fix!: adjust auto cgroup root detection

Signed-off-by: black-desk <me@black-desk.cn>

go.mod

@@ -4,7 +4,6 @@ go 1.21
 
 require (
 	github.com/black-desk/lib/go v0.0.0-20231023094454-94c87a910679
-	github.com/deniswernert/go-fstab v0.0.0-20141204152952-eb4090f26517
 	github.com/go-playground/validator/v10 v10.16.0
 	github.com/google/nftables v0.1.1-0.20231024065723-32bfbb662717
 	github.com/onsi/ginkgo/v2 v2.13.2

go.sum

@@ -6,8 +6,6 @@ github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46t
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/deniswernert/go-fstab v0.0.0-20141204152952-eb4090f26517 h1:YMvaGdOIUowdD6ZybqLsUamGvWONZViUeW6T22U7fP0=
-github.com/deniswernert/go-fstab v0.0.0-20141204152952-eb4090f26517/go.mod h1:ixLGX4GUQg44igA/iJawr+KYZLyWOoAzAgTCQcJ/K9Y=
 github.com/gabriel-vasile/mimetype v1.4.3 h1:in2uUcidCuFcDKtdcBxlR0rJ1+fsokWf+uqxgUFjbI0=
 github.com/gabriel-vasile/mimetype v1.4.3/go.mod h1:d8uq/6HKRL6CGdk+aubisF/M5GcPfT7nKyLpA0lbSSk=
 github.com/go-logr/logr v1.3.0 h1:2y3SDp0ZXuc6/cjLSZ+Q3ir+QB9T/iG5yYRXqsagWSY=

pkg/cgtproxy/config/error.go

@@ -5,5 +5,5 @@ import (
 )
 
 var (
-	ErrCannotFoundCgroupv2Mount = errors.New("`cgroup2` mount point not found in /proc/mounts.")
+	ErrCannotFoundCgroupv2Root = errors.New("`cgroup2` mount point not found.")
 )

pkg/cgtproxy/config/private.go

@@ -2,9 +2,9 @@ package config
 
 import (
 	"fmt"
+	"os"
 
 	. "github.com/black-desk/lib/go/errwrap"
-	fstab "github.com/deniswernert/go-fstab"
 	"github.com/go-playground/validator/v10"
 )
 
@@ -58,36 +58,23 @@ func (c *Config) check() (err error) {
 func getCgroupRoot() (cgroupRoot CGroupRoot, err error) {
 	defer Wrap(&err, "get cgroupv2 mount point")
 
-	var mounts fstab.Mounts
-	mounts, err = fstab.ParseProc()
-	if err != nil {
-		return
-	}
+	paths := []string{"/sys/fs/cgroup/unified", "/sys/fs/cgroup"}
 
-	var (
-		mountFound bool
-		fsFile     CGroupRoot
-	)
-	for i := range mounts {
-		mount := mounts[i]
-		fsVfsType := mount.VfsType
-
-		if fsVfsType != "cgroup2" {
+	for i := range paths {
+		var fileInfo os.FileInfo
+		fileInfo, err = os.Stat(paths[i])
+		if err != nil {
 			continue
 		}
 
-		fsFile = CGroupRoot(mount.File)
-		mountFound = true
-
-		break
-	}
+		if !fileInfo.IsDir() {
+			continue
+		}
 
-	if !mountFound {
-		err = ErrCannotFoundCgroupv2Mount
+		cgroupRoot = CGroupRoot(paths[i])
 		return
 	}
 
-	cgroupRoot = fsFile
-
+	err = ErrCannotFoundCgroupv2Root
 	return
 }