internal/civisibility: add extra tags to github action pull_requests …

…runs (#2922)

internal/civisibility/constants/git.go

@@ -49,4 +49,13 @@ const (
 	// GitTag indicates the current git tag.
 	// This constant is used to tag traces with the tag name associated with the current commit.
 	GitTag = "git.tag"
+
+	// GitHeadCommit indicates the GIT head commit hash.
+	GitHeadCommit = "git.commit.head_sha"
+
+	// GitPrBaseCommit indicates the GIT PR base commit hash.
+	GitPrBaseCommit = "git.pull_request.base_branch_sha"
+
+	// GitPrBaseBranch indicates the GIT PR base branch name.
+	GitPrBaseBranch = "git.pull_request.base_branch"
 )

internal/civisibility/utils/ci_providers.go

@@ -408,6 +408,38 @@ func extractGithubActions() map[string]string {
 		tags[constants.CIEnvVars] = string(jsonString)
 	}
 
+	// Extract PR information from the github event json file
+	eventFilePath := os.Getenv("GITHUB_EVENT_PATH")
+	if stats, ok := os.Stat(eventFilePath); ok == nil && !stats.IsDir() {
+		if eventFile, err := os.Open(eventFilePath); err == nil {
+			defer eventFile.Close()
+
+			var eventJson struct {
+				PullRequest struct {
+					Base struct {
+						Sha string `json:"sha"`
+						Ref string `json:"ref"`
+					} `json:"base"`
+					Head struct {
+						Sha string `json:"sha"`
+					} `json:"head"`
+				} `json:"pull_request"`
+			}
+
+			eventDecoder := json.NewDecoder(eventFile)
+			if eventDecoder.Decode(&eventJson) == nil {
+				tags[constants.GitHeadCommit] = eventJson.PullRequest.Head.Sha
+				tags[constants.GitPrBaseCommit] = eventJson.PullRequest.Base.Sha
+				tags[constants.GitPrBaseBranch] = eventJson.PullRequest.Base.Ref
+			}
+		}
+	}
+
+	// Fallback if GitPrBaseBranch is not set
+	if tmpVal, ok := tags[constants.GitPrBaseBranch]; !ok || tmpVal == "" {
+		tags[constants.GitPrBaseBranch] = os.Getenv("GITHUB_BASE_REF")
+	}
+
 	return tags
 }
 

internal/civisibility/utils/ci_providers_test.go

@@ -13,6 +13,8 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"gopkg.in/DataDog/dd-trace-go.v1/internal/civisibility/constants"
 )
 
 func setEnvs(t *testing.T, env map[string]string) {
@@ -114,3 +116,43 @@ func TestTags(t *testing.T) {
 		})
 	}
 }
+
+func TestGitHubEventFile(t *testing.T) {
+	originalEventPath := os.Getenv("GITHUB_EVENT_PATH")
+	originalBaseRef := os.Getenv("GITHUB_BASE_REF")
+	defer func() {
+		os.Setenv("GITHUB_EVENT_PATH", originalEventPath)
+		os.Setenv("GITHUB_BASE_REF", originalBaseRef)
+	}()
+
+	os.Unsetenv("GITHUB_EVENT_PATH")
+	os.Unsetenv("GITHUB_BASE_REF")
+
+	checkValue := func(tags map[string]string, key, expectedValue string) {
+		if tags[key] != expectedValue {
+			t.Fatalf("Key: %s, the actual value (%s) is different to the expected value (%s)", key, tags[key], expectedValue)
+		}
+	}
+
+	t.Run("with event file", func(t *testing.T) {
+		eventFile := "testdata/fixtures/github-event.json"
+		t.Setenv("GITHUB_EVENT_PATH", eventFile)
+		t.Setenv("GITHUB_BASE_REF", "my-base-ref") // this should be ignored in favor of the event file value
+
+		tags := extractGithubActions()
+		expectedHeadCommit := "df289512a51123083a8e6931dd6f57bb3883d4c4"
+		expectedBaseCommit := "52e0974c74d41160a03d59ddc73bb9f5adab054b"
+		expectedBaseRef := "main"
+
+		checkValue(tags, constants.GitHeadCommit, expectedHeadCommit)
+		checkValue(tags, constants.GitPrBaseCommit, expectedBaseCommit)
+		checkValue(tags, constants.GitPrBaseBranch, expectedBaseRef)
+	})
+
+	t.Run("no event file", func(t *testing.T) {
+		t.Setenv("GITHUB_BASE_REF", "my-base-ref") // this should be ignored in favor of the event file value
+
+		tags := extractGithubActions()
+		checkValue(tags, constants.GitPrBaseBranch, "my-base-ref")
+	})
+}