fix: filter out successful pipelineruns for /ok-to-test /retest

When running /ok-to-test or /retest all the pipelineruns are
rerun over again. These pipeline runs instead should be skipped.
When parsing for pipelineruns created for a Repository, we
check whether any of the matched pipelineruns have been triggered
by either the ok-to-test or retest event types. If they have, then
we filter them out of the matched pipelineruns.

Author: waveywaves

pkg/pipelineascode/match.go

@@ -18,6 +18,7 @@ import (
 	"github.com/openshift-pipelines/pipelines-as-code/pkg/templates"
 	tektonv1 "github.com/tektoncd/pipeline/pkg/apis/pipeline/v1"
 	"go.uber.org/zap"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 func (p *PacRun) matchRepoPR(ctx context.Context) ([]matcher.Match, *v1alpha1.Repository, error) {
@@ -165,6 +166,77 @@ is that what you want? make sure you use -n when generating the secret, eg: echo
 	return repo, nil
 }
 
+// isAlreadyExecuted checks if the pipeline has already been executed for the given SHA and PR number.
+func (p *PacRun) isAlreadyExecuted(ctx context.Context, match matcher.Match) (bool, error) {
+	// Get existing PipelineRuns for this repository that match the current SHA and PR number
+	labelSelector := fmt.Sprintf("%s=%s,%s=%d,%s=%s",
+		apipac.SHA, p.event.SHA,
+		apipac.PullRequest, p.event.PullRequestNumber,
+		apipac.Repository, match.Repo.Name)
+
+	existingPRs, err := p.run.Clients.Tekton.TektonV1().PipelineRuns(match.Repo.Namespace).List(ctx, metav1.ListOptions{
+		LabelSelector: labelSelector,
+	})
+	if err != nil {
+		return false, fmt.Errorf("failed to get existing pipelineruns: %w", err)
+	}
+
+	// check for any successful runs for this specific pipeline
+	targetPRName := strings.TrimSuffix(match.PipelineRun.GetGenerateName(), "-")
+	if targetPRName == "" {
+		targetPRName = match.PipelineRun.GetName()
+	}
+
+	for _, pr := range existingPRs.Items {
+		// Skip pipeline runs that are still running or not done
+		if !pr.IsDone() || pr.Status.CompletionTime == nil {
+			continue
+		}
+
+		// if it's the same pipeline
+		existingPRName := ""
+		if originalPRName, ok := pr.GetAnnotations()[apipac.OriginalPRName]; ok {
+			existingPRName = originalPRName
+		} else {
+			continue
+		}
+
+		// Only skip if the pipeline was successful
+		if existingPRName == targetPRName && pr.Status.GetCondition("Succeeded").IsTrue() {
+			msg := fmt.Sprintf("Skipping pipeline run %s as it has already completed successfully for SHA %s on PR #%d",
+				targetPRName, p.event.SHA, p.event.PullRequestNumber)
+			p.eventEmitter.EmitMessage(match.Repo, zap.InfoLevel, "RepositorySkippingPipelineRun", msg)
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+// filterAlreadySuccessfulPipelines filters out pipeline runs that have already been executed successfully.
+func (p *PacRun) filterAlreadySuccessfulPipelines(ctx context.Context, matchedPRs []matcher.Match) []matcher.Match {
+	filteredMatches := []matcher.Match{}
+	for _, match := range matchedPRs {
+		alreadyExecuted, err := p.isAlreadyExecuted(ctx, match)
+		if err != nil {
+			prName := match.PipelineRun.GetGenerateName()
+			if prName == "" {
+				prName = match.PipelineRun.GetName()
+			}
+			msg := fmt.Sprintf("Error checking if pipeline %s was already executed: %v",
+				prName, err)
+			p.eventEmitter.EmitMessage(match.Repo, zap.WarnLevel, "RepositoryCheckExecution", msg)
+			filteredMatches = append(filteredMatches, match)
+			continue
+		}
+
+		if !alreadyExecuted {
+			filteredMatches = append(filteredMatches, match)
+		}
+	}
+	return filteredMatches
+}
+
 // getPipelineRunsFromRepo fetches pipelineruns from git repository and prepare them for creation.
 func (p *PacRun) getPipelineRunsFromRepo(ctx context.Context, repo *v1alpha1.Repository) ([]matcher.Match, error) {
 	provenance := "source"
@@ -262,6 +334,11 @@ func (p *PacRun) getPipelineRunsFromRepo(ctx context.Context, repo *v1alpha1.Rep
 			}
 			return nil, nil
 		}
+
+		// filter out pipelines that have already been executed successfully
+		if p.event.EventType == opscomments.RetestAllCommentEventType.String() || p.event.EventType == opscomments.OkToTestCommentEventType.String() {
+			matchedPRs = p.filterAlreadySuccessfulPipelines(ctx, matchedPRs)
+		}
 	}
 
 	// if the event is a comment event, but we don't have any match from the keys.OnComment then do the ACL checks again