From 7bf30d7bf13852d1f2b493817489d37170d2b8a4 Mon Sep 17 00:00:00 2001
From: Michael Crosby <crosbymichael@gmail.com>
Date: Wed, 6 Nov 2019 11:39:36 -0500
Subject: [PATCH] Rename playground to cgctl
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
---
.gitignore | 2 +-
cmd/cgctl/main.go | 120 +++++++++++++++++++++++++++++++++
cmd/cgroups-playground/main.go | 54 ---------------
v2/errors.go | 3 +-
v2/manager.go | 76 ++++++++++++++++++---
v2/paths.go | 14 ----
6 files changed, 189 insertions(+), 80 deletions(-)
create mode 100644 cmd/cgctl/main.go
delete mode 100644 cmd/cgroups-playground/main.go
diff --git a/.gitignore b/.gitignore
index 23495f5f..54f3c5db 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
example/example
-cmd/cgroups-playground/cgroups-playground
+cmd/cgctl
diff --git a/cmd/cgctl/main.go b/cmd/cgctl/main.go
new file mode 100644
index 00000000..27ceb01c
--- /dev/null
+++ b/cmd/cgctl/main.go
@@ -0,0 +1,120 @@
+/*
+ Copyright The containerd Authors.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+package main
+
+import (
+ "fmt"
+ "os"
+
+ v2 "github.com/containerd/cgroups/v2"
+ "github.com/sirupsen/logrus"
+ "github.com/urfave/cli"
+)
+
+func main() {
+ app := cli.NewApp()
+ app.Name = "cgctl"
+ app.Version = "1"
+ app.Usage = "cgroup v2 management tool"
+ app.Flags = []cli.Flag{
+ cli.BoolFlag{
+ Name: "debug",
+ Usage: "enable debug output in the logs",
+ },
+ cli.StringFlag{
+ Name: "mountpoint",
+ Usage: "cgroup mountpoint",
+ Value: "/sys/fs/cgroup",
+ },
+ }
+ app.Commands = []cli.Command{
+ newCommand,
+ delCommand,
+ listCommand,
+ }
+ app.Before = func(clix *cli.Context) error {
+ if clix.GlobalBool("debug") {
+ logrus.SetLevel(logrus.DebugLevel)
+ }
+ return nil
+ }
+ if err := app.Run(os.Args); err != nil {
+ fmt.Fprintln(os.Stderr, err)
+ os.Exit(1)
+ }
+}
+
+var newCommand = cli.Command{
+ Name: "new",
+ Usage: "create a new cgroup",
+ Flags: []cli.Flag{
+ cli.BoolFlag{
+ Name: "enable",
+ Usage: "enable the controllers for the group",
+ },
+ },
+ Action: func(clix *cli.Context) error {
+ path := clix.Args().First()
+ c, err := v2.NewManager(clix.GlobalString("mountpoint"), path, nil)
+ if err != nil {
+ return err
+ }
+ if clix.Bool("enable") {
+ controllers, err := c.ListControllers()
+ if err != nil {
+ return err
+ }
+ if err := c.ToggleControllers(controllers, v2.Enable); err != nil {
+ return err
+ }
+ }
+ return nil
+ },
+}
+
+var delCommand = cli.Command{
+ Name: "del",
+ Usage: "delete a cgroup",
+ Action: func(clix *cli.Context) error {
+ path := clix.Args().First()
+ c, err := v2.LoadManager(clix.GlobalString("mountpoint"), path)
+ if err != nil {
+ return err
+ }
+ return c.Delete()
+ },
+}
+
+var listCommand = cli.Command{
+ Name: "list",
+ Usage: "list processes in a cgroup",
+ Action: func(clix *cli.Context) error {
+ path := clix.Args().First()
+ c, err := v2.LoadManager(clix.GlobalString("mountpoint"), path)
+ if err != nil {
+ return err
+ }
+ procs, err := c.Procs(true)
+ if err != nil {
+ return err
+ }
+ for _, p := range procs {
+ fmt.Println(p)
+ }
+ return nil
+ },
+}
diff --git a/cmd/cgroups-playground/main.go b/cmd/cgroups-playground/main.go
deleted file mode 100644
index 641b541d..00000000
--- a/cmd/cgroups-playground/main.go
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- Copyright The containerd Authors.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
- http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-*/
-
-package main
-
-import (
- "os"
-
- v2 "github.com/containerd/cgroups/v2"
- "github.com/sirupsen/logrus"
-)
-
-func main() {
- if err := xmain(); err != nil {
- logrus.Fatalf("%+v", err)
- }
-}
-
-func xmain() error {
- pid := os.Getpid()
- g, err := v2.PidGroupPath(pid)
- if err != nil {
- return err
- }
- unifiedMountpoint := "/sys/fs/cgroup"
- logrus.Infof("Loading V2 for %q (PID %d), mountpoint=%q", g, pid, unifiedMountpoint)
- cg, err := v2.LoadManager(unifiedMountpoint, g)
- if err != nil {
- return err
- }
- processes, err := cg.Procs(true)
- if err != nil {
- return err
- }
- logrus.Infof("Has %d processes (recursively)", len(processes))
- for i, s := range processes {
