Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

fix(linux): isInContainer works for current docker versions #408

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

fix(linux): isInContainer works for current docker versions #408

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
62 changes: 60 additions & 2 deletions service_linux.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,13 +6,16 @@ package service

import (
"bufio"
"errors"
"fmt"
"io/ioutil"
"os"
"strings"
)

var cgroupFile = "/proc/1/cgroup"
var mountInfoFile = "/proc/self/mountinfo"
var dockerEnvFile = "/.dockerenv"

type linuxSystemService struct {
name string
Expand Down Expand Up @@ -98,7 +101,7 @@ func binaryName(pid int) (string, error) {
}

func isInteractive() (bool, error) {
inContainer, err := isInContainer(cgroupFile)
inContainer, err := isInContainer()
if err != nil {
return false, err
}
Expand All @@ -118,7 +121,62 @@ func isInteractive() (bool, error) {

// isInContainer checks if the service is being executed in docker or lxc
// container.
func isInContainer(cgroupPath string) (bool, error) {
func isInContainer() (bool, error) {
inContainer, err := isInContainerDockerEnv(dockerEnvFile)
if err != nil {
return false, err
}
if inContainer {
return true, nil
}

inContainer, err = isInContainerCGroup(cgroupFile)
if err != nil {
return false, err
}
if inContainer {
return true, nil
}

return isInContainerMountInfo(mountInfoFile)
}

func isInContainerDockerEnv(filePath string) (bool, error) {
_, err := os.Stat(filePath)
if err == nil {
return true, nil
}
if errors.Is(err, os.ErrNotExist) {
return false, nil
}

return false, err
}

func isInContainerMountInfo(filePath string) (bool, error) {
const maxlines = 15 // maximum lines to scan
f, err := os.Open(filePath)
if err != nil {
return false, err
}
defer f.Close()
scan := bufio.NewScanner(f)

lines := 0
for scan.Scan() && !(lines > maxlines) {
if strings.Contains(scan.Text(), "/docker/containers") {
return true, nil
}
lines++
}
if err := scan.Err(); err != nil {
return false, err
}

return false, nil
}

func isInContainerCGroup(cgroupPath string) (bool, error) {
const maxlines = 5 // maximum lines to scan

f, err := os.Open(cgroupPath)
Expand Down
129 changes: 126 additions & 3 deletions service_linux_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -36,13 +36,38 @@ func createTestCgroupFiles() (*os.File, *os.File, error) {
return hDockerGrp, hLinuxGrp, nil
}

// createTestMountInfoFiles creates mock files for tests
func createTestMountInfoFiles() (*os.File, *os.File, error) {
// docker cgroup setup
hDockerGrp, err := os.CreateTemp("", "*")
if err != nil {
return nil, nil, errors.New("docker tempfile create failed")
}
_, err = hDockerGrp.Write([]byte(dockerMountInfo))
if err != nil {
return nil, nil, errors.New("docker tempfile write failed")
}

// linux cgroup setup
hLinuxGrp, err := os.CreateTemp("", "*")
if err != nil {
return nil, nil, errors.New("\"normal\" tempfile create failed")
}
_, err = hLinuxGrp.Write([]byte(linuxMountInfo))
if err != nil {
return nil, nil, errors.New("\"normal\" tempfile write failed")
}

return hDockerGrp, hLinuxGrp, nil
}

// removeTestFile closes and removes the provided file
func removeTestFile(hFile *os.File) {
hFile.Close()
os.Remove(hFile.Name())
}

func Test_isInContainer(t *testing.T) {
func Test_isInContainerCGroup(t *testing.T) {

// setup
hDockerGrp, hLinuxGrp, err := createTestCgroupFiles()
Expand All @@ -57,7 +82,46 @@ func Test_isInContainer(t *testing.T) {

// TEST
type args struct {
cgroupPath string
filePath string
}
tests := []struct {
name string
args args
want bool
wantErr bool
}{
{"docker", args{hDockerGrp.Name()}, true, false},
{"linux", args{hLinuxGrp.Name()}, false, false},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got, err := isInContainerCGroup(tt.args.filePath)
if (err != nil) != tt.wantErr {
t.Errorf("isInContainer() error = %v, wantErr %v", err, tt.wantErr)
return
}
if got != tt.want {
t.Errorf("isInContainer() = %v, want %v", got, tt.want)
}
})
}
}
func Test_isInContainerMountInfo(t *testing.T) {

