Pass errors down from ProjectRunner

In preparation for being able to gracefully shutdown the HTTP server.

The existing exit code is wrapped in a new type that satisfies `error`
and lets us pull the code out for `os.Exit`.

src/app/project_runner.go

@@ -15,6 +15,14 @@ import (
 	"github.com/rs/zerolog/log"
 )
 
+type ExitError struct {
+	Code int
+}
+
+func (e *ExitError) Error() string {
+	return fmt.Sprintf("project non-zero exit code: %d", e.Code)
+}
+
 type ProjectRunner struct {
 	procConfMutex     sync.Mutex
 	project           *types.Project
@@ -47,15 +55,15 @@ func (p *ProjectRunner) init() {
 	p.initProcessLogs()
 }
 
-func (p *ProjectRunner) Run() int {
+func (p *ProjectRunner) Run() error {
 	p.runningProcesses = make(map[string]*Process)
 	runOrder := []types.ProcessConfig{}
 	err := p.project.WithProcesses([]string{}, func(process types.ProcessConfig) error {
 		runOrder = append(runOrder, process)
 		return nil
 	})
 	if err != nil {
-		log.Error().Msgf("Failed to build project run order: %s", err.Error())
+		return fmt.Errorf("failed to build project run order: %e", err)
 	}
 	var nameOrder []string
 	for _, v := range runOrder {
@@ -75,7 +83,10 @@ func (p *ProjectRunner) Run() int {
 	}
 	p.waitGroup.Wait()
 	log.Info().Msg("Project completed")
-	return p.exitCode
+	if p.exitCode != 0 {
+		err = &ExitError{p.exitCode}
+	}
+	return err
 }
 
 func (p *ProjectRunner) runProcess(config *types.ProcessConfig) {

src/app/system_test.go

@@ -146,10 +146,10 @@ func TestSystem_TestComposeChainExit(t *testing.T) {
 			t.Errorf(err.Error())
 			return
 		}
-		exitCode := runner.Run()
-		want := 42
-		if want != exitCode {
-			t.Errorf("Project.Run() = %v, want %v", exitCode, want)
+		err = runner.Run()
+		want := "project non-zero exit code: 42"
+		if want != err.Error() {
+			t.Errorf("Project.Run() = %v, want %v", err, want)
 		}
 	})
 }

src/cmd/project_runner.go

@@ -38,16 +38,16 @@ func getProjectRunner(process []string, noDeps bool, mainProcess string, mainPro
 	return runner
 }
 
-func runProject(runner *app.ProjectRunner) {
-	exitCode := 0
+func runProject(runner *app.ProjectRunner) error {
+	var err error
 	if *pcFlags.IsTuiEnabled {
-		exitCode = runTui(runner)
+		err = runTui(runner)
 	} else {
-		exitCode = runHeadless(runner)
+		err = runHeadless(runner)
 	}
 	os.Remove(*pcFlags.UnixSocketPath)
 	log.Info().Msg("Thank you for using process-compose")
-	os.Exit(exitCode)
+	return err
 }
 
 func setSignal(signalHandler func()) {
@@ -60,23 +60,22 @@ func setSignal(signalHandler func()) {
 	}()
 }
 
-func runHeadless(project *app.ProjectRunner) int {
+func runHeadless(project *app.ProjectRunner) error {
 	setSignal(func() {
 		_ = project.ShutDownProject()
 	})
-	exitCode := project.Run()
-	return exitCode
+	return project.Run()
 }
 
-func runTui(project *app.ProjectRunner) int {
+func runTui(project *app.ProjectRunner) error {
 	go startTui(project)
-	exitCode := project.Run()
+	err := project.Run()
 	if !*pcFlags.KeepTuiOn {
 		tui.Stop()
 	} else {
 		tui.Wait()
 	}
-	return exitCode
+	return err
 }
 
 func startTui(runner app.IProject) {

src/cmd/root.go

@@ -36,18 +36,18 @@ var (
 			pcFlags.PcThemeChanged = cmd.Flags().Changed(flagTheme)
 			pcFlags.SortColumnChanged = cmd.Flags().Changed(flagSort)
 		},
-		RunE: run,
+		Run: run,
 	}
 )
 
-func run(cmd *cobra.Command, args []string) error {
+func run(cmd *cobra.Command, args []string) {
 	defer func() {
 		_ = logFile.Close()
 	}()
 	runner := getProjectRunner([]string{}, false, "", []string{})
 	startHttpServerIfEnabled(!*pcFlags.IsTuiEnabled, runner)
-	runProject(runner)
-	return nil
+	err := runProject(runner)
+	handleErrorAndExit(err)
 }
 
 // Execute adds all child commands to the root command and sets flags appropriately.
@@ -137,6 +137,17 @@ func setupLogger() *os.File {
 	return file
 }
 
+// Logs and exits with a non-zero code if there are any errors.
+func handleErrorAndExit(err error) {
+	if err != nil {
+		log.Error().Err(err)
+		if exitErr, ok := err.(*app.ExitError); ok {
+			os.Exit(exitErr.Code)
+		}
+		os.Exit(1)
+	}
+}
+
 func startHttpServerIfEnabled(useLogger bool, runner *app.ProjectRunner) {
 	if !*pcFlags.NoServer {
 		if *pcFlags.IsUnixSocket {

src/cmd/run.go

@@ -40,7 +40,8 @@ Command line arguments, provided after --, are passed to the PROCESS.`,
 		)
 
 		startHttpServerIfEnabled(false, runner)
-		runProject(runner)
+		err := runProject(runner)
+		handleErrorAndExit(err)
 	},
 }
 

src/cmd/up.go

@@ -15,7 +15,8 @@ will start them and their dependencies only`,
 	Run: func(cmd *cobra.Command, args []string) {
 		runner := getProjectRunner(args, *pcFlags.NoDependencies, "", []string{})
 		startHttpServerIfEnabled(!*pcFlags.IsTuiEnabled, runner)
-		runProject(runner)
+		err := runProject(runner)
+		handleErrorAndExit(err)
 	},
 }