open-nomad/drivers/rawexec/driver_test.go
Seth Hoenig 2e5c6de820 client: enable support for cgroups v2
This PR introduces support for using Nomad on systems with cgroups v2 [1]
enabled as the cgroups controller mounted on /sys/fs/cgroups. Newer Linux
distros like Ubuntu 21.10 are shipping with cgroups v2 only, causing problems
for Nomad users.

Nomad mostly "just works" with cgroups v2 due to the indirection via libcontainer,
but not so for managing cpuset cgroups. Before, Nomad has been making use of
a feature in v1 where a PID could be a member of more than one cgroup. In v2
this is no longer possible, and so the logic around computing cpuset values
must be modified. When Nomad detects v2, it manages cpuset values in-process,
rather than making use of cgroup heirarchy inheritence via shared/reserved
parents.

Nomad will only activate the v2 logic when it detects cgroups2 is mounted at
/sys/fs/cgroups. This means on systems running in hybrid mode with cgroups2
mounted at /sys/fs/cgroups/unified (as is typical) Nomad will continue to
use the v1 logic, and should operate as before. Systems that do not support
cgroups v2 are also not affected.

When v2 is activated, Nomad will create a parent called nomad.slice (unless
otherwise configured in Client conifg), and create cgroups for tasks using
naming convention <allocID>-<task>.scope. These follow the naming convention
set by systemd and also used by Docker when cgroups v2 is detected.

Client nodes now export a new fingerprint attribute, unique.cgroups.version
which will be set to 'v1' or 'v2' to indicate the cgroups regime in use by
Nomad.

The new cpuset management strategy fixes #11705, where docker tasks that
spawned processes on startup would "leak". In cgroups v2, the PIDs are
started in the cgroup they will always live in, and thus the cause of
the leak is eliminated.

