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moby--moby/daemon/daemon.go

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// Package daemon exposes the functions that occur on the host server
// that the Docker daemon is running.
//
// In implementing the various functions of the daemon, there is often
// a method-specific struct for configuring the runtime behavior.
package daemon
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import (
"encoding/json"
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"fmt"
"io"
"io/ioutil"
"net"
"os"
"path"
"path/filepath"
"runtime"
Remove static errors from errors package. Moving all strings to the errors package wasn't a good idea after all. Our custom implementation of Go errors predates everything that's nice and good about working with errors in Go. Take as an example what we have to do to get an error message: ```go func GetErrorMessage(err error) string { switch err.(type) { case errcode.Error: e, _ := err.(errcode.Error) return e.Message case errcode.ErrorCode: ec, _ := err.(errcode.ErrorCode) return ec.Message() default: return err.Error() } } ``` This goes against every good practice for Go development. The language already provides a simple, intuitive and standard way to get error messages, that is calling the `Error()` method from an error. Reinventing the error interface is a mistake. Our custom implementation also makes very hard to reason about errors, another nice thing about Go. I found several (>10) error declarations that we don't use anywhere. This is a clear sign about how little we know about the errors we return. I also found several error usages where the number of arguments was different than the parameters declared in the error, another clear example of how difficult is to reason about errors. Moreover, our custom implementation didn't really make easier for people to return custom HTTP status code depending on the errors. Again, it's hard to reason about when to set custom codes and how. Take an example what we have to do to extract the message and status code from an error before returning a response from the API: ```go switch err.(type) { case errcode.ErrorCode: daError, _ := err.(errcode.ErrorCode) statusCode = daError.Descriptor().HTTPStatusCode errMsg = daError.Message() case errcode.Error: // For reference, if you're looking for a particular error // then you can do something like : // import ( derr "github.com/docker/docker/errors" ) // if daError.ErrorCode() == derr.ErrorCodeNoSuchContainer { ... } daError, _ := err.(errcode.Error) statusCode = daError.ErrorCode().Descriptor().HTTPStatusCode errMsg = daError.Message default: // This part of will be removed once we've // converted everything over to use the errcode package // FIXME: this is brittle and should not be necessary. // If we need to differentiate between different possible error types, // we should create appropriate error types with clearly defined meaning errStr := strings.ToLower(err.Error()) for keyword, status := range map[string]int{ "not found": http.StatusNotFound, "no such": http.StatusNotFound, "bad parameter": http.StatusBadRequest, "conflict": http.StatusConflict, "impossible": http.StatusNotAcceptable, "wrong login/password": http.StatusUnauthorized, "hasn't been activated": http.StatusForbidden, } { if strings.Contains(errStr, keyword) { statusCode = status break } } } ``` You can notice two things in that code: 1. We have to explain how errors work, because our implementation goes against how easy to use Go errors are. 2. At no moment we arrived to remove that `switch` statement that was the original reason to use our custom implementation. This change removes all our status errors from the errors package and puts them back in their specific contexts. IT puts the messages back with their contexts. That way, we know right away when errors used and how to generate their messages. It uses custom interfaces to reason about errors. Errors that need to response with a custom status code MUST implementent this simple interface: ```go type errorWithStatus interface { HTTPErrorStatusCode() int } ``` This interface is very straightforward to implement. It also preserves Go errors real behavior, getting the message is as simple as using the `Error()` method. I included helper functions to generate errors that use custom status code in `errors/errors.go`. By doing this, we remove the hard dependency we have eeverywhere to our custom errors package. Yes, you can use it as a helper to generate error, but it's still very easy to generate errors without it. Please, read this fantastic blog post about errors in Go: http://dave.cheney.net/2014/12/24/inspecting-errors Signed-off-by: David Calavera <david.calavera@gmail.com>
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"strings"
"sync"
"syscall"
"time"
"github.com/Sirupsen/logrus"
containerd "github.com/docker/containerd/api/grpc/types"
"github.com/docker/docker/api"
"github.com/docker/docker/api/types"
containertypes "github.com/docker/docker/api/types/container"
"github.com/docker/docker/container"
"github.com/docker/docker/daemon/events"
"github.com/docker/docker/daemon/exec"
"github.com/docker/libnetwork/cluster"
// register graph drivers
_ "github.com/docker/docker/daemon/graphdriver/register"
dmetadata "github.com/docker/docker/distribution/metadata"