// setup
hDockerGrp, hLinuxGrp, err := createTestMountInfoFiles()
if err != nil {
t.Fatal(err)
}
defer func() {
// tear down
removeTestFile(hDockerGrp)
removeTestFile(hLinuxGrp)
}()

// TEST
type args struct {
filePath string
}
tests := []struct {
name string
Expand All @@ -70,7 +134,36 @@ func Test_isInContainer(t *testing.T) {
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got, err := isInContainer(tt.args.cgroupPath)
got, err := isInContainerMountInfo(tt.args.filePath)
if (err != nil) != tt.wantErr {
t.Errorf("isInContainer() error = %v, wantErr %v", err, tt.wantErr)
return
}
if got != tt.want {
t.Errorf("isInContainer() = %v, want %v", got, tt.want)
}
})
}
}

func Test_isInContainerDockerEnv(t *testing.T) {

// TEST
type args struct {
filePath string
}
tests := []struct {
name string
args args
want bool
wantErr bool
}{
{"docker", args{os.TempDir()}, true, false},
{"linux", args{"/non_existent_file"}, false, false},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got, err := isInContainerDockerEnv(tt.args.filePath)
if (err != nil) != tt.wantErr {
t.Errorf("isInContainer() error = %v, wantErr %v", err, tt.wantErr)
return
Expand Down Expand Up @@ -170,4 +263,34 @@ const (
2:cpu,cpuacct:/
1:name=systemd:/init.scope
0::/init.scope`

dockerMountInfo = `3860 3859 0:159 / /dev/pts rw,nosuid,noexec,relatime - devpts devpts rw,gid=5,mode=620,ptmxmode=666
3861 3857 0:160 / /sys ro,nosuid,nodev,noexec,relatime - sysfs sysfs ro
3862 3861 0:29 / /sys/fs/cgroup ro,nosuid,nodev,noexec,relatime - cgroup2 cgroup rw
3863 3859 0:156 / /dev/mqueue rw,nosuid,nodev,noexec,relatime - mqueue mqueue rw
3864 3859 0:161 / /dev/shm rw,nosuid,nodev,noexec,relatime - tmpfs shm rw,size=65536k,inode64
3865 3857 259:4 /var/lib/docker/volumes/345b0c4550daa5dbc7f4fa9fbd28717844e69e235f2aa014c7d24114320dd9a1/_data /opt/data rw,relatime master:1 - ext4 /dev/nvme0n1p4 rw
3866 3857 259:4 /var/lib/docker/containers/ea4d56df6742a4940bfa0b31a4481707511f2da7b7c0708ffe901b46f461eb89/resolv.conf /etc/resolv.conf rw,relatime - ext4 /dev/nvme0n1p4 rw
3867 3857 259:4 /var/lib/docker/containers/ea4d56df6742a4940bfa0b31a4481707511f2da7b7c0708ffe901b46f461eb89/hostname /etc/hostname rw,relatime - ext4 /dev/nvme0n1p4 rw
3868 3857 259:4 /var/lib/docker/containers/ea4d56df6742a4940bfa0b31a4481707511f2da7b7c0708ffe901b46f461eb89/hosts /etc/hosts rw,relatime - ext4 /dev/nvme0n1p4 rw
3776 3859 0:159 /0 /dev/console rw,nosuid,noexec,relatime - devpts devpts rw,gid=5,mode=620,ptmxmode=666
3777 3858 0:157 /bus /proc/bus ro,nosuid,nodev,noexec,relatime - proc proc rw
3778 3858 0:157 /fs /proc/fs ro,nosuid,nodev,noexec,relatime - proc proc rw`