[1] https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html

Closes #11289
Fixes #11705 #11773 #11933
2022-03-23 11:35:27 -05:00

514 lines
13 KiB
Go

package rawexec
import (
"context"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"runtime"
"strconv"
"sync"
"syscall"
"testing"
"time"
"github.com/hashicorp/nomad/ci"
ctestutil "github.com/hashicorp/nomad/client/testutil"
"github.com/hashicorp/nomad/helper/pluginutils/hclutils"
"github.com/hashicorp/nomad/helper/testlog"
"github.com/hashicorp/nomad/helper/testtask"
"github.com/hashicorp/nomad/helper/uuid"
basePlug "github.com/hashicorp/nomad/plugins/base"
"github.com/hashicorp/nomad/plugins/drivers"
dtestutil "github.com/hashicorp/nomad/plugins/drivers/testutils"
pstructs "github.com/hashicorp/nomad/plugins/shared/structs"
"github.com/hashicorp/nomad/testutil"
"github.com/stretchr/testify/require"
)
func TestMain(m *testing.M) {
if !testtask.Run() {
os.Exit(m.Run())
}
}
func newEnabledRawExecDriver(t *testing.T) *Driver {
ctx, cancel := context.WithCancel(context.Background())
t.Cleanup(func() { cancel() })
d := NewRawExecDriver(ctx, testlog.HCLogger(t)).(*Driver)
d.config.Enabled = true
return d
}
func TestRawExecDriver_SetConfig(t *testing.T) {
ci.Parallel(t)
require := require.New(t)
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
d := NewRawExecDriver(ctx, testlog.HCLogger(t))
harness := dtestutil.NewDriverHarness(t, d)
defer harness.Kill()
bconfig := &basePlug.Config{}
// Disable raw exec.
config := &Config{}
var data []byte
require.NoError(basePlug.MsgPackEncode(&data, config))
bconfig.PluginConfig = data
require.NoError(harness.SetConfig(bconfig))
require.Exactly(config, d.(*Driver).config)
config.Enabled = true
config.NoCgroups = true
data = []byte{}
require.NoError(basePlug.MsgPackEncode(&data, config))
bconfig.PluginConfig = data
require.NoError(harness.SetConfig(bconfig))
require.Exactly(config, d.(*Driver).config)
config.NoCgroups = false
data = []byte{}
require.NoError(basePlug.MsgPackEncode(&data, config))
bconfig.PluginConfig = data
require.NoError(harness.SetConfig(bconfig))
require.Exactly(config, d.(*Driver).config)
}
func TestRawExecDriver_Fingerprint(t *testing.T) {
ci.Parallel(t)
fingerprintTest := func(config *Config, expected *drivers.Fingerprint) func(t *testing.T) {
return func(t *testing.T) {
require := require.New(t)
d := newEnabledRawExecDriver(t)
harness := dtestutil.NewDriverHarness(t, d)
defer harness.Kill()
var data []byte
require.NoError(basePlug.MsgPackEncode(&data, config))
bconfig := &basePlug.Config{
PluginConfig: data,
}
require.NoError(harness.SetConfig(bconfig))
fingerCh, err := harness.Fingerprint(context.Background())
require.NoError(err)
select {
case result := <-fingerCh:
require.Equal(expected, result)
case <-time.After(time.Duration(testutil.TestMultiplier()) * time.Second):
require.Fail("timeout receiving fingerprint")
}
}
}
cases := []struct {
Name string
Conf Config
Expected drivers.Fingerprint
}{
{
Name: "Disabled",
Conf: Config{
Enabled: false,
},
Expected: drivers.Fingerprint{
Attributes: nil,
Health: drivers.HealthStateUndetected,
HealthDescription: "disabled",
},
},
{
Name: "Enabled",
Conf: Config{
Enabled: true,
},
Expected: drivers.Fingerprint{
Attributes: map[string]*pstructs.Attribute{"driver.raw_exec": pstructs.NewBoolAttribute(true)},
Health: drivers.HealthStateHealthy,
HealthDescription: drivers.DriverHealthy,
},
},
}
for _, tc := range cases {
t.Run(tc.Name, fingerprintTest(&tc.Conf, &tc.Expected))
}
}
func TestRawExecDriver_StartWait(t *testing.T) {
ci.Parallel(t)
require := require.New(t)
d := newEnabledRawExecDriver(t)
harness := dtestutil.NewDriverHarness(t, d)
defer harness.Kill()
task := &drivers.TaskConfig{
ID: uuid.Generate(),
Name: "test",
}
tc := &TaskConfig{
Command: testtask.Path(),
Args: []string{"sleep", "10ms"},
}
require.NoError(task.EncodeConcreteDriverConfig(&tc))
testtask.SetTaskConfigEnv(task)
cleanup := harness.MkAllocDir(task, false)
defer cleanup()
handle, _, err := harness.StartTask(task)
require.NoError(err)
ch, err := harness.WaitTask(context.Background(), handle.Config.ID)