- logrus.Infof("Process %d: %d", i, s)
- }
-
- return nil
-}
diff --git a/v2/errors.go b/v2/errors.go
index 60af72dd..46d2d9c2 100644
--- a/v2/errors.go
+++ b/v2/errors.go
@@ -31,8 +31,7 @@ var (
ErrCPUNotSupported = errors.New("cgroups: cpu cgroup (v2) not supported on this system")
ErrCgroupDeleted = errors.New("cgroups: cgroup deleted")
ErrNoCgroupMountDestination = errors.New("cgroups: cannot find cgroup mount destination")
-
- ErrInvalidGroupPath = errors.New("cgroups: group path format must be compatible with /proc/PID/cgroup")
+ ErrInvalidGroupPath = errors.New("cgroups: invalid group path")
)
// ErrorHandler is a function that handles and acts on errors
diff --git a/v2/manager.go b/v2/manager.go
index cc8397dc..5b6f2d62 100644
--- a/v2/manager.go
+++ b/v2/manager.go
@@ -17,6 +17,7 @@
package v2
import (
+ "bufio"
"io/ioutil"
"os"
"path/filepath"
@@ -27,6 +28,10 @@ import (
"github.com/pkg/errors"
)
+const (
+ subtreeControl = "cgroup.subtree_control"
+)
+
type cgValuer interface {
Values() []Value
}
@@ -93,18 +98,19 @@ func writeValues(path string, values []Value) error {
}
func NewManager(mountpoint string, group string, resources *Resources) (*Manager, error) {
- if err := VerifyGroupPath(group); err != nil {
- return nil, err
+ if group == "" {
+ return nil, ErrInvalidGroupPath
}
-
path := filepath.Join(mountpoint, group)
if err := os.MkdirAll(path, defaultDirPerm); err != nil {
return nil, err
}
- if err := writeValues(path, resources.Values()); err != nil {
- // clean up cgroup dir on failure
- os.Remove(path)
- return nil, err
+ if resources != nil {
+ if err := writeValues(path, resources.Values()); err != nil {
+ // clean up cgroup dir on failure
+ os.Remove(path)
+ return nil, err
+ }
}
return &Manager{
unifiedMountpoint: mountpoint,
@@ -113,8 +119,8 @@ func NewManager(mountpoint string, group string, resources *Resources) (*Manager
}
func LoadManager(mountpoint string, group string) (*Manager, error) {
- if err := VerifyGroupPath(group); err != nil {
- return nil, err
+ if group == "" {
+ return nil, ErrInvalidGroupPath
}
path := filepath.Join(mountpoint, group)
return &Manager{
@@ -128,6 +134,58 @@ type Manager struct {
path string
}
+func (c *Manager) ListControllers() ([]string, error) {
+ f, err := os.Open(filepath.Join(c.path, subtreeControl))
+ if err != nil {
+ return nil, err
+ }
+ defer f.Close()
+
+ var (
+ out []string
+ s = bufio.NewScanner(f)
+ )
+ s.Split(bufio.ScanWords)
+ for s.Scan() {
+ if err := s.Err(); err != nil {
+ return nil, err
+ }
+ out = append(out, s.Text())
+ }
+ return out, nil
+}
+
+type ControllerToggle int
+
+const (
+ Enable ControllerToggle = iota + 1
+ Disable
+)
+
+func toggleFunc(controllers []string, prefix string) []string {
+ out := make([]string, len(controllers))
+ for i, c := range controllers {
+ out[i] = prefix + c
+ }
+ return out
+}
+
+func (c *Manager) ToggleControllers(controllers []string, t ControllerToggle) error {
+ f, err := os.OpenFile(filepath.Join(c.path, subtreeControl), os.O_WRONLY, 0)
+ if err != nil {
+ return err
+ }
+ defer f.Close()
+ switch t {
+ case Enable:
+ controllers = toggleFunc(controllers, "+")
+ case Disable:
+ controllers = toggleFunc(controllers, "-")
+ }
+ _, err = f.WriteString(strings.Join(controllers, " "))
+ return err
+}
+
func (c *Manager) NewChild(name string, resources *Resources) (*Manager, error) {
if strings.HasPrefix(name, "/") {
return nil, errors.New("name must be relative")
diff --git a/v2/paths.go b/v2/paths.go
index 75d450f2..171e45bd 100644
--- a/v2/paths.go
+++ b/v2/paths.go
@@ -19,7 +19,6 @@ package v2
import (
"fmt"
"path/filepath"
- "strings"
)
// NestedGroupPath will nest the cgroups based on the calling processes cgroup
@@ -38,16 +37,3 @@ func PidGroupPath(pid int) (string, error) {
p := fmt.Sprintf("/proc/%d/cgroup", pid)
return parseCgroupFile(p)
}
-
-// VerifyGroupPath verifies the format of g.
-// VerifyGroupPath doesn't verify whether g actually exists on the system.
-func VerifyGroupPath(g string) error {
- s := string(g)
- if !strings.HasPrefix(s, "/") {
- return ErrInvalidGroupPath
- }
- if strings.HasPrefix(s, "/sys/fs/cgroup") {
- return ErrInvalidGroupPath
- }
- return nil
-}