fix: failed to get correct cgroup path in test

test/cli_run_cgroup_test.go

@@ -3,10 +3,12 @@ package main
 import (
 	"os"
 	"os/exec"
+	"path/filepath"
 	"strings"
 
 	"github.com/alibaba/pouch/test/command"
 	"github.com/alibaba/pouch/test/environment"
+	"github.com/alibaba/pouch/test/util"
 
 	"github.com/go-check/check"
 	"github.com/gotestyourself/gotestyourself/icmd"
@@ -51,18 +53,14 @@ func testRunWithCgroupParent(c *check.C, cgroupParent, name string) {
 	defer DelContainerForceMultyTime(c, name)
 	res.Assert(c, icmd.Success)
 
-	containerID, err := inspectFilter(name, ".ID")
-	c.Assert(err, check.IsNil)
-
-	// this code slice may not robust, but for this test case is enough.
-	cgroupParent = strings.TrimPrefix(cgroupParent, "/")
+	res = command.PouchRun("exec", name, "cat", "/proc/self/cgroup")
+	res.Assert(c, icmd.Success)
+	cgroupPaths := util.ParseCgroupFile(res.Stdout())
 
-	if cgroupParent == "" {
-		cgroupParent = "default"
-	}
+	cgroupMount, err := util.FindCgroupMountpoint("memory")
+	c.Assert(err, check.IsNil)
 
-	file := "/sys/fs/cgroup/memory/" + cgroupParent + "/" +
-		containerID + "/memory.limit_in_bytes"
+	file := filepath.Join(cgroupMount, cgroupPaths["memory"], "memory.limit_in_bytes")
 	if _, err := os.Stat(file); err != nil {
 		c.Fatalf("container %s cgroup mountpoint not exists", name)
 	}

test/util/util.go

@@ -1,7 +1,9 @@
 package util
 
 import (
+	"bufio"
 	"fmt"
+	"os"
 	"strings"
 	"time"
 
@@ -80,3 +82,48 @@ func StringSliceTrimSpace(input []string) ([]string, error) {
 
 	return output, nil
 }
+
+// ParseCgroupFile parse cgroup path from cgroup file
+func ParseCgroupFile(text string) map[string]string {
+	cgroups := make(map[string]string)
+	for _, t := range strings.Split(text, "\n") {
+		parts := strings.SplitN(t, ":", 3)
+		if len(parts) < 3 {
+			continue
+		}
+		for _, sub := range strings.Split(parts[1], ",") {
+			cgroups[sub] = parts[2]
+		}
+	}
+	return cgroups
+}
+
+// FindCgroupMountpoint find cgroup mountpoint for a specified subsystem
+func FindCgroupMountpoint(subsystem string) (string, error) {
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		txt := scanner.Text()
+		fields := strings.Fields(txt)
+		if len(fields) < 5 {
+			continue
+		}
+		if strings.Contains(txt, "cgroup") {
+			for _, opt := range strings.Split(fields[len(fields)-1], ",") {
+				if opt == subsystem {
+					return fields[4], nil
+				}
+			}
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+
+	return "", fmt.Errorf("failed to find %s cgroup mountpoint", subsystem)
+}