1
0
Fork 0
mirror of https://github.com/moby/moby.git synced 2022-11-09 12:21:53 -05:00
moby--moby/plugin/manager_linux.go
Kir Kolyshkin 6533136961 pkg/mount: wrap mount/umount errors
The errors returned from Mount and Unmount functions are raw
syscall.Errno errors (like EPERM or EINVAL), which provides
no context about what has happened and why.

Similar to os.PathError type, introduce mount.Error type
with some context. The error messages will now look like this:

> mount /tmp/mount-tests/source:/tmp/mount-tests/target, flags: 0x1001: operation not permitted

or

> mount tmpfs:/tmp/mount-test-source-516297835: operation not permitted

Before this patch, it was just

> operation not permitted

[v2: add Cause()]
[v3: rename MountError to Error, document Cause()]
[v4: fixes; audited all users]
[v5: make Error type private; changes after @cpuguy83 reviews]

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
2018-12-10 20:07:02 -08:00

335 lines
9.4 KiB
Go

package plugin // import "github.com/docker/docker/plugin"
import (
"encoding/json"
"net"
"os"
"path/filepath"
"time"
"github.com/docker/docker/api/types"
"github.com/docker/docker/daemon/initlayer"
"github.com/docker/docker/errdefs"
"github.com/docker/docker/pkg/containerfs"
"github.com/docker/docker/pkg/idtools"
"github.com/docker/docker/pkg/mount"
"github.com/docker/docker/pkg/plugins"
"github.com/docker/docker/pkg/stringid"
"github.com/docker/docker/plugin/v2"
"github.com/opencontainers/go-digest"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
)
func (pm *Manager) enable(p *v2.Plugin, c *controller, force bool) error {
p.Rootfs = filepath.Join(pm.config.Root, p.PluginObj.ID, "rootfs")
if p.IsEnabled() && !force {
return errors.Wrap(enabledError(p.Name()), "plugin already enabled")
}
spec, err := p.InitSpec(pm.config.ExecRoot)
if err != nil {
return err
}
c.restart = true
c.exitChan = make(chan bool)
pm.mu.Lock()
pm.cMap[p] = c
pm.mu.Unlock()
var propRoot string
if p.PluginObj.Config.PropagatedMount != "" {
propRoot = filepath.Join(filepath.Dir(p.Rootfs), "propagated-mount")
if err := os.MkdirAll(propRoot, 0755); err != nil {
logrus.Errorf("failed to create PropagatedMount directory at %s: %v", propRoot, err)
}
if err := mount.MakeRShared(propRoot); err != nil {
return errors.Wrap(err, "error setting up propagated mount dir")
}
}
rootFS := containerfs.NewLocalContainerFS(filepath.Join(pm.config.Root, p.PluginObj.ID, rootFSFileName))
if err := initlayer.Setup(rootFS, idtools.Identity{UID: 0, GID: 0}); err != nil {
return errors.WithStack(err)
}
stdout, stderr := makeLoggerStreams(p.GetID())
if err := pm.executor.Create(p.GetID(), *spec, stdout, stderr); err != nil {
if p.PluginObj.Config.PropagatedMount != "" {
if err := mount.Unmount(propRoot); err != nil {
logrus.WithField("plugin", p.Name()).WithError(err).Warn("Failed to unmount vplugin propagated mount root")
}
}
return errors.WithStack(err)
}
return pm.pluginPostStart(p, c)
}
func (pm *Manager) pluginPostStart(p *v2.Plugin, c *controller) error {
sockAddr := filepath.Join(pm.config.ExecRoot, p.GetID(), p.GetSocket())
p.SetTimeout(time.Duration(c.timeoutInSecs) * time.Second)
addr := &net.UnixAddr{Net: "unix", Name: sockAddr}
p.SetAddr(addr)
if p.Protocol() == plugins.ProtocolSchemeHTTPV1 {
client, err := plugins.NewClientWithTimeout(addr.Network()+"://"+addr.String(), nil, p.Timeout())
