pkg/kubelet/user/userns: remove, use moby/sys/userns

The code from github.com/opencontainers/runc/libcontainer/userns package
was moved into github.com/moby/sys/user and github.com/moby/sys/userns
(see [1]), and the runc package is now deprecated in favor of moby/sys
(see [2]).

In addition, moby/sys/userns now has a non-Linux implementation, so
pkg/kubelet/user/userns package (introduced in commit 2e999ff to make a
non-Linux implementation) is not really needed anymore.

Let's switch to moby/sys/userns, and remove the package.

[1]: https://github.com/moby/sys/releases/tag/userns%2Fv0.1.0
[2]: opencontainers/runc#4350

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

go.mod

@@ -44,6 +44,7 @@ require (
 	github.com/libopenstorage/openstorage v1.0.0
 	github.com/lithammer/dedent v1.1.0
 	github.com/moby/ipvs v1.1.0
+	github.com/moby/sys/userns v0.1.0
 	github.com/mrunalp/fileutils v0.5.1
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822
 	github.com/onsi/ginkgo/v2 v2.19.0

go.sum

@@ -396,6 +396,8 @@ github.com/moby/spdystream v0.5.0 h1:7r0J1Si3QO/kjRitvSLVVFUjxMEb/YLj6S9FF62JBCU
 github.com/moby/spdystream v0.5.0/go.mod h1:xBAYlnt/ay+11ShkdFKNAG7LsyK/tmNBVvVOwrfMgdI=
 github.com/moby/sys/mountinfo v0.7.2 h1:1shs6aH5s4o5H2zQLn796ADW1wMrIwHsyJ2v9KouLrg=
 github.com/moby/sys/mountinfo v0.7.2/go.mod h1:1YOa8w8Ih7uW0wALDUgT1dTTSBrZ+HiBLGws92L2RU4=
+github.com/moby/sys/userns v0.1.0 h1:tVLXkFOxVu9A64/yh59slHVv9ahO9UIev4JZusOLG/g=
+github.com/moby/sys/userns v0.1.0/go.mod h1:IHUYgu/kao6N8YZlp9Cf444ySSvCmDlmzUcYfDHOl28=
 github.com/moby/term v0.5.0 h1:xt8Q1nalod/v7BqbG21f8mQPqH+xAaC9C3N3wfWbVP0=
 github.com/moby/term v0.5.0/go.mod h1:8FzsFHVUBGZdbDsJw/ot+X+d5HLUbvklYLJ9uGfcI3Y=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=

pkg/kubelet/cm/container_manager_linux.go

@@ -34,6 +34,7 @@ import (
 	"k8s.io/mount-utils"
 	utilpath "k8s.io/utils/path"
 
+	inuserns "github.com/moby/sys/userns"
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/apimachinery/pkg/types"
@@ -63,7 +64,6 @@ import (
 	"k8s.io/kubernetes/pkg/kubelet/pluginmanager/cache"
 	"k8s.io/kubernetes/pkg/kubelet/stats/pidlimit"
 	"k8s.io/kubernetes/pkg/kubelet/status"
-	"k8s.io/kubernetes/pkg/kubelet/userns/inuserns"
 	"k8s.io/kubernetes/pkg/kubelet/util/swap"
 	schedulerframework "k8s.io/kubernetes/pkg/scheduler/framework"
 	"k8s.io/kubernetes/pkg/util/oom"

pkg/kubelet/kubelet.go

@@ -45,6 +45,7 @@ import (
 	utilfs "k8s.io/kubernetes/pkg/util/filesystem"
 	netutils "k8s.io/utils/net"
 
+	inuserns "github.com/moby/sys/userns"
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/fields"
@@ -112,7 +113,6 @@ import (
 	"k8s.io/kubernetes/pkg/kubelet/token"
 	kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
 	"k8s.io/kubernetes/pkg/kubelet/userns"
-	"k8s.io/kubernetes/pkg/kubelet/userns/inuserns"
 	"k8s.io/kubernetes/pkg/kubelet/util"
 	"k8s.io/kubernetes/pkg/kubelet/util/manager"
 	"k8s.io/kubernetes/pkg/kubelet/util/queue"

pkg/kubelet/util/swap/swap_util.go

@@ -24,9 +24,9 @@ import (
 	"strings"
 	"sync"
 
+	inuserns "github.com/moby/sys/userns"
 	"k8s.io/apimachinery/pkg/util/version"
 	"k8s.io/klog/v2"
-	"k8s.io/kubernetes/pkg/kubelet/userns/inuserns"
 	utilkernel "k8s.io/kubernetes/pkg/util/kernel"
 	"k8s.io/mount-utils"
 )