Files
nomad/plugins/drivers/testutils/testing.go
Michael Schurter 37f053ff89 client: never embed alloc_dir in chroot
Fixes #2522

Skip embedding client.alloc_dir when building chroot. If a user
configures a Nomad client agent so that the chroot_env will embed the
client.alloc_dir, Nomad will happily infinitely recurse while building
the chroot until something horrible happens. The best case scenario is
the filesystem's path length limit is hit. The worst case scenario is
disk space is exhausted.

A bad agent configuration will look something like this:

```hcl
data_dir = "/tmp/nomad-badagent"

client {
  enabled = true

  chroot_env {
    # Note that the source matches the data_dir
    "/tmp/nomad-badagent" = "/ohno"
    # ...
  }
}
```

Note that `/ohno/client` (the state_dir) will still be created but not
`/ohno/alloc` (the alloc_dir).
While I cannot think of a good reason why someone would want to embed
Nomad's client (and possibly server) directories in chroots, there
should be no cause for harm. chroots are only built when Nomad runs as
root, and Nomad disables running exec jobs as root by default. Therefore
even if client state is copied into chroots, it will be inaccessible to
tasks.

Skipping the `data_dir` and `{client,server}.state_dir` is possible, but
this PR attempts to implement the minimum viable solution to reduce risk
of unintended side effects or bugs.

When running tests as root in a vm without the fix, the following error
occurs:

```
=== RUN   TestAllocDir_SkipAllocDir
    alloc_dir_test.go:520:
                Error Trace:    alloc_dir_test.go:520
                Error:          Received unexpected error:
                                Couldn't create destination file /tmp/TestAllocDir_SkipAllocDir1457747331/001/nomad/test/testtask/nomad/test/testtask/.../nomad/test/testtask/secrets/.nomad-mount: open /tmp/TestAllocDir_SkipAllocDir1457747331/001/nomad/test/.../testtask/secrets/.nomad-mount: file name too long
                Test:           TestAllocDir_SkipAllocDir
--- FAIL: TestAllocDir_SkipAllocDir (22.76s)
```

Also removed unused Copy methods on AllocDir and TaskDir structs.

Thanks to @eveld for not letting me forget about this!
2021-10-18 09:22:01 -07:00