if err != nil {
c.restart = false
shutdownPlugin(p, c.exitChan, pm.executor)
return errors.WithStack(err)
}
p.SetPClient(client)
}
// Initial sleep before net Dial to allow plugin to listen on socket.
time.Sleep(500 * time.Millisecond)
maxRetries := 3
var retries int
for {
// net dial into the unix socket to see if someone's listening.
conn, err := net.Dial("unix", sockAddr)
if err == nil {
conn.Close()
break
}
time.Sleep(3 * time.Second)
retries++
if retries > maxRetries {
logrus.Debugf("error net dialing plugin: %v", err)
c.restart = false
// While restoring plugins, we need to explicitly set the state to disabled
pm.config.Store.SetState(p, false)
shutdownPlugin(p, c.exitChan, pm.executor)
return err
}
}
pm.config.Store.SetState(p, true)
pm.config.Store.CallHandler(p)
return pm.save(p)
}
func (pm *Manager) restore(p *v2.Plugin, c *controller) error {
stdout, stderr := makeLoggerStreams(p.GetID())
alive, err := pm.executor.Restore(p.GetID(), stdout, stderr)
if err != nil {
return err
}
if pm.config.LiveRestoreEnabled {
if !alive {
return pm.enable(p, c, true)
}
c.exitChan = make(chan bool)
c.restart = true
pm.mu.Lock()
pm.cMap[p] = c
pm.mu.Unlock()
return pm.pluginPostStart(p, c)
}
if alive {
// TODO(@cpuguy83): Should we always just re-attach to the running plugin instead of doing this?
c.restart = false
shutdownPlugin(p, c.exitChan, pm.executor)
}
return nil
}
func shutdownPlugin(p *v2.Plugin, ec chan bool, executor Executor) {
pluginID := p.GetID()
err := executor.Signal(pluginID, int(unix.SIGTERM))
if err != nil {
logrus.Errorf("Sending SIGTERM to plugin failed with error: %v", err)
} else {
select {
case <-ec:
logrus.Debug("Clean shutdown of plugin")
case <-time.After(time.Second * 10):
logrus.Debug("Force shutdown plugin")
if err := executor.Signal(pluginID, int(unix.SIGKILL)); err != nil {
logrus.Errorf("Sending SIGKILL to plugin failed with error: %v", err)
}
select {
case <-ec:
logrus.Debug("SIGKILL plugin shutdown")
case <-time.After(time.Second * 10):
logrus.Debug("Force shutdown plugin FAILED")
}
}
}
}
func (pm *Manager) disable(p *v2.Plugin, c *controller) error {
if !p.IsEnabled() {
return errors.Wrap(errDisabled(p.Name()), "plugin is already disabled")
}
c.restart = false
shutdownPlugin(p, c.exitChan, pm.executor)
pm.config.Store.SetState(p, false)
return pm.save(p)
}
// Shutdown stops all plugins and called during daemon shutdown.
func (pm *Manager) Shutdown() {
plugins := pm.config.Store.GetAll()
for _, p := range plugins {
pm.mu.RLock()
c := pm.cMap[p]
pm.mu.RUnlock()
if pm.config.LiveRestoreEnabled && p.IsEnabled() {
logrus.Debug("Plugin active when liveRestore is set, skipping shutdown")
continue
}
if pm.executor != nil && p.IsEnabled() {
c.restart = false
shutdownPlugin(p, c.exitChan, pm.executor)
}
}
if err := mount.RecursiveUnmount(pm.config.Root); err != nil {
logrus.WithError(err).Warn("error cleaning up plugin mounts")
}
}
func (pm *Manager) upgradePlugin(p *v2.Plugin, configDigest digest.Digest, blobsums []digest.Digest, tmpRootFSDir string, privileges *types.PluginPrivileges) (err error) {
config, err := pm.setupNewPlugin(configDigest, blobsums, privileges)
if err != nil {
return err
}
pdir := filepath.Join(pm.config.Root, p.PluginObj.ID)
orig := filepath.Join(pdir, "rootfs")
// Make sure nothing is mounted
// This could happen if the plugin was disabled with `-f` with active mounts.
