[Refactor] Move generateSharingPIDOpts from cmd to pkg/containerutil

cmd/nerdctl/run.go

@@ -43,7 +43,6 @@ import (
 	"github.com/containerd/nerdctl/pkg/clientutil"
 	"github.com/containerd/nerdctl/pkg/cmd/container"
 	"github.com/containerd/nerdctl/pkg/cmd/image"
-	"github.com/containerd/nerdctl/pkg/containerutil"
 	"github.com/containerd/nerdctl/pkg/defaults"
 	"github.com/containerd/nerdctl/pkg/errutil"
 	"github.com/containerd/nerdctl/pkg/idgen"
@@ -56,7 +55,6 @@ import (
 	"github.com/containerd/nerdctl/pkg/netutil"
 	"github.com/containerd/nerdctl/pkg/platformutil"
 	"github.com/containerd/nerdctl/pkg/referenceutil"
-	"github.com/containerd/nerdctl/pkg/rootlessutil"
 	"github.com/containerd/nerdctl/pkg/strutil"
 	"github.com/containerd/nerdctl/pkg/taskutil"
 	dopts "github.com/docker/cli/opts"
@@ -1237,49 +1235,6 @@ func withOSEnv(envs []string) ([]string, error) {
 	return newEnvs, nil
 }
 
-func generateSharingPIDOpts(ctx context.Context, targetCon containerd.Container) ([]oci.SpecOpts, error) {
-	opts := make([]oci.SpecOpts, 0)
-
-	task, err := targetCon.Task(ctx, nil)
-	if err != nil {
-		return nil, err
-	}
-	status, err := task.Status(ctx)
-	if err != nil {
-		return nil, err
-	}
-
-	if status.Status != containerd.Running {
-		return nil, fmt.Errorf("shared container is not running")
-	}
-
-	spec, err := targetCon.Spec(ctx)
-	if err != nil {
-		return nil, err
-	}
-
-	isHost := true
-	for _, n := range spec.Linux.Namespaces {
-		if n.Type == specs.PIDNamespace {
-			isHost = false
-		}
-	}
-	if isHost {
-		opts = append(opts, oci.WithHostNamespace(specs.PIDNamespace))
-		if rootlessutil.IsRootless() {
-			opts = append(opts, containerutil.WithBindMountHostProcfs)
-		}
-	} else {
-		ns := specs.LinuxNamespace{
-			Type: specs.PIDNamespace,
-			Path: fmt.Sprintf("/proc/%d/ns/pid", task.Pid()),
-		}
-		opts = append(opts, oci.WithLinuxNamespace(ns))
-	}
-
-	return opts, nil
-}
-
 // generateEnvs combines environment variables from `--env-file` and `--env`.
 // Pass an empty slice if any arg is not used.
 func generateEnvs(envFile []string, env []string) ([]string, error) {

cmd/nerdctl/run_linux.go

@@ -297,7 +297,7 @@ func generatePIDOpts(ctx context.Context, client *containerd.Client, pid string)
 					return fmt.Errorf("multiple IDs found with provided prefix: %s", found.Req)
 				}
 
-				o, err := generateSharingPIDOpts(ctx, found.Container)
+				o, err := containerutil.GenerateSharingPIDOpts(ctx, found.Container)
 				if err != nil {
 					return err
 				}

cmd/nerdctl/start.go

@@ -38,7 +38,6 @@ import (
 	"github.com/containerd/nerdctl/pkg/netutil/nettype"
 	"github.com/containerd/nerdctl/pkg/taskutil"
 	"github.com/opencontainers/runtime-spec/specs-go"
-
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 )
@@ -250,7 +249,7 @@ func reconfigPIDContainer(ctx context.Context, c containerd.Container, client *c
 		return err
 	}
 
-	opts, err := generateSharingPIDOpts(ctx, targetCon)
+	opts, err := containerutil.GenerateSharingPIDOpts(ctx, targetCon)
 	if err != nil {
 		return err
 	}

pkg/containerutil/containerutil.go

@@ -30,6 +30,7 @@ import (
 	"github.com/containerd/containerd/oci"
 	"github.com/containerd/containerd/runtime/restart"
 	"github.com/containerd/nerdctl/pkg/portutil"
+	"github.com/containerd/nerdctl/pkg/rootlessutil"
 	"github.com/opencontainers/runtime-spec/specs-go"
 )
 
@@ -129,3 +130,47 @@ func WithBindMountHostProcfs(_ context.Context, _ oci.Client, _ *containers.Cont
 	s.Linux.ReadonlyPaths = newROP
 	return nil
 }
+
+// GenerateSharingPIDOpts returns the oci.SpecOpts that shares the host linux namespace from `targetCon`
+// If `targetCon` doesn't have a `PIDNamespace`, a new one is generated from its `Pid`.
+func GenerateSharingPIDOpts(ctx context.Context, targetCon containerd.Container) ([]oci.SpecOpts, error) {
+	opts := make([]oci.SpecOpts, 0)
+
+	task, err := targetCon.Task(ctx, nil)
+	if err != nil {
+		return nil, err
+	}
+	status, err := task.Status(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	if status.Status != containerd.Running {
+		return nil, fmt.Errorf("shared container is not running")
+	}
+
+	spec, err := targetCon.Spec(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	isHost := true
+	for _, n := range spec.Linux.Namespaces {
+		if n.Type == specs.PIDNamespace {
+			isHost = false
+		}
+	}
+	if isHost {
+		opts = append(opts, oci.WithHostNamespace(specs.PIDNamespace))
+		if rootlessutil.IsRootless() {
+			opts = append(opts, WithBindMountHostProcfs)
+		}
+	} else {
+		ns := specs.LinuxNamespace{
+			Type: specs.PIDNamespace,
+			Path: fmt.Sprintf("/proc/%d/ns/pid", task.Pid()),
+		}
+		opts = append(opts, oci.WithLinuxNamespace(ns))
+	}
+	return opts, nil
+}