"github.com/docker/docker/distribution/xfer"
"github.com/docker/docker/image"
"github.com/docker/docker/layer"
"github.com/docker/docker/libcontainerd"
"github.com/docker/docker/migrate/v1"
"github.com/docker/docker/pkg/fileutils"
"github.com/docker/docker/pkg/graphdb"
"github.com/docker/docker/pkg/idtools"
"github.com/docker/docker/pkg/progress"
"github.com/docker/docker/pkg/registrar"
"github.com/docker/docker/pkg/signal"
"github.com/docker/docker/pkg/streamformatter"
"github.com/docker/docker/pkg/sysinfo"
"github.com/docker/docker/pkg/system"
"github.com/docker/docker/pkg/truncindex"
"github.com/docker/docker/reference"
"github.com/docker/docker/registry"
"github.com/docker/docker/runconfig"
"github.com/docker/docker/utils"
volumedrivers "github.com/docker/docker/volume/drivers"
"github.com/docker/docker/volume/local"
"github.com/docker/docker/volume/store"
"github.com/docker/libnetwork"
nwconfig "github.com/docker/libnetwork/config"
"github.com/docker/libtrust"
)
var (
// DefaultRuntimeBinary is the default runtime to be used by
// containerd if none is specified
DefaultRuntimeBinary = "docker-runc"
Remove static errors from errors package. Moving all strings to the errors package wasn't a good idea after all. Our custom implementation of Go errors predates everything that's nice and good about working with errors in Go. Take as an example what we have to do to get an error message: ```go func GetErrorMessage(err error) string { switch err.(type) { case errcode.Error: e, _ := err.(errcode.Error) return e.Message case errcode.ErrorCode: ec, _ := err.(errcode.ErrorCode) return ec.Message() default: return err.Error() } } ``` This goes against every good practice for Go development. The language already provides a simple, intuitive and standard way to get error messages, that is calling the `Error()` method from an error. Reinventing the error interface is a mistake. Our custom implementation also makes very hard to reason about errors, another nice thing about Go. I found several (>10) error declarations that we don't use anywhere. This is a clear sign about how little we know about the errors we return. I also found several error usages where the number of arguments was different than the parameters declared in the error, another clear example of how difficult is to reason about errors. Moreover, our custom implementation didn't really make easier for people to return custom HTTP status code depending on the errors. Again, it's hard to reason about when to set custom codes and how. Take an example what we have to do to extract the message and status code from an error before returning a response from the API: ```go switch err.(type) { case errcode.ErrorCode: daError, _ := err.(errcode.ErrorCode) statusCode = daError.Descriptor().HTTPStatusCode errMsg = daError.Message() case errcode.Error: // For reference, if you're looking for a particular error // then you can do something like : // import ( derr "github.com/docker/docker/errors" ) // if daError.ErrorCode() == derr.ErrorCodeNoSuchContainer { ... } daError, _ := err.(errcode.Error) statusCode = daError.ErrorCode().Descriptor().HTTPStatusCode errMsg = daError.Message default: // This part of will be removed once we've // converted everything over to use the errcode package // FIXME: this is brittle and should not be necessary. // If we need to differentiate between different possible error types, // we should create appropriate error types with clearly defined meaning errStr := strings.ToLower(err.Error()) for keyword, status := range map[string]int{ "not found": http.StatusNotFound, "no such": http.StatusNotFound, "bad parameter": http.StatusBadRequest, "conflict": http.StatusConflict, "impossible": http.StatusNotAcceptable, "wrong login/password": http.StatusUnauthorized, "hasn't been activated": http.StatusForbidden, } { if strings.Contains(errStr, keyword) { statusCode = status break } } } ``` You can notice two things in that code: 1. We have to explain how errors work, because our implementation goes against how easy to use Go errors are. 2. At no moment we arrived to remove that `switch` statement that was the original reason to use our custom implementation. This change removes all our status errors from the errors package and puts them back in their specific contexts. IT puts the messages back with their contexts. That way, we know right away when errors used and how to generate their messages. It uses custom interfaces to reason about errors. Errors that need to response with a custom status code MUST implementent this simple interface: ```go type errorWithStatus interface { HTTPErrorStatusCode() int } ``` This interface is very straightforward to implement. It also preserves Go errors real behavior, getting the message is as simple as using the `Error()` method. I included helper functions to generate errors that use custom status code in `errors/errors.go`. By doing this, we remove the hard dependency we have eeverywhere to our custom errors package. Yes, you can use it as a helper to generate error, but it's still very easy to generate errors without it. Please, read this fantastic blog post about errors in Go: http://dave.cheney.net/2014/12/24/inspecting-errors Signed-off-by: David Calavera <david.calavera@gmail.com>
2016-02-25 10:53:35 -05:00
errSystemNotSupported = fmt.Errorf("The Docker daemon is not supported on this platform.")
