `accessapproval` and `asset` libraries:
-```sh
+
+From the `google-cloud-go/internal/postprocessor` directory run the same
+command, but with an added `dirs` flag containing a comma-separated list of the
+names of the clients on which to run the post-processor. The example below shows
+the command for running the post-processor on the `accessapproval` and `asset`
+libraries:
+
+```bash
 go run main.go -stage-dir="../../owl-bot-staging/src/" -client-root="../.." -googleapis-dir="/path/to/local/googleapis" -dirs="accessapproval,asset"
 ```

internal/postprocessor/main.go

@@ -37,32 +37,40 @@ import (
 	"gopkg.in/yaml.v2"
 )
 
-var apiNameOwlBotScope = "[REPLACEME]"
-
-// hashFromLinePattern grabs the hash from the end of a github commit URL
-var hashFromLinePattern = regexp.MustCompile(`.*/(?P<hash>[a-zA-Z0-9]*).*`)
-
-// firstPartTitlePattern grabs the existing commit title before the ': [REPLACEME]'
-var firstPartTitlePattern = regexp.MustCompile(`(?P<titleFirstPart>)(\: *\` + apiNameOwlBotScope + `)(.*)`)
+const (
+	owlBotBranchPrefix = "owl-bot-copy"
+	apiNameOwlBotScope = "[REPLACEME]"
+)
 
-// secondPartTitlePattern grabs the commit title after the ': [REPLACME]'
-var secondPartTitlePattern = regexp.MustCompile(`.*\: *\` + apiNameOwlBotScope + ` *(?P<titleSecondPart>.*)`)
+var (
+	// hashFromLinePattern grabs the hash from the end of a github commit URL
+	hashFromLinePattern = regexp.MustCompile(`.*/(?P<hash>[a-zA-Z0-9]*).*`)
+	// firstPartTitlePattern grabs the existing commit title before the ': [REPLACEME]'
+	firstPartTitlePattern = regexp.MustCompile(`(?P<titleFirstPart>)(\: *\` + apiNameOwlBotScope + `)(.*)`)
+	// secondPartTitlePattern grabs the commit title after the ': [REPLACME]'
+	secondPartTitlePattern = regexp.MustCompile(`.*\: *\` + apiNameOwlBotScope + ` *(?P<titleSecondPart>.*)`)
+)
 
 func main() {
 	clientRoot := flag.String("client-root", "/workspace/google-cloud-go", "Path to clients.")
 	googleapisDir := flag.String("googleapis-dir", "", "Path to googleapis/googleapis repo.")
 	directories := flag.String("dirs", "", "Comma-separated list of module names to run (not paths).")
-	branchPrefix := flag.String("branch", "owl-bot-copy", "The prefix of the branch that OwlBot opens when working on a PR.")
+	branchOverride := flag.String("branch", "", "The branch that should be processed by this code")
 	githubUsername := flag.String("gh-user", "googleapis", "GitHub username where repo lives.")
 	prFilepath := flag.String("pr-file", "/workspace/new_pull_request_text.txt", "Path at which to write text file if changing PR title or body.")
 
 	flag.Parse()
 
+	runAll, err := runAll(*clientRoot, *branchOverride)
+	if err != nil {
+		log.Fatal(err)
+	}
+
 	ctx := context.Background()
 
 	log.Println("client-root set to", *clientRoot)
 	log.Println("googleapis-dir set to", *googleapisDir)
-	log.Println("branch set to", *branchPrefix)
+	log.Println("branch set to", *branchOverride)
 	log.Println("prFilepath is", *prFilepath)
 
 	var modules []string
@@ -96,9 +104,10 @@ func main() {
 		googleapisDir:  *googleapisDir,
 		googleCloudDir: *clientRoot,
 		modules:        modules,
-		branchPrefix:   *branchPrefix,
+		branchOverride: *branchOverride,
 		githubUsername: *githubUsername,
 		prFilepath:     *prFilepath,
+		runAll:         runAll,
 	}
 
 	if err := c.run(ctx); err != nil {
@@ -112,12 +121,35 @@ type config struct {
 	googleapisDir  string
 	googleCloudDir string
 	modules        []string
-	branchPrefix   string
+	branchOverride string
 	githubUsername string
 	prFilepath     string
+	runAll         bool
+}
+
+// runAll uses git to tell if the PR being updated should run all post
+// processing logic.
+func runAll(dir, branchOverride string) (bool, error) {
+	if branchOverride != "" {
+		// This means we are running the post processor locally and want it to
+		// fully function -- so we lie.
+		return true, nil
+	}
+	c := execv.Command("git", "rev-parse", "--abbrev-ref", "HEAD")
+	c.Dir = dir
+	b, err := c.Output()
+	if err != nil {
+		return false, err
+	}
+	branchName := strings.TrimSpace(string(b))
+	return strings.HasPrefix(branchName, owlBotBranchPrefix), nil
 }
 
 func (c *config) run(ctx context.Context) error {
+	if !c.runAll {
+		log.Println("exiting post processing early")
+		return nil
+	}
 	if err := gocmd.ModTidyAll(c.googleCloudDir); err != nil {
 		return err
 	}
@@ -130,6 +162,8 @@ func (c *config) run(ctx context.Context) error {
 	if _, err := c.Manifest(generator.MicrogenGapicConfigs); err != nil {
 		return err
 	}
+	// TODO(codyoss): In the future we may want to make it possible to be able
+	// to run this locally with a user defined remote branch.
 	if err := c.AmendPRDescription(ctx); err != nil {
 		return err
 	}
@@ -300,8 +334,12 @@ func (c *config) getPR(ctx context.Context) (*github.PullRequest, error) {
 		return nil, err
 	}
 	var owlbotPR *github.PullRequest
+	branch := c.branchOverride
+	if c.branchOverride == "" {
+		branch = owlBotBranchPrefix
+	}
 	for _, pr := range prs {
-		if strings.Contains(*pr.Head.Label, c.branchPrefix) {
+		if strings.Contains(*pr.Head.Label, branch) {
 			owlbotPR = pr
 		}
 	}