require.NoError(err)
var result *drivers.ExitResult
select {
case result = <-ch:
case <-time.After(5 * time.Second):
t.Fatal("timed out")
}
require.Zero(result.ExitCode)
require.Zero(result.Signal)
require.False(result.OOMKilled)
require.NoError(result.Err)
require.NoError(harness.DestroyTask(task.ID, true))
}
func TestRawExecDriver_StartWaitRecoverWaitStop(t *testing.T) {
ci.Parallel(t)
require := require.New(t)
d := newEnabledRawExecDriver(t)
harness := dtestutil.NewDriverHarness(t, d)
defer harness.Kill()
// Disable cgroups so test works without root
config := &Config{NoCgroups: true, Enabled: true}
var data []byte
require.NoError(basePlug.MsgPackEncode(&data, config))
bconfig := &basePlug.Config{PluginConfig: data}
require.NoError(harness.SetConfig(bconfig))
task := &drivers.TaskConfig{
ID: uuid.Generate(),
Name: "sleep",
}
tc := &TaskConfig{
Command: testtask.Path(),
Args: []string{"sleep", "100s"},
}
require.NoError(task.EncodeConcreteDriverConfig(&tc))
testtask.SetTaskConfigEnv(task)
cleanup := harness.MkAllocDir(task, false)
defer cleanup()
handle, _, err := harness.StartTask(task)
require.NoError(err)
ch, err := harness.WaitTask(context.Background(), task.ID)
require.NoError(err)
var waitDone bool
var wg sync.WaitGroup
wg.Add(1)
go func() {
defer wg.Done()
result := <-ch
require.Error(result.Err)
waitDone = true
}()
originalStatus, err := d.InspectTask(task.ID)
require.NoError(err)
d.tasks.Delete(task.ID)
wg.Wait()
require.True(waitDone)
_, err = d.InspectTask(task.ID)
require.Equal(drivers.ErrTaskNotFound, err)
err = d.RecoverTask(handle)
require.NoError(err)
status, err := d.InspectTask(task.ID)
require.NoError(err)
require.Exactly(originalStatus, status)
ch, err = harness.WaitTask(context.Background(), task.ID)
require.NoError(err)
wg.Add(1)
waitDone = false
go func() {
defer wg.Done()
result := <-ch
require.NoError(result.Err)
require.NotZero(result.ExitCode)
require.Equal(9, result.Signal)
waitDone = true
}()
time.Sleep(300 * time.Millisecond)
require.NoError(d.StopTask(task.ID, 0, "SIGKILL"))
wg.Wait()
require.NoError(d.DestroyTask(task.ID, false))
require.True(waitDone)
}
func TestRawExecDriver_Start_Wait_AllocDir(t *testing.T) {
ci.Parallel(t)
require := require.New(t)
d := newEnabledRawExecDriver(t)
harness := dtestutil.NewDriverHarness(t, d)
defer harness.Kill()
task := &drivers.TaskConfig{
ID: uuid.Generate(),
Name: "sleep",
}
cleanup := harness.MkAllocDir(task, false)
defer cleanup()
exp := []byte("win")
file := "output.txt"
outPath := fmt.Sprintf(`%s/%s`, task.TaskDir().SharedAllocDir, file)
tc := &TaskConfig{
Command: testtask.Path(),
Args: []string{"sleep", "1s", "write", string(exp), outPath},
}
require.NoError(task.EncodeConcreteDriverConfig(&tc))
testtask.SetTaskConfigEnv(task)
_, _, err := harness.StartTask(task)
require.NoError(err)
// Task should terminate quickly
waitCh, err := harness.WaitTask(context.Background(), task.ID)
require.NoError(err)
select {
case res := <-waitCh:
require.NoError(res.Err)
require.True(res.Successful())
case <-time.After(time.Duration(testutil.TestMultiplier()*5) * time.Second):
require.Fail("WaitTask timeout")
}
// Check that data was written to the shared alloc directory.
outputFile := filepath.Join(task.TaskDir().SharedAllocDir, file)
act, err := ioutil.ReadFile(outputFile)
require.NoError(err)
require.Exactly(exp, act)
require.NoError(harness.DestroyTask(task.ID, true))
}
// This test creates a process tree such that without cgroups tracking the
// processes cleanup of the children would not be possible. Thus the test
// asserts that the processes get killed properly when using cgroups.
func TestRawExecDriver_Start_Kill_Wait_Cgroup(t *testing.T) {
ci.Parallel(t)
ctestutil.ExecCompatible(t)
ctestutil.CgroupsCompatibleV1(t) // todo(shoenig) #12348
require := require.New(t)
pidFile := "pid"
d := newEnabledRawExecDriver(t)
harness := dtestutil.NewDriverHarness(t, d)
defer harness.Kill()
task := &drivers.TaskConfig{
ID: uuid.Generate(),
Name: "sleep",
User: "root",
}
cleanup := harness.MkAllocDir(task, false)
defer cleanup()
tc := &TaskConfig{
Command: testtask.Path(),
