Merge pull request #1443 from crosbymichael/daemon-cgroup

Place containerd inside cgroup

server/config.go

@@ -25,6 +25,8 @@ type Config struct {
 	Subreaper bool `toml:"subreaper"`
 	// OOMScore adjust the containerd's oom score
 	OOMScore int `toml:"oom_score"`
+	// Cgroup specifies cgroup information for the containerd daemon process
+	Cgroup CgroupConfig `toml:"cgroup"`
 
 	md toml.MetaData
 }
@@ -46,6 +48,10 @@ type MetricsConfig struct {
 	Address string `toml:"address"`
 }
 
+type CgroupConfig struct {
+	Path string `toml:"path"`
+}
+
 // Decode unmarshals a plugin specific configuration by plugin id
 func (c *Config) Decode(id string, v interface{}) (interface{}, error) {
 	data, ok := c.Plugins[id]

server/server_linux.go

@@ -4,8 +4,10 @@ import (
 	"context"
 	"os"
 
+	"github.com/containerd/cgroups"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/sys"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
 )
 
 const (
@@ -35,5 +37,21 @@ func apply(ctx context.Context, config *Config) error {
 			return err
 		}
 	}
+	if config.Cgroup.Path != "" {
+		cg, err := cgroups.Load(cgroups.V1, cgroups.StaticPath(config.Cgroup.Path))
+		if err != nil {
+			if err != cgroups.ErrCgroupDeleted {
+				return err
+			}
+			if cg, err = cgroups.New(cgroups.V1, cgroups.StaticPath(config.Cgroup.Path), &specs.LinuxResources{}); err != nil {
+				return err
+			}
+		}
+		if err := cg.Add(cgroups.Process{
+			Pid: os.Getpid(),
+		}); err != nil {
+			return err
+		}
+	}
 	return nil
 }