Support labels filtering on single PR usage

Dockerfile

@@ -2,21 +2,20 @@ ARG base_image=alpine
 ARG builder_image=golang
 
 FROM ${builder_image} as builder
-ADD . /go/src/github.com/aoldershaw/github-pr-resource
 WORKDIR /go/src/github.com/aoldershaw/github-pr-resource
 RUN curl -sL https://taskfile.dev/install.sh | sh
+ADD . /go/src/github.com/aoldershaw/github-pr-resource
 RUN ./bin/task build
 
 FROM ${base_image} as resource
 
 RUN apk add --update --no-cache \
     git \
     git-lfs \
-    openssh
+    openssh \
+    git-crypt
 
 COPY scripts/askpass.sh /usr/local/bin/askpass.sh
-ADD scripts/install_git_crypt.sh install_git_crypt.sh
-RUN ./install_git_crypt.sh && rm ./install_git_crypt.sh
 
 COPY --from=builder /go/src/github.com/aoldershaw/github-pr-resource/build /opt/resource
 

README.md

@@ -95,6 +95,7 @@ for a single PR.
 | `v4_endpoint`               | No       | `https://api.github.com/graphql` | Endpoint to use for the V4 Github API (Graphql).                                                                                                                                                                                                                                            |
 | `paths`                     | No       | `["terraform/*/*.tf"]`           | Only produce new versions for commits that include changes to files that match one or more glob patterns or prefixes. Note: this differs from `source.paths` when listing PRs in that it applies on a commit-by-commit basis, whereas the former applies for the full PR.                   |
 | `ignore_paths`              | No       | `[".ci/"]`                       | Inverse of the above. Pattern syntax is documented in [filepath.Match](https://golang.org/pkg/path/filepath/#Match), or a path prefix can be specified (e.g. `.ci/` will match everything in the `.ci` directory).                                                                          |
+| `labels`                    | No       | `["bug", "enhancement"]`         | The labels on the PR. The pipeline will only trigger on pull requests having at least one of the specified labels.                                                                                                                                                                          |
 | `disable_ci_skip`           | No       | `true`                           | Disable ability to skip builds with `[ci skip]` and `[skip ci]` in the commit message.                                                                                                                                                                                                      |
 | `git_crypt_key`             | No       | `AEdJVENSWVBUS0VZAAAAA...`       | Base64 encoded git-crypt key. Setting this will unlock / decrypt the repository with git-crypt. To get the key simply execute `git-crypt export-key -- - | base64` in an encrypted repository.                                                                                             |
 | `disable_git_lfs`           | No       | `true`                           | Disable Git LFS, skipping an attempt to convert pointers of files tracked into their corresponding objects when checked out into a working copy.                                                                                                                                           |

cmd/check/main.go

@@ -79,12 +79,18 @@ func checkPR(stdin []byte) {
 		log.Fatalf("failed to create temp dir: %v", err)
 	}
 
+	// github client for checking labels
+	github, err := resource.NewGithubClient(request.Source.CommonConfig, request.Source.GithubConfig)
+	if err != nil {
+		log.Fatalf("failed to create github manager: %v", err)
+	}
+
 	// We never need git-lfs when we check for new commits, so always disable it.
 	git, err := resource.NewGitClient(request.Source.CommonConfig, true, repoDir, os.Stderr)
 	if err != nil {
 		log.Fatalf("failed to create git manager: %v", err)
 	}
-	response, err := pr.Check(request, git)
+	response, err := pr.Check(request, git, github)
 	if err != nil {
 		log.Fatalf("check failed: %v", err)
 	}

github.go

@@ -204,6 +204,13 @@ func (m *GithubClient) GetPullRequest(prNumber int, commitRef string) (*PullRequ
 						}
 					}
 				} `graphql:"commits(last:$commitsLast)"`
+				Labels struct {
+					Edges []struct {
+						Node struct {
+							LabelObject
+						}
+					}
+				} `graphql:"labels(first:$labelsFirst)"`
 			} `graphql:"pullRequest(number:$prNumber)"`
 		} `graphql:"repository(owner:$repositoryOwner,name:$repositoryName)"`
 	}
@@ -213,19 +220,25 @@ func (m *GithubClient) GetPullRequest(prNumber int, commitRef string) (*PullRequ
 		"repositoryName":  githubv4.String(m.Repository),
 		"prNumber":        githubv4.Int(prNumber),
 		"commitsLast":     githubv4.Int(100),
+		"labelsFirst":     githubv4.Int(100),
 	}
 
 	// TODO: Pagination - in case someone pushes > 100 commits before the build has time to start :p
 	if err := m.V4.Query(context.TODO(), &query, vars); err != nil {
 		return nil, err
 	}
 
+	labels := make([]LabelObject, len(query.Repository.PullRequest.Labels.Edges))
+	for _, l := range query.Repository.PullRequest.Labels.Edges {
+		labels = append(labels, l.Node.LabelObject)
+	}
 	for _, c := range query.Repository.PullRequest.Commits.Edges {
 		if c.Node.Commit.OID == commitRef {
 			// Return as soon as we find the correct ref.
 			return &PullRequest{
 				PullRequestObject: query.Repository.PullRequest.PullRequestObject,
 				Tip:               c.Node.Commit,
+				Labels:            labels,
 			}, nil
 		}
 	}

pr/check.go

@@ -1,10 +1,13 @@
 package pr
 
 import (
+	"fmt"
+
 	resource "github.com/aoldershaw/github-pr-resource"
 )
 
-func Check(request CheckRequest, git resource.Git) (CheckResponse, error) {
+func Check(request CheckRequest, git resource.Git, manager resource.Github) (CheckResponse, error) {
+	// First check commits
 	if err := git.Init(nil); err != nil {
 		return CheckResponse{}, err
 	}
@@ -28,6 +31,27 @@ func Check(request CheckRequest, git resource.Git) (CheckResponse, error) {
 		response[i] = Version{Ref: commit}
 	}
 
+	if len(commits) != 0 && len(request.Source.Labels) != 0 {
+		// Filter by PR labels
+		pull, err := manager.GetPullRequest(request.Source.Number, commits[0])
+		if err != nil {
+			return nil, fmt.Errorf("failed to get pull request: %s", err)
+		}
+		labelFound := false
+	LabelLoop:
+		for _, wantedLabel := range request.Source.Labels {
+			for _, targetLabel := range pull.Labels {
+				if targetLabel.Name == wantedLabel {
+					labelFound = true
+					break LabelLoop
+				}
+			}
+		}
+		if !labelFound {
+			return make(CheckResponse, 0), nil
+		}
+	}
+
 	return response, nil
 }
 

pr/models.go

@@ -16,6 +16,7 @@ type Source struct {
 	Paths         []string `json:"paths"`
 	IgnorePaths   []string `json:"ignore_paths"`
 	DisableCISkip bool     `json:"disable_ci_skip"`
+	Labels        []string `json:"labels"`
 }
 
 // Validate the source configuration.