Files
runc/libcontainer/container_linux_test.go
Kir Kolyshkin 201d60c51d runc run/start/exec: fix init log forwarding race
Sometimes debug.bats test cases are failing like this:

> not ok 27 global --debug to --log --log-format 'json'
> # (in test file tests/integration/debug.bats, line 77)
> #   `[[ "${output}" == *"child process in init()"* ]]' failed

It happens more when writing to disk.

This issue is caused by the fact that runc spawns log forwarding goroutine
(ForwardLogs) but does not wait for it to finish, resulting in missing
debug lines from nsexec.

ForwardLogs itself, though, never finishes, because it reads from a
reading side of a pipe which writing side is not closed. This is
especially true in case of runc create, which spawns runc init and
exits; meanwhile runc init waits on exec fifo for arbitrarily long
time before doing execve.

So, to fix the failure described above, we need to:

 1. Make runc create/run/exec wait for ForwardLogs to finish;

 2. Make runc init close its log pipe file descriptor (i.e.
    the one which value is passed in _LIBCONTAINER_LOGPIPE
    environment variable).

This is exactly what this commit does:

 1. Amend ForwardLogs to return a channel, and wait for it in start().

 2. In runc init, save the log fd and close it as late as possible.

PS I have to admit I still do not understand why an explicit close of
log pipe fd is required in e.g. (*linuxSetnsInit).Init, right before
the execve which (thanks to CLOEXEC) closes the fd anyway.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
2021-03-25 19:18:55 -07:00

