Copy network, pid and uts mode only if target container is running

README.md

@@ -66,13 +66,13 @@ Sometimes it's useful to change the entrypoint and/or command for a container, f
 To simulate a crashing application, use docker run to create a container that immediately exits:
 
 ```shell
-docker run busybox:1.28 /bin/sh -c "false"
+docker run --name crashing-container busybox:1.28 /bin/sh -c "false"
 ```
 
 You can use `debug-ctr debug` with `--entrypoint` and/or `--cmd` to create a copy of this container with the command changed to an interactive shell:
 
 ```shell
-debug-ctr debug --image=docker.io/alpine:latest --target=my-distroless --copy-to=my-distroless-copy --entrypoint="/.debugger/sleep" --cmd="365d"
+debug-ctr debug --image=docker.io/alpine:latest --target=crashing-container --copy-to=crashing-container-copy --entrypoint="/.debugger/sleep" --cmd="365d"
 ```
 
 Now you have an interactive shell that you can use to perform tasks like checking filesystem paths or running a container command manually.

cmd/debug.go

@@ -233,6 +233,19 @@ func createCopyContainer(ctx context.Context, debugImage, targetContainer, copyC
 	log.Printf("containerCmd: %+v", containerCmd)
 
 	target := "container:" + targetContainer
+
+	hostConfig := &container.HostConfig{
+		Binds: []string{
+			volume + ":" + "/.debugger",
+		},
+	}
+
+	if inspect.State.Running {
+		hostConfig.NetworkMode = container.NetworkMode(target)
+		hostConfig.PidMode = container.PidMode(target)
+		hostConfig.UTSMode = container.UTSMode(target)
+	}
+
 	copyContainerCreateResp, err := cli.ContainerCreate(ctx, &container.Config{
 		Image:      inspect.Image,
 		User:       inspect.Config.User,
@@ -241,14 +254,7 @@ func createCopyContainer(ctx context.Context, debugImage, targetContainer, copyC
 		Cmd:        containerCmd,
 		WorkingDir: inspect.Config.WorkingDir,
 		Labels:     inspect.Config.Labels,
-	}, &container.HostConfig{
-		Binds: []string{
-			volume + ":" + "/.debugger",
-		},
-		NetworkMode: container.NetworkMode(target),
-		PidMode:     container.PidMode(target),
-		UTSMode:     container.UTSMode(target),
-	}, nil, nil, copyContainerName)
+	}, hostConfig, nil, nil, copyContainerName)
 	if err != nil {
 		return err
 	}