linuxMountInfo = `183 28 0:44 / /run/credentials/systemd-tmpfiles-setup.service ro,nosuid,nodev,noexec,relatime,nosymfollow shared:103 - tmpfs tmpfs rw,size=1024k,nr_inodes=1024,mode=700,inode64,noswap
129 36 0:45 / /proc/sys/fs/binfmt_misc rw,nosuid,nodev,noexec,relatime shared:105 - binfmt_misc binfmt_misc rw
407 28 0:48 / /run/credentials/systemd-resolved.service ro,nosuid,nodev,noexec,relatime,nosymfollow shared:107 - tmpfs tmpfs rw,size=1024k,nr_inodes=1024,mode=700,inode64,noswap
166 30 0:60 / /var/lib/lxcfs rw,nosuid,nodev,relatime shared:329 - fuse.lxcfs lxcfs rw,user_id=0,group_id=0,allow_other
217 28 0:67 / /run/rpc_pipefs rw,relatime shared:911 - rpc_pipefs sunrpc rw
298 28 0:26 /snapd/ns /run/snapd/ns rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,size=4066576k,mode=755,inode64
335 298 0:4 mnt:[4026533124] /run/snapd/ns/cups.mnt rw - nsfs nsfs rw
1821 298 0:4 mnt:[4026533318] /run/snapd/ns/snapd-desktop-integration.mnt rw - nsfs nsfs rw
169 28 0:64 / /run/user/1000 rw,nosuid,nodev,relatime shared:700 - tmpfs tmpfs rw,size=4066576k,nr_inodes=1016644,mode=700,uid=1000,gid=1000,inode64
924 169 0:65 / /run/user/1000/doc rw,nosuid,nodev,relatime shared:794 - fuse.portal portal rw,user_id=1000,group_id=1000
2388 169 0:71 / /run/user/1000/gvfs rw,nosuid,nodev,relatime shared:814 - fuse.gvfsd-fuse gvfsd-fuse rw,user_id=1000,group_id=1000
2948 298 0:4 mnt:[4026534753] /run/snapd/ns/firmware-updater.mnt rw - nsfs nsfs rw
3517 30 0:129 / /var/lib/docker/overlay2/79490de289b65b7a63e86a6ae48a8607cf251030eec80d554f99eff740ba425e/merged rw,relatime shared:834 - overlay overlay rw,lowerdir=/var/lib/docker/overlay2/l/FCSCRZU3XZN6KVYV6UA4IU6CZM:/var/lib/docker/overlay2/l/I7GRZ2AVB7NO3MPA7VF75DF25N:/var/lib/docker/overlay2/l/3PHQOMHS6SD5HZFMUUENIQXENT:/var/lib/docker/overlay2/l/YOR22M55ADQZ4GRJIW3NR4EKF3:/var/lib/docker/overlay2/l/SLIJGALM6YROVNIV62WO7HLAXT,upperdir=/var/lib/docker/overlay2/79490de289b65b7a63e86a6ae48a8607cf251030eec80d554f99eff740ba425e/diff,workdir=/var/lib/docker/overlay2/79490de289b65b7a63e86a6ae48a8607cf251030eec80d554f99eff740ba425e/work,nouserxattr
3623 28 0:4 net:[4026537044] /run/docker/netns/e63556d83137 rw shared:1054 - nsfs nsfs rw
3548 30 0:137 / /var/lib/docker/overlay2/5f0fd269ad76199040b9b3ca1fa13ce36f9ab6799cd4b0b5406732c2c8407ff6/merged rw,relatime shared:1074 - overlay overlay rw,lowerdir=/var/lib/docker/overlay2/l/SXPONMLN4JW3QBFQWXCZ3RHVST:/var/lib/docker/overlay2/l/LA6JENXEZAPXZZF2FP4ON5WDEA:/var/lib/docker/overlay2/l/XEGVGERQJ7L72RWT3VIXEWGBL4:/var/lib/docker/overlay2/l/BPXXR3DHMVCSQWGSXG5NFNBE5W,upperdir=/var/lib/docker/overlay2/5f0fd269ad76199040b9b3ca1fa13ce36f9ab6799cd4b0b5406732c2c8407ff6/diff,workdir=/var/lib/docker/overlay2/5f0fd269ad76199040b9b3ca1fa13ce36f9ab6799cd4b0b5406732c2c8407ff6/work,nouserxattr
3700 28 0:4 net:[4026537144] /run/docker/netns/0b489b9c590d rw shared:1094 - nsfs nsfs rw`
)