404 lines
9.2 KiB
Go

// +build linux
package libcontainer
import (
"fmt"
"io/ioutil"
"os"
"testing"
"github.com/opencontainers/runc/libcontainer/cgroups"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/opencontainers/runc/libcontainer/intelrdt"
"github.com/opencontainers/runc/libcontainer/system"
)
type mockCgroupManager struct {
pids []int
allPids []int
stats *cgroups.Stats
paths map[string]string
}
type mockIntelRdtManager struct {
stats *intelrdt.Stats
path string
}
func (m *mockCgroupManager) GetPids() ([]int, error) {
return m.pids, nil
}
func (m *mockCgroupManager) GetAllPids() ([]int, error) {
return m.allPids, nil
}
func (m *mockCgroupManager) GetStats() (*cgroups.Stats, error) {
return m.stats, nil
}
func (m *mockCgroupManager) Apply(pid int) error {
return nil
}
func (m *mockCgroupManager) Set(container *configs.Config) error {
return nil
}
func (m *mockCgroupManager) Destroy() error {
return nil
}
func (m *mockCgroupManager) Exists() bool {
_, err := os.Lstat(m.Path("devices"))
return err == nil
}
func (m *mockCgroupManager) OOMKillCount() (uint64, error) {
return 0, nil
}
func (m *mockCgroupManager) GetPaths() map[string]string {
return m.paths
}
func (m *mockCgroupManager) Path(subsys string) string {
return m.paths[subsys]
}
func (m *mockCgroupManager) Freeze(state configs.FreezerState) error {
return nil
}
func (m *mockCgroupManager) GetCgroups() (*configs.Cgroup, error) {
return nil, nil
}
func (m *mockCgroupManager) GetFreezerState() (configs.FreezerState, error) {
return configs.Thawed, nil
}
func (m *mockIntelRdtManager) Apply(pid int) error {
return nil
}
func (m *mockIntelRdtManager) GetStats() (*intelrdt.Stats, error) {
return m.stats, nil
}
func (m *mockIntelRdtManager) Destroy() error {
return nil
}
func (m *mockIntelRdtManager) GetPath() string {
return m.path
}
func (m *mockIntelRdtManager) Set(container *configs.Config) error {
return nil
}
func (m *mockIntelRdtManager) GetCgroups() (*configs.Cgroup, error) {
return nil, nil
}
type mockProcess struct {
_pid int
started uint64
}
func (m *mockProcess) terminate() error {
return nil
}
func (m *mockProcess) pid() int {
return m._pid
}
func (m *mockProcess) startTime() (uint64, error) {
return m.started, nil
}
func (m *mockProcess) start() error {
return nil
}
func (m *mockProcess) wait() (*os.ProcessState, error) {
return nil, nil
}
func (m *mockProcess) signal(_ os.Signal) error {
return nil
}
func (m *mockProcess) externalDescriptors() []string {
return []string{}
}
func (m *mockProcess) setExternalDescriptors(newFds []string) {
}
func (m *mockProcess) forwardChildLogs() chan error {
return nil
}
func TestGetContainerPids(t *testing.T) {
pid := 1
stat, err := system.Stat(pid)
if err != nil {
t.Fatalf("can't stat pid %d, got %v", pid, err)
}
container := &linuxContainer{
id: "myid",
config: &configs.Config{},
cgroupManager: &mockCgroupManager{
allPids: []int{1, 2, 3},
paths: map[string]string{
"device": "/proc/self/cgroups",
},
},
initProcess: &mockProcess{
_pid: 1,
started: 10,
},
initProcessStartTime: stat.StartTime,
}
container.state = &runningState{c: container}
pids, err := container.Processes()
if err != nil {
t.Fatal(err)
}
for i, expected := range []int{1, 2, 3} {
if pids[i] != expected {
t.Fatalf("expected pid %d but received %d", expected, pids[i])
}
}
}
func TestGetContainerStats(t *testing.T) {
container := &linuxContainer{
id: "myid",
config: &configs.Config{},
cgroupManager: &mockCgroupManager{
pids: []int{1, 2, 3},
stats: &cgroups.Stats{
MemoryStats: cgroups.MemoryStats{
Usage: cgroups.MemoryData{
Usage: 1024,
},
},
},
},
intelRdtManager: &mockIntelRdtManager{
stats: &intelrdt.Stats{
L3CacheSchema: "L3:0=f;1=f0",
MemBwSchema: "MB:0=20;1=70",
},
},
}
stats, err := container.Stats()
if err != nil {
t.Fatal(err)
}
if stats.CgroupStats == nil {
t.Fatal("cgroup stats are nil")
}
if stats.CgroupStats.MemoryStats.Usage.Usage != 1024 {
t.Fatalf("expected memory usage 1024 but received %d", stats.CgroupStats.MemoryStats.Usage.Usage)
}
if intelrdt.IsCATEnabled() {
if stats.IntelRdtStats == nil {
t.Fatal("intel rdt stats are nil")
}
if stats.IntelRdtStats.L3CacheSchema != "L3:0=f;1=f0" {
t.Fatalf("expected L3CacheSchema L3:0=f;1=f0 but received %s", stats.IntelRdtStats.L3CacheSchema)
}
}
if intelrdt.IsMBAEnabled() {
if stats.IntelRdtStats == nil {
t.Fatal("intel rdt stats are nil")
}
if stats.IntelRdtStats.MemBwSchema != "MB:0=20;1=70" {
