reduce cyclomatic complexity

cli/docker.go

@@ -82,8 +82,9 @@ const (
 	// with UID/GID 1000 will be mapped to `UserNamespaceOffset` + 1000
 	// on the host. Changing this value will result in improper mappings
 	// on existing containers.
-	UserNamespaceOffset = 100000
-	devDir              = "/dev"
+	UserNamespaceOffset    = 100000
+	devDir                 = "/dev"
+	defaultShutdownTimeout = time.Minute
 )
 
 var (
@@ -355,7 +356,7 @@ func dockerCmd(ch chan func() error) *cobra.Command {
 	cliflag.IntVarP(cmd.Flags(), &flags.cpus, "cpus", "", EnvCPUs, 0, "Number of CPUs to allocate inner container. e.g. 2")
 	cliflag.IntVarP(cmd.Flags(), &flags.memory, "memory", "", EnvMemory, 0, "Max memory to allocate to the inner container in bytes.")
 	cliflag.BoolVarP(cmd.Flags(), &flags.disableIDMappedMount, "disable-idmapped-mount", "", EnvDisableIDMappedMount, false, "Disable idmapped mounts in sysbox. Note that you may need an alternative (e.g. shiftfs).")
-	cliflag.DurationVarP(cmd.Flags(), &flags.shutdownTimeout, "shutdown-timeout", "", EnvShutdownTimeout, time.Minute, "Duration after which envbox will be forcefully terminated.")
+	cliflag.DurationVarP(cmd.Flags(), &flags.shutdownTimeout, "shutdown-timeout", "", EnvShutdownTimeout, defaultShutdownTimeout, "Duration after which envbox will be forcefully terminated.")
 
 	// Test flags.
 	cliflag.BoolVarP(cmd.Flags(), &flags.noStartupLogs, "no-startup-log", "", "", false, "Do not log startup logs. Useful for testing.")
@@ -732,35 +733,38 @@ func runDockerCVM(ctx context.Context, log slog.Logger, client dockerutil.Docker
 		return xerrors.Errorf("exec inspect: %w", err)
 	}
 
-	shutdownCh <- func() error {
-		log.Debug(ctx, "killing container", slog.F("bootstrap_pid", bootstrapPID))
+	shutdownCh <- killBootstrapCmd(ctx, log, bootstrapPID, bootstrapExec.ID, client, flags.shutdownTimeout)
 
-		timeout := time.Minute
-		if flags.shutdownTimeout != time.Minute {
-			timeout = flags.shutdownTimeout
-			log.Debug(ctx, "using custom shutdown timeout", slog.F("timeout", timeout.String()))
-		}
+	return nil
+}
+
+// KillBootstrapCmd is the command we run when we receive a signal
+// to kill the envbox container.
+func killBootstrapCmd(ctx context.Context, log slog.Logger, pid int, execID string, client dockerutil.DockerClient, timeout time.Duration) func() error {
+	return func() error {
+		log.Debug(ctx, "killing container",
+			slog.F("bootstrap_pid", pid),
+			slog.F("timeout", timeout.String()),
+		)
 
 		ctx, cancel := context.WithTimeout(ctx, timeout)
 		defer cancel()
 		// The PID returned is the PID _outside_ the container...
 		//nolint:gosec
-		out, err := exec.CommandContext(ctx, "kill", "-TERM", strconv.Itoa(bootstrapPID)).CombinedOutput()
+		out, err := exec.CommandContext(ctx, "kill", "-TERM", strconv.Itoa(pid)).CombinedOutput()
 		if err != nil {
 			return xerrors.Errorf("kill bootstrap process (%s): %w", out, err)
 		}
 
 		log.Debug(ctx, "sent kill signal waiting for process to exit")
-		err = dockerutil.WaitForExit(ctx, client, bootstrapExec.ID)
+		err = dockerutil.WaitForExit(ctx, client, execID)
 		if err != nil {
 			return xerrors.Errorf("wait for exit: %w", err)
 		}
 
 		log.Debug(ctx, "bootstrap process successfully exited")
 		return nil
 	}
-
-	return nil
 }
 
 //nolint:revive