Add single-pipeline run entrypoint

internal/app/run.go

@@ -21,6 +21,14 @@ type RunOptions struct {
 	Notifier     notify.Notifier
 }
 
+type RunPipelineOptions struct {
+	ConfigPath string
+	PipelineID string
+	DryRun     bool
+	Force      bool
+	Notifier   notify.Notifier
+}
+
 func Run(ctx context.Context, options RunOptions) error {
 	if err := ValidateOutputFormat(options.OutputFormat); err != nil {
 		return err
@@ -40,12 +48,47 @@ func Run(ctx context.Context, options RunOptions) error {
 	return runConfig(ctx, cfg, options)
 }
 
+func RunPipeline(ctx context.Context, options RunPipelineOptions) (RunReport, error) {
+	if err := ctx.Err(); err != nil {
+		return RunReport{}, err
+	}
+
+	configPath := options.ConfigPath
+	if configPath == "" {
+		configPath = config.DefaultConfigPath
+	}
+	cfg, err := config.LoadFile(configPath)
+	if err != nil {
+		return RunReport{}, err
+	}
+	return runPipelineConfig(ctx, cfg, options)
+}
+
 func runConfig(ctx context.Context, cfg config.Config, options RunOptions) error {
 	return runConfigWithBackendFactory(ctx, cfg, options, newBackendFactoryWithEnvironment)
 }
 
 type backendFactoryProvider func(config.Environment) *backendFactory
 
+func runPipelineConfig(ctx context.Context, cfg config.Config, options RunPipelineOptions) (RunReport, error) {
+	return runPipelineConfigWithBackendFactory(ctx, cfg, options, newBackendFactoryWithEnvironment)
+}
+
+func runPipelineConfigWithBackendFactory(ctx context.Context, cfg config.Config, options RunPipelineOptions, provider backendFactoryProvider) (RunReport, error) {
+	pipeline, ok := findPipeline(cfg, options.PipelineID)
+	if !ok {
+		return RunReport{}, PipelineNotFoundError{ID: options.PipelineID}
+	}
+	return buildRunReportWithBackendFactory(ctx, config.Config{
+		Secrets:   cfg.Secrets,
+		Pipelines: []config.Pipeline{pipeline},
+	}, RunOptions{
+		DryRun:   options.DryRun,
+		Force:    options.Force,
+		Notifier: options.Notifier,
+	}, provider)
+}
+
 func runConfigWithBackendFactory(ctx context.Context, cfg config.Config, options RunOptions, provider backendFactoryProvider) error {
 	report, err := buildRunReportWithBackendFactory(ctx, cfg, options, provider)
 	if err != nil && !IsPartialResultError(err) {