From 8664311cad8648c8d1db70fa3e56e1cf51ee1d3b Mon Sep 17 00:00:00 2001
From: Arjun Raja Yogidas <arjunry@amazon.com>
Date: Tue, 18 Feb 2025 23:42:31 +0000
Subject: [PATCH] feat: add signal option to containerRestart

Signed-off-by: Arjun Raja Yogidas <arjunry@amazon.com>
---
 cmd/nerdctl/container/container_restart.go    | 12 ++++++++
 .../container/container_restart_linux_test.go | 29 +++++++++++++++++++
 docs/command-reference.md                     |  2 ++
 pkg/api/types/container_types.go              |  2 ++
 pkg/cmd/container/restart.go                  |  2 +-
 5 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/cmd/nerdctl/container/container_restart.go b/cmd/nerdctl/container/container_restart.go
index b1875a77853..60c0f100e41 100644
--- a/cmd/nerdctl/container/container_restart.go
+++ b/cmd/nerdctl/container/container_restart.go
@@ -38,6 +38,7 @@ func NewRestartCommand() *cobra.Command {
 		SilenceErrors:     true,
 	}
 	restartCommand.Flags().UintP("time", "t", 10, "Seconds to wait for stop before killing it")
+	restartCommand.Flags().StringP("signal", "s", "", "Signal to send to stop the container, before killing it")
 	return restartCommand
 }
 
@@ -58,10 +59,21 @@ func processContainerRestartOptions(cmd *cobra.Command) (types.ContainerRestartO
 		timeout = &t
 	}
 
+	var signal string
+	if cmd.Flags().Changed("signal") {
+		// Signal to send to stop the container, before killing it
+		sig, err := cmd.Flags().GetString("signal")
+		if err != nil {
+			return types.ContainerRestartOptions{}, err
+		}
+		signal = sig
+	}
+
 	return types.ContainerRestartOptions{
 		Stdout:  cmd.OutOrStdout(),
 		GOption: globalOptions,
 		Timeout: timeout,
+		Signal:  signal,
 	}, err
 }
 
diff --git a/cmd/nerdctl/container/container_restart_linux_test.go b/cmd/nerdctl/container/container_restart_linux_test.go
index 3565f9f11ad..12a011fa751 100644
--- a/cmd/nerdctl/container/container_restart_linux_test.go
+++ b/cmd/nerdctl/container/container_restart_linux_test.go
@@ -121,3 +121,32 @@ func TestRestartWithTime(t *testing.T) {
 	// ensure that stop took at least 5 seconds
 	assert.Assert(t, timePostRestart.Sub(timePreRestart) >= time.Second*5)
 }
+
+func TestRestartWithSignal(t *testing.T) {
+	t.Parallel()
+	base := testutil.NewBase(t)
+	tID := testutil.Identifier(t)
+
+	base.Cmd("run", "-d", "--name", tID, testutil.AlpineImage, "sh", "-c", `
+		trap 'echo "Received SIGUSR1"; exit 0' SIGUSR1
+		echo "Starting"
+		while true; do
+			sleep 1
+		done
+	`).AssertOK()
+	defer base.Cmd("rm", "-f", tID).Run()
+
+	base.EnsureContainerStarted(tID)
+
+	inspect := base.InspectContainer(tID)
+	initialPid := inspect.State.Pid
+
+	base.Cmd("restart", "--signal", "SIGUSR1", tID).AssertOK()
+	base.EnsureContainerStarted(tID)
+
+	newInspect := base.InspectContainer(tID)
+	newPid := newInspect.State.Pid
+
+	assert.Assert(t, initialPid != newPid, "Container PID should have changed after restart")
+
+}
diff --git a/docs/command-reference.md b/docs/command-reference.md
index 73e0c451d0d..898bd2a4069 100644
--- a/docs/command-reference.md
+++ b/docs/command-reference.md
@@ -573,6 +573,7 @@ Flags:
 
 - :whale: `-t, --time=SECONDS`: Seconds to wait for stop before killing it (default "10")
   - Tips: If the init process in container is exited after receiving SIGTERM or exited before the time you specified, the container will be exited immediately
+- :whale: `-s, --signal=SIGNAL`: Signal to send to the container (e.g. SIGINT).
 
 ### :whale: nerdctl start
 
@@ -597,6 +598,7 @@ Flags:
 
 - :whale: `-t, --time=SECONDS`: Seconds to wait for stop before killing it (default "10")
   - Tips: If the init process in container is exited after receiving SIGTERM or exited before the time you specified, the container will be exited immediately
+- :whale: `-s, --signal=SIGNAL`: Signal to send to the container (e.g. SIGINT).
 
 ### :whale: nerdctl update
 
diff --git a/pkg/api/types/container_types.go b/pkg/api/types/container_types.go
index d38a0e5da11..3d0ae773ce1 100644
--- a/pkg/api/types/container_types.go
+++ b/pkg/api/types/container_types.go
@@ -286,6 +286,8 @@ type ContainerRestartOptions struct {
 	GOption GlobalCommandOptions
 	// Time to wait after sending a SIGTERM and before sending a SIGKILL.
 	Timeout *time.Duration
+	// Signal to send to stop the container, before sending SIGKILL
+	Signal string
 }
 
 // ContainerPauseOptions specifies options for `nerdctl (container) pause`.
diff --git a/pkg/cmd/container/restart.go b/pkg/cmd/container/restart.go
index 1be264e056f..6b60b082236 100644
--- a/pkg/cmd/container/restart.go
+++ b/pkg/cmd/container/restart.go
@@ -35,7 +35,7 @@ func Restart(ctx context.Context, client *containerd.Client, containers []string
 			if found.MatchCount > 1 {
 				return fmt.Errorf("multiple IDs found with provided prefix: %s", found.Req)
 			}
-			if err := containerutil.Stop(ctx, found.Container, options.Timeout, "SIGTERM"); err != nil {
+			if err := containerutil.Stop(ctx, found.Container, options.Timeout, options.Signal); err != nil {
 				return err
 			}
 			if err := containerutil.Start(ctx, found.Container, false, client, ""); err != nil {