283 lines
9.3 KiB
Go

package testutils
import (
"context"
"fmt"
"io/ioutil"
"path/filepath"
"runtime"
"strings"
"time"
testing "github.com/mitchellh/go-testing-interface"
hclog "github.com/hashicorp/go-hclog"
plugin "github.com/hashicorp/go-plugin"
"github.com/hashicorp/nomad/client/allocdir"
"github.com/hashicorp/nomad/client/config"
"github.com/hashicorp/nomad/client/logmon"
"github.com/hashicorp/nomad/client/taskenv"
"github.com/hashicorp/nomad/helper/testlog"
"github.com/hashicorp/nomad/helper/uuid"
"github.com/hashicorp/nomad/nomad/mock"
"github.com/hashicorp/nomad/nomad/structs"
"github.com/hashicorp/nomad/plugins/base"
"github.com/hashicorp/nomad/plugins/drivers"
"github.com/hashicorp/nomad/plugins/shared/hclspec"
"github.com/stretchr/testify/require"
)
type DriverHarness struct {
drivers.DriverPlugin
client *plugin.GRPCClient
server *plugin.GRPCServer
t testing.T
logger hclog.Logger
impl drivers.DriverPlugin
}
func (d *DriverHarness) Impl() drivers.DriverPlugin {
return d.impl
}
func NewDriverHarness(t testing.T, d drivers.DriverPlugin) *DriverHarness {
logger := testlog.HCLogger(t).Named("driver_harness")
pd := drivers.NewDriverPlugin(d, logger)
client, server := plugin.TestPluginGRPCConn(t,
map[string]plugin.Plugin{
base.PluginTypeDriver: pd,
base.PluginTypeBase: &base.PluginBase{Impl: d},
"logmon": logmon.NewPlugin(logmon.NewLogMon(logger.Named("logmon"))),
},
)
raw, err := client.Dispense(base.PluginTypeDriver)
if err != nil {
t.Fatalf("err dispensing plugin: %v", err)
}
dClient := raw.(drivers.DriverPlugin)
h := &DriverHarness{
client: client,
server: server,
DriverPlugin: dClient,
logger: logger,
t: t,
impl: d,
}
return h
}
func (h *DriverHarness) Kill() {
h.client.Close()
h.server.Stop()
}
// MkAllocDir creates a temporary directory and allocdir structure.
// If enableLogs is set to true a logmon instance will be started to write logs
// to the LogDir of the task
// A cleanup func is returned and should be deferred so as to not leak dirs
// between tests.
func (h *DriverHarness) MkAllocDir(t *drivers.TaskConfig, enableLogs bool) func() {
dir, err := ioutil.TempDir("", "nomad_driver_harness-")
require.NoError(h.t, err)
t.AllocDir = dir
allocDir := allocdir.NewAllocDir(h.logger, dir, t.AllocID)
require.NoError(h.t, allocDir.Build())
taskDir := allocDir.NewTaskDir(t.Name)
caps, err := h.Capabilities()
require.NoError(h.t, err)
fsi := caps.FSIsolation
require.NoError(h.t, taskDir.Build(fsi == drivers.FSIsolationChroot, config.DefaultChrootEnv))
task := &structs.Task{
Name: t.Name,
Env: t.Env,
}
// Create the mock allocation
alloc := mock.Alloc()
if t.Resources != nil {
alloc.AllocatedResources.Tasks[task.Name] = t.Resources.NomadResources
}
taskBuilder := taskenv.NewBuilder(mock.Node(), alloc, task, "global")
SetEnvvars(taskBuilder, fsi, taskDir, config.DefaultConfig())
taskEnv := taskBuilder.Build()
if t.Env == nil {
t.Env = taskEnv.Map()
} else {
for k, v := range taskEnv.Map() {
if _, ok := t.Env[k]; !ok {
t.Env[k] = v
}
}
}
//logmon
if enableLogs {
lm := logmon.NewLogMon(h.logger.Named("logmon"))
if runtime.GOOS == "windows" {
id := uuid.Generate()[:8]
t.StdoutPath = fmt.Sprintf("//./pipe/%s-%s.stdout", t.Name, id)
t.StderrPath = fmt.Sprintf("//./pipe/%s-%s.stderr", t.Name, id)
} else {
t.StdoutPath = filepath.Join(taskDir.LogDir, fmt.Sprintf(".%s.stdout.fifo", t.Name))
t.StderrPath = filepath.Join(taskDir.LogDir, fmt.Sprintf(".%s.stderr.fifo", t.Name))
}
err = lm.Start(&logmon.LogConfig{
LogDir: taskDir.LogDir,
StdoutLogFile: fmt.Sprintf("%s.stdout", t.Name),
StderrLogFile: fmt.Sprintf("%s.stderr", t.Name),
StdoutFifo: t.StdoutPath,
StderrFifo: t.StderrPath,
MaxFiles: 10,
MaxFileSizeMB: 10,
})
require.NoError(h.t, err)
return func() {
lm.Stop()
h.client.Close()
allocDir.Destroy()
}
}
return func() {
h.client.Close()
allocDir.Destroy()
}
}
// WaitUntilStarted will block until the task for the given ID is in the running
// state or the timeout is reached
func (h *DriverHarness) WaitUntilStarted(taskID string, timeout time.Duration) error {
deadline := time.Now().Add(timeout)
var lastState drivers.TaskState
for {
status, err := h.InspectTask(taskID)
if err != nil {
return err
}
if status.State == drivers.TaskStateRunning {
return nil
}
lastState = status.State
if time.Now().After(deadline) {
return fmt.Errorf("task never transitioned to running, currently '%s'", lastState)
}
time.Sleep(100 * time.Millisecond)
}
}
// MockDriver is used for testing.
// Each function can be set as a closure to make assertions about how data