Args: []string{"fork/exec", pidFile, "pgrp", "0", "sleep", "20s"},
}
require.NoError(task.EncodeConcreteDriverConfig(&tc))
testtask.SetTaskConfigEnv(task)
_, _, err := harness.StartTask(task)
require.NoError(err)
// Find the process
var pidData []byte
testutil.WaitForResult(func() (bool, error) {
var err error
pidData, err = ioutil.ReadFile(filepath.Join(task.TaskDir().Dir, pidFile))
if err != nil {
return false, err
}
if len(pidData) == 0 {
return false, fmt.Errorf("pidFile empty")
}
return true, nil
}, func(err error) {
require.NoError(err)
})
pid, err := strconv.Atoi(string(pidData))
require.NoError(err, "failed to read pidData: %s", string(pidData))
// Check the pid is up
process, err := os.FindProcess(pid)
require.NoError(err)
require.NoError(process.Signal(syscall.Signal(0)))
var wg sync.WaitGroup
wg.Add(1)
go func() {
defer wg.Done()
time.Sleep(1 * time.Second)
err := harness.StopTask(task.ID, 0, "")
// Can't rely on the ordering between wait and kill on CI/travis...
if !testutil.IsCI() {
require.NoError(err)
}
}()
// Task should terminate quickly
waitCh, err := harness.WaitTask(context.Background(), task.ID)
require.NoError(err)
select {
case res := <-waitCh:
require.False(res.Successful())
case <-time.After(time.Duration(testutil.TestMultiplier()*5) * time.Second):
require.Fail("WaitTask timeout")
}
testutil.WaitForResult(func() (bool, error) {
if err := process.Signal(syscall.Signal(0)); err == nil {
return false, fmt.Errorf("process should not exist: %v", pid)
}
return true, nil
}, func(err error) {
require.NoError(err)
})
wg.Wait()
require.NoError(harness.DestroyTask(task.ID, true))
}
func TestRawExecDriver_Exec(t *testing.T) {
ci.Parallel(t)
ctestutil.ExecCompatible(t)
ctestutil.CgroupsCompatibleV1(t) // todo(shoenig) #12348
require := require.New(t)
d := newEnabledRawExecDriver(t)
harness := dtestutil.NewDriverHarness(t, d)
defer harness.Kill()
task := &drivers.TaskConfig{
ID: uuid.Generate(),
Name: "sleep",
}
cleanup := harness.MkAllocDir(task, false)
defer cleanup()
tc := &TaskConfig{
Command: testtask.Path(),
Args: []string{"sleep", "9000s"},
}
require.NoError(task.EncodeConcreteDriverConfig(&tc))
testtask.SetTaskConfigEnv(task)
_, _, err := harness.StartTask(task)
require.NoError(err)
if runtime.GOOS == "windows" {
// Exec a command that should work
res, err := harness.ExecTask(task.ID, []string{"cmd.exe", "/c", "echo", "hello"}, 1*time.Second)
require.NoError(err)
require.True(res.ExitResult.Successful())
require.Equal(string(res.Stdout), "hello\r\n")
// Exec a command that should fail
res, err = harness.ExecTask(task.ID, []string{"cmd.exe", "/c", "stat", "notarealfile123abc"}, 1*time.Second)
require.NoError(err)
require.False(res.ExitResult.Successful())
require.Contains(string(res.Stdout), "not recognized")
} else {
// Exec a command that should work
res, err := harness.ExecTask(task.ID, []string{"/usr/bin/stat", "/tmp"}, 1*time.Second)
require.NoError(err)
require.True(res.ExitResult.Successful())
require.True(len(res.Stdout) > 100)
// Exec a command that should fail
res, err = harness.ExecTask(task.ID, []string{"/usr/bin/stat", "notarealfile123abc"}, 1*time.Second)
require.NoError(err)
require.False(res.ExitResult.Successful())
require.Contains(string(res.Stdout), "No such file or directory")
}
require.NoError(harness.DestroyTask(task.ID, true))
}
func TestConfig_ParseAllHCL(t *testing.T) {
ci.Parallel(t)
cfgStr := `
config {
command = "/bin/bash"
args = ["-c", "echo hello"]
}`
expected := &TaskConfig{
Command: "/bin/bash",
Args: []string{"-c", "echo hello"},
}
var tc *TaskConfig
hclutils.NewConfigParser(taskConfigSpec).ParseHCL(t, cfgStr, &tc)
require.EqualValues(t, expected, tc)
}
func TestRawExecDriver_Disabled(t *testing.T) {
ci.Parallel(t)
require := require.New(t)
d := newEnabledRawExecDriver(t)
d.config.Enabled = false
harness := dtestutil.NewDriverHarness(t, d)
defer harness.Kill()
task := &drivers.TaskConfig{
ID: uuid.Generate(),
Name: "test",
}
handle, _, err := harness.StartTask(task)
require.Error(err)
require.Contains(err.Error(), errDisabledDriver.Error())
require.Nil(handle)
}