kubernetes/vendor/github.com/google/cadvisor/container/rkt/helpers.go
Davanum Srinivas 3fe776f24b
Update vendor dependencies
Change-Id: I3b1ca9f2687388c831d9d46a4e1de413ffae06ac
2018-11-10 07:50:31 -05:00

142 lines
3.9 KiB
Go

// Copyright 2016 Google Inc. All Rights Reserved.
//
// 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 rkt
import (
"fmt"
"io/ioutil"
"path"
"strings"
rktapi "github.com/coreos/rkt/api/v1alpha"
"golang.org/x/net/context"
"k8s.io/klog"
)
type parsedName struct {
Pod string
Container string
}
func verifyPod(name string) (bool, error) {
pod, err := cgroupToPod(name)
if err != nil || pod == nil {
return false, err
}
// Anything handler can handle is also accepted.
// Accept cgroups that are sub the pod cgroup, except "system.slice"
// - "system.slice" doesn't contain any processes itself
accept := !strings.HasSuffix(name, "/system.slice")
return accept, nil
}
func cgroupToPod(name string) (*rktapi.Pod, error) {
rktClient, err := Client()
if err != nil {
return nil, fmt.Errorf("couldn't get rkt api service: %v", err)
}
resp, err := rktClient.ListPods(context.Background(), &rktapi.ListPodsRequest{
Filters: []*rktapi.PodFilter{
{
States: []rktapi.PodState{rktapi.PodState_POD_STATE_RUNNING},
PodSubCgroups: []string{name},
},
},
})
if err != nil {
return nil, fmt.Errorf("failed to list pods: %v", err)
}
if len(resp.Pods) == 0 {
return nil, nil
}
if len(resp.Pods) != 1 {
return nil, fmt.Errorf("returned %d (expected 1) pods for cgroup %v", len(resp.Pods), name)
}
return resp.Pods[0], nil
}
/* Parse cgroup name into a pod/container name struct
Example cgroup fs name
pod - /machine.slice/machine-rkt\\x2df556b64a\\x2d17a7\\x2d47d7\\x2d93ec\\x2def2275c3d67e.scope/
or /system.slice/k8s-..../
container under pod - /machine.slice/machine-rkt\\x2df556b64a\\x2d17a7\\x2d47d7\\x2d93ec\\x2def2275c3d67e.scope/system.slice/alpine-sh.service
or /system.slice/k8s-..../system.slice/pause.service
*/
func parseName(name string) (*parsedName, error) {
pod, err := cgroupToPod(name)
if err != nil {
return nil, fmt.Errorf("parseName: couldn't convert %v to a rkt pod: %v", name, err)
}
if pod == nil {
return nil, fmt.Errorf("parseName: didn't return a pod for %v", name)
}
splits := strings.Split(name, "/")
parsed := &parsedName{}
if len(splits) == 3 || len(splits) == 5 {
parsed.Pod = pod.Id
if len(splits) == 5 {
parsed.Container = strings.Replace(splits[4], ".service", "", -1)
}
return parsed, nil
}
return nil, fmt.Errorf("%s not handled by rkt handler", name)
}
// Gets a Rkt container's overlay upper dir
func getRootFs(root string, parsed *parsedName) string {
/* Example of where it stores the upper dir key
for container
/var/lib/rkt/pods/run/bc793ec6-c48f-4480-99b5-6bec16d52210/appsinfo/alpine-sh/treeStoreID
for pod
/var/lib/rkt/pods/run/f556b64a-17a7-47d7-93ec-ef2275c3d67e/stage1TreeStoreID
*/
var tree string
if parsed.Container == "" {
tree = path.Join(root, "pods/run", parsed.Pod, "stage1TreeStoreID")
} else {
tree = path.Join(root, "pods/run", parsed.Pod, "appsinfo", parsed.Container, "treeStoreID")
}
bytes, err := ioutil.ReadFile(tree)
if err != nil {
klog.Errorf("ReadFile failed, couldn't read %v to get upper dir: %v", tree, err)
return ""
}
s := string(bytes)
/* Example of where the upper dir is stored via key read above
/var/lib/rkt/pods/run/bc793ec6-c48f-4480-99b5-6bec16d52210/overlay/deps-sha512-82a099e560a596662b15dec835e9adabab539cad1f41776a30195a01a8f2f22b/
*/
return path.Join(root, "pods/run", parsed.Pod, "overlay", s)
}