// is passed through the base plugin layer.
type MockDriver struct {
base.MockPlugin
TaskConfigSchemaF func() (*hclspec.Spec, error)
FingerprintF func(context.Context) (<-chan *drivers.Fingerprint, error)
CapabilitiesF func() (*drivers.Capabilities, error)
RecoverTaskF func(*drivers.TaskHandle) error
StartTaskF func(*drivers.TaskConfig) (*drivers.TaskHandle, *drivers.DriverNetwork, error)
WaitTaskF func(context.Context, string) (<-chan *drivers.ExitResult, error)
StopTaskF func(string, time.Duration, string) error
DestroyTaskF func(string, bool) error
InspectTaskF func(string) (*drivers.TaskStatus, error)
TaskStatsF func(context.Context, string, time.Duration) (<-chan *drivers.TaskResourceUsage, error)
TaskEventsF func(context.Context) (<-chan *drivers.TaskEvent, error)
SignalTaskF func(string, string) error
ExecTaskF func(string, []string, time.Duration) (*drivers.ExecTaskResult, error)
ExecTaskStreamingF func(context.Context, string, *drivers.ExecOptions) (*drivers.ExitResult, error)
MockNetworkManager
}
type MockNetworkManager struct {
CreateNetworkF func(string, *drivers.NetworkCreateRequest) (*drivers.NetworkIsolationSpec, bool, error)
DestroyNetworkF func(string, *drivers.NetworkIsolationSpec) error
}
func (m *MockNetworkManager) CreateNetwork(allocID string, req *drivers.NetworkCreateRequest) (*drivers.NetworkIsolationSpec, bool, error) {
return m.CreateNetworkF(allocID, req)
}
func (m *MockNetworkManager) DestroyNetwork(id string, spec *drivers.NetworkIsolationSpec) error {
return m.DestroyNetworkF(id, spec)
}
func (d *MockDriver) TaskConfigSchema() (*hclspec.Spec, error) { return d.TaskConfigSchemaF() }
func (d *MockDriver) Fingerprint(ctx context.Context) (<-chan *drivers.Fingerprint, error) {
return d.FingerprintF(ctx)
}
func (d *MockDriver) Capabilities() (*drivers.Capabilities, error) { return d.CapabilitiesF() }
func (d *MockDriver) RecoverTask(h *drivers.TaskHandle) error { return d.RecoverTaskF(h) }
func (d *MockDriver) StartTask(c *drivers.TaskConfig) (*drivers.TaskHandle, *drivers.DriverNetwork, error) {
return d.StartTaskF(c)
}
func (d *MockDriver) WaitTask(ctx context.Context, id string) (<-chan *drivers.ExitResult, error) {
return d.WaitTaskF(ctx, id)
}
func (d *MockDriver) StopTask(taskID string, timeout time.Duration, signal string) error {
return d.StopTaskF(taskID, timeout, signal)
}
func (d *MockDriver) DestroyTask(taskID string, force bool) error {
return d.DestroyTaskF(taskID, force)
}
func (d *MockDriver) InspectTask(taskID string) (*drivers.TaskStatus, error) {
return d.InspectTaskF(taskID)
}
func (d *MockDriver) TaskStats(ctx context.Context, taskID string, i time.Duration) (<-chan *drivers.TaskResourceUsage, error) {
return d.TaskStatsF(ctx, taskID, i)
}
func (d *MockDriver) TaskEvents(ctx context.Context) (<-chan *drivers.TaskEvent, error) {
return d.TaskEventsF(ctx)
}
func (d *MockDriver) SignalTask(taskID string, signal string) error {
return d.SignalTaskF(taskID, signal)
}
func (d *MockDriver) ExecTask(taskID string, cmd []string, timeout time.Duration) (*drivers.ExecTaskResult, error) {
return d.ExecTaskF(taskID, cmd, timeout)
}
func (d *MockDriver) ExecTaskStreaming(ctx context.Context, taskID string, execOpts *drivers.ExecOptions) (*drivers.ExitResult, error) {
return d.ExecTaskStreamingF(ctx, taskID, execOpts)
}
// SetEnvvars sets path and host env vars depending on the FS isolation used.
func SetEnvvars(envBuilder *taskenv.Builder, fsi drivers.FSIsolation, taskDir *allocdir.TaskDir, conf *config.Config) {
envBuilder.SetClientTaskRoot(taskDir.Dir)
envBuilder.SetClientSharedAllocDir(taskDir.SharedAllocDir)
envBuilder.SetClientTaskLocalDir(taskDir.LocalDir)
envBuilder.SetClientTaskSecretsDir(taskDir.SecretsDir)
// Set driver-specific environment variables
switch fsi {
case drivers.FSIsolationNone:
// Use host paths
envBuilder.SetAllocDir(taskDir.SharedAllocDir)
envBuilder.SetTaskLocalDir(taskDir.LocalDir)
envBuilder.SetSecretsDir(taskDir.SecretsDir)
default:
// filesystem isolation; use container paths
envBuilder.SetAllocDir(allocdir.SharedAllocContainerPath)
envBuilder.SetTaskLocalDir(allocdir.TaskLocalContainerPath)
envBuilder.SetSecretsDir(allocdir.TaskSecretsContainerPath)
}
// Set the host environment variables for non-image based drivers
if fsi != drivers.FSIsolationImage {
// COMPAT(1.0) using inclusive language, blacklist is kept for backward compatibility.
filter := strings.Split(conf.ReadAlternativeDefault(
[]string{"env.denylist", "env.blacklist"},
config.DefaultEnvDenylist,
), ",")
envBuilder.SetHostEnvvars(filter)
}
}