podman unshare: add --rootless-cni to join the ns

Add a new --rootless-cni option to podman unshare to also join the
rootless-cni network namespace. This is useful if you want to connect
to a rootless container via IP address. This is only possible from the
rootless-cni namespace and not from the host namespace. This option also
helps to debug problems in the rootless-cni namespace.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

4 files changed, 26 insertions, 9 deletions

diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index bcab617af..f695d32fd 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -88,7 +88,7 @@ type ContainerEngine interface {
 	SecretRm(ctx context.Context, nameOrID []string, opts SecretRmOptions) ([]*SecretRmReport, error)
 	Shutdown(ctx context.Context)
 	SystemDf(ctx context.Context, options SystemDfOptions) (*SystemDfReport, error)
-	Unshare(ctx context.Context, args []string) error
+	Unshare(ctx context.Context, args []string, options SystemUnshareOptions) error
 	Version(ctx context.Context) (*SystemVersionReport, error)
 	VolumeCreate(ctx context.Context, opts VolumeCreateOptions) (*IDOrNameResponse, error)
 	VolumeExists(ctx context.Context, namesOrID string) (*BoolReport, error)
diff --git a/pkg/domain/entities/system.go b/pkg/domain/entities/system.go
index 1a671d59e..31a6185dc 100644
--- a/pkg/domain/entities/system.go
+++ b/pkg/domain/entities/system.go
@@ -98,6 +98,11 @@ type SystemVersionReport struct {
 	Server *define.Version `json:",omitempty"`
 }
 
+// SystemUnshareOptions describes the options for the unshare command
+type SystemUnshareOptions struct {
+	RootlessCNI bool
+}
+
 type ComponentVersion struct {
 	types.Version
 }
diff --git a/pkg/domain/infra/abi/system.go b/pkg/domain/infra/abi/system.go
index a3e753384..f87f9e370 100644
--- a/pkg/domain/infra/abi/system.go
+++ b/pkg/domain/infra/abi/system.go
@@ -390,13 +390,25 @@ func unshareEnv(graphroot, runroot string) []string {
 		fmt.Sprintf("CONTAINERS_RUNROOT=%s", runroot))
 }
 
-func (ic *ContainerEngine) Unshare(ctx context.Context, args []string) error {
-	cmd := exec.Command(args[0], args[1:]...)
-	cmd.Env = unshareEnv(ic.Libpod.StorageConfig().GraphRoot, ic.Libpod.StorageConfig().RunRoot)
-	cmd.Stdin = os.Stdin
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-	return cmd.Run()
+func (ic *ContainerEngine) Unshare(ctx context.Context, args []string, options entities.SystemUnshareOptions) error {
+	unshare := func() error {
+		cmd := exec.Command(args[0], args[1:]...)
+		cmd.Env = unshareEnv(ic.Libpod.StorageConfig().GraphRoot, ic.Libpod.StorageConfig().RunRoot)
+		cmd.Stdin = os.Stdin
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		return cmd.Run()
+	}
+
+	if options.RootlessCNI {
+		rootlesscni, err := ic.Libpod.GetRootlessCNINetNs(true)
+		if err != nil {
+			return err
+		}
+		defer rootlesscni.Cleanup(ic.Libpod)
+		return rootlesscni.Do(unshare)
+	}
+	return unshare()
 }
 
 func (ic ContainerEngine) Version(ctx context.Context) (*entities.SystemVersionReport, error) {
diff --git a/pkg/domain/infra/tunnel/system.go b/pkg/domain/infra/tunnel/system.go
index d2c5063c9..7400d3771 100644
--- a/pkg/domain/infra/tunnel/system.go
+++ b/pkg/domain/infra/tunnel/system.go
@@ -28,7 +28,7 @@ func (ic *ContainerEngine) SystemDf(ctx context.Context, options entities.System
 	return system.DiskUsage(ic.ClientCtx, nil)
 }
 
-func (ic *ContainerEngine) Unshare(ctx context.Context, args []string) error {
+func (ic *ContainerEngine) Unshare(ctx context.Context, args []string, options entities.SystemUnshareOptions) error {
 	return errors.New("unshare is not supported on remote clients")
 }