t.Fatalf("expected MemBwSchema MB:0=20;1=70 but received %s", stats.IntelRdtStats.MemBwSchema)
}
}
}
func TestGetContainerState(t *testing.T) {
var (
pid = os.Getpid()
expectedMemoryPath = "/sys/fs/cgroup/memory/myid"
expectedNetworkPath = fmt.Sprintf("/proc/%d/ns/net", pid)
expectedIntelRdtPath = "/sys/fs/resctrl/myid"
)
container := &linuxContainer{
id: "myid",
config: &configs.Config{
Namespaces: []configs.Namespace{
{Type: configs.NEWPID},
{Type: configs.NEWNS},
{Type: configs.NEWNET, Path: expectedNetworkPath},
{Type: configs.NEWUTS},
// emulate host for IPC
//{Type: configs.NEWIPC},
{Type: configs.NEWCGROUP},
},
},
initProcess: &mockProcess{
_pid: pid,
started: 10,
},
cgroupManager: &mockCgroupManager{
pids: []int{1, 2, 3},
stats: &cgroups.Stats{
MemoryStats: cgroups.MemoryStats{
Usage: cgroups.MemoryData{
Usage: 1024,
},
},
},
paths: map[string]string{
"memory": expectedMemoryPath,
},
},
intelRdtManager: &mockIntelRdtManager{
stats: &intelrdt.Stats{
L3CacheSchema: "L3:0=f0;1=f",
MemBwSchema: "MB:0=70;1=20",
},
path: expectedIntelRdtPath,
},
}
container.state = &createdState{c: container}
state, err := container.State()
if err != nil {
t.Fatal(err)
}
if state.InitProcessPid != pid {
t.Fatalf("expected pid %d but received %d", pid, state.InitProcessPid)
}
if state.InitProcessStartTime != 10 {
t.Fatalf("expected process start time 10 but received %d", state.InitProcessStartTime)
}
paths := state.CgroupPaths
if paths == nil {
t.Fatal("cgroup paths should not be nil")
}
if memPath := paths["memory"]; memPath != expectedMemoryPath {
t.Fatalf("expected memory path %q but received %q", expectedMemoryPath, memPath)
}
if intelrdt.IsCATEnabled() || intelrdt.IsMBAEnabled() {
intelRdtPath := state.IntelRdtPath
if intelRdtPath == "" {
t.Fatal("intel rdt path should not be empty")
}
if intelRdtPath != expectedIntelRdtPath {
t.Fatalf("expected intel rdt path %q but received %q", expectedIntelRdtPath, intelRdtPath)
}
}
for _, ns := range container.config.Namespaces {
path := state.NamespacePaths[ns.Type]
if path == "" {
t.Fatalf("expected non nil namespace path for %s", ns.Type)
}
if ns.Type == configs.NEWNET {
if path != expectedNetworkPath {
t.Fatalf("expected path %q but received %q", expectedNetworkPath, path)
}
} else {
file := ""
switch ns.Type {
case configs.NEWNET:
file = "net"
case configs.NEWNS:
file = "mnt"
case configs.NEWPID:
file = "pid"
case configs.NEWIPC:
file = "ipc"
case configs.NEWUSER:
file = "user"
case configs.NEWUTS:
file = "uts"
case configs.NEWCGROUP:
file = "cgroup"
}
expected := fmt.Sprintf("/proc/%d/ns/%s", pid, file)
if expected != path {
t.Fatalf("expected path %q but received %q", expected, path)
}
}
}
}
func TestGetContainerStateAfterUpdate(t *testing.T) {
var (
pid = os.Getpid()
)
stat, err := system.Stat(pid)
if err != nil {
t.Fatal(err)
}
rootDir, err := ioutil.TempDir("", "TestGetContainerStateAfterUpdate")
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(rootDir)
container := &linuxContainer{
root: rootDir,
id: "myid",
config: &configs.Config{
Namespaces: []configs.Namespace{
{Type: configs.NEWPID},
{Type: configs.NEWNS},
{Type: configs.NEWNET},
{Type: configs.NEWUTS},
{Type: configs.NEWIPC},
},
Cgroups: &configs.Cgroup{
Resources: &configs.Resources{
Memory: 1024,
},
},
},
initProcess: &mockProcess{
_pid: pid,
started: stat.StartTime,
},
cgroupManager: &mockCgroupManager{},
}
container.state = &createdState{c: container}
state, err := container.State()
if err != nil {
t.Fatal(err)
}
if state.InitProcessPid != pid {
t.Fatalf("expected pid %d but received %d", pid, state.InitProcessPid)
}
if state.InitProcessStartTime != stat.StartTime {
t.Fatalf("expected process start time %d but received %d", stat.StartTime, state.InitProcessStartTime)
}
if state.Config.Cgroups.Resources.Memory != 1024 {
t.Fatalf("expected Memory to be 1024 but received %q", state.Config.Cgroups.Memory)
}
// Set initProcessStartTime so we fake to be running
container.initProcessStartTime = state.InitProcessStartTime
container.state = &runningState{c: container}
newConfig := container.Config()
newConfig.Cgroups.Resources.Memory = 2048
if err := container.Set(newConfig); err != nil {
t.Fatal(err)
}
state, err = container.State()
if err != nil {
t.Fatal(err)
}
if state.Config.Cgroups.Resources.Memory != 2048 {
t.Fatalf("expected Memory to be 2048 but received %q", state.Config.Cgroups.Memory)
}
}