// If there is anything in `orig` is still mounted, this should error out.
if err := mount.RecursiveUnmount(orig); err != nil {
return errdefs.System(err)
}
backup := orig + "-old"
if err := os.Rename(orig, backup); err != nil {
return errors.Wrap(errdefs.System(err), "error backing up plugin data before upgrade")
}
defer func() {
if err != nil {
if rmErr := os.RemoveAll(orig); rmErr != nil && !os.IsNotExist(rmErr) {
logrus.WithError(rmErr).WithField("dir", backup).Error("error cleaning up after failed upgrade")
return
}
if mvErr := os.Rename(backup, orig); mvErr != nil {
err = errors.Wrap(mvErr, "error restoring old plugin root on upgrade failure")
}
if rmErr := os.RemoveAll(tmpRootFSDir); rmErr != nil && !os.IsNotExist(rmErr) {
logrus.WithError(rmErr).WithField("plugin", p.Name()).Errorf("error cleaning up plugin upgrade dir: %s", tmpRootFSDir)
}
} else {
if rmErr := os.RemoveAll(backup); rmErr != nil && !os.IsNotExist(rmErr) {
logrus.WithError(rmErr).WithField("dir", backup).Error("error cleaning up old plugin root after successful upgrade")
}
p.Config = configDigest
p.Blobsums = blobsums
}
}()
if err := os.Rename(tmpRootFSDir, orig); err != nil {
return errors.Wrap(errdefs.System(err), "error upgrading")
}
p.PluginObj.Config = config
err = pm.save(p)
return errors.Wrap(err, "error saving upgraded plugin config")
}
func (pm *Manager) setupNewPlugin(configDigest digest.Digest, blobsums []digest.Digest, privileges *types.PluginPrivileges) (types.PluginConfig, error) {
configRC, err := pm.blobStore.Get(configDigest)
if err != nil {
return types.PluginConfig{}, err
}
defer configRC.Close()
var config types.PluginConfig
dec := json.NewDecoder(configRC)
if err := dec.Decode(&config); err != nil {
return types.PluginConfig{}, errors.Wrapf(err, "failed to parse config")
}
if dec.More() {
return types.PluginConfig{}, errors.New("invalid config json")
}
requiredPrivileges := computePrivileges(config)
if err != nil {
return types.PluginConfig{}, err
}
if privileges != nil {
if err := validatePrivileges(requiredPrivileges, *privileges); err != nil {
return types.PluginConfig{}, err
}
}
return config, nil
}
// createPlugin creates a new plugin. take lock before calling.
func (pm *Manager) createPlugin(name string, configDigest digest.Digest, blobsums []digest.Digest, rootFSDir string, privileges *types.PluginPrivileges, opts ...CreateOpt) (p *v2.Plugin, err error) {
if err := pm.config.Store.validateName(name); err != nil { // todo: this check is wrong. remove store
return nil, errdefs.InvalidParameter(err)
}
config, err := pm.setupNewPlugin(configDigest, blobsums, privileges)
if err != nil {
return nil, err
}
p = &v2.Plugin{
PluginObj: types.Plugin{
Name: name,
ID: stringid.GenerateRandomID(),
Config: config,
},
Config: configDigest,
Blobsums: blobsums,
}
p.InitEmptySettings()
for _, o := range opts {
o(p)
}
pdir := filepath.Join(pm.config.Root, p.PluginObj.ID)
if err := os.MkdirAll(pdir, 0700); err != nil {
return nil, errors.Wrapf(err, "failed to mkdir %v", pdir)
}
defer func() {
if err != nil {
os.RemoveAll(pdir)
}
}()
if err := os.Rename(rootFSDir, filepath.Join(pdir, rootFSFileName)); err != nil {
return nil, errors.Wrap(err, "failed to rename rootfs")
}
if err := pm.save(p); err != nil {
return nil, err
}
pm.config.Store.Add(p) // todo: remove
return p, nil
}