observe: allow DEBUG logs via env vars

internal/app/app.go

@@ -101,7 +101,7 @@ func Run(ctx context.Context, params RunParams) error {
 				return nil
 			}
 
-			logger.Info("Command received", "cmd", cmd.Name())
+			logger.Debug("Command received", "cmd", cmd.Name())
 			switch c := cmd.(type) {
 			case terminal.CommandStartDestination:
 				mp.StartDestination(c.URL)
@@ -113,9 +113,11 @@ func Run(ctx context.Context, params RunParams) error {
 		case <-uiUpdateT.C:
 			updateUI()
 		case serverState := <-srv.C():
+			logger.Debug("Server state received", "state", serverState)
 			applyServerState(serverState, state)
 			updateUI()
 		case mpState := <-mp.C():
+			logger.Debug("Multiplexer state received", "state", mpState)
 			destErrors := applyMultiplexerState(mpState, state)
 
 			for _, destError := range destErrors {

internal/testhelpers/logging.go

@@ -12,5 +12,10 @@ func NewNopLogger() *slog.Logger {
 
 // NewTestLogger returns a logger that writes to stderr.
 func NewTestLogger() *slog.Logger {
-	return slog.New(slog.NewTextHandler(os.Stderr, nil))
+	var handlerOpts slog.HandlerOptions
+	// RUNNER_DEBUG is used in the GitHub actions runner to enable debug logging.
+	if os.Getenv("DEBUG") != "" || os.Getenv("RUNNER_DEBUG") != "" {
+		handlerOpts.Level = slog.LevelDebug
+	}
+	return slog.New(slog.NewTextHandler(os.Stderr, &handlerOpts))
 }

main.go

@@ -148,5 +148,9 @@ func buildLogger(cfg config.LogFile) (*slog.Logger, error) {
 		return nil, fmt.Errorf("error opening log file: %w", err)
 	}
 
-	return slog.New(slog.NewTextHandler(fptr, nil)), nil
+	var handlerOpts slog.HandlerOptions
+	if os.Getenv("OCTO_DEBUG") != "" {
+		handlerOpts.Level = slog.LevelDebug
+	}
+	return slog.New(slog.NewTextHandler(fptr, &handlerOpts)), nil
 }