)
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// Daemon holds information about the Docker daemon.
type Daemon struct {
ID string
repository string
containers container.Store
execCommands *exec.Store
referenceStore reference.Store
downloadManager *xfer.LayerDownloadManager
uploadManager *xfer.LayerUploadManager
distributionMetadataStore dmetadata.Store
trustKey libtrust.PrivateKey
idIndex *truncindex.TruncIndex
configStore *Config
statsCollector *statsCollector
defaultLogConfig containertypes.LogConfig
RegistryService registry.Service
EventsService *events.Events
netController libnetwork.NetworkController
volumes *store.VolumeStore
discoveryWatcher discoveryReloader
root string
seccompEnabled bool
shutdown bool
uidMaps []idtools.IDMap
gidMaps []idtools.IDMap
layerStore layer.Store
imageStore image.Store
nameIndex *registrar.Registrar
linkIndex *linkIndex
containerd libcontainerd.Client
containerdRemote libcontainerd.Remote
defaultIsolation containertypes.Isolation // Default isolation mode on Windows
clusterProvider cluster.Provider
}
func (daemon *Daemon) restore() error {
var (
debug = utils.IsDebugEnabled()
currentDriver = daemon.GraphDriverName()
containers = make(map[string]*container.Container)
)
if !debug {
logrus.Info("Loading containers: start.")
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}
dir, err := ioutil.ReadDir(daemon.repository)
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if err != nil {
return err
}
containerCount := 0
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for _, v := range dir {
id := v.Name()
container, err := daemon.load(id)
if !debug && logrus.GetLevel() == logrus.InfoLevel {
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fmt.Print(".")
containerCount++
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}
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if err != nil {
logrus.Errorf("Failed to load container %v: %v", id, err)
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continue
}
// Ignore the container if it does not support the current driver being used by the graph
if (container.Driver == "" && currentDriver == "aufs") || container.Driver == currentDriver {
rwlayer, err := daemon.layerStore.GetRWLayer(container.ID)
if err != nil {
logrus.Errorf("Failed to load container mount %v: %v", id, err)
continue
}
container.RWLayer = rwlayer
logrus.Debugf("Loaded container %v", container.ID)
containers[container.ID] = container
} else {
logrus.Debugf("Cannot load container %s because it was created with another graph driver.", container.ID)
}
}
var migrateLegacyLinks bool
removeContainers := make(map[string]*container.Container)
restartContainers := make(map[*container.Container]chan struct{})
activeSandboxes := make(map[string]interface{})
for _, c := range containers {
if err := daemon.registerName(c); err != nil {
logrus.Errorf("Failed to register container %s: %s", c.ID, err)
continue
}
if err := daemon.Register(c); err != nil {
logrus.Errorf("Failed to register container %s: %s", c.ID, err)
continue
}
// verify that all volumes valid and have been migrated from the pre-1.7 layout
if err := daemon.verifyVolumesInfo(c); err != nil {
// don't skip the container due to error
logrus.Errorf("Failed to verify volumes for container '%s': %v", c.ID, err)
}
// The LogConfig.Type is empty if the container was created before docker 1.12 with default log driver.
// We should rewrite it to use the daemon defaults.
// Fixes https://github.com/docker/docker/issues/22536
if c.HostConfig.LogConfig.Type == "" {
if err := daemon.mergeAndVerifyLogConfig(&c.HostConfig.LogConfig); err != nil {
logrus.Errorf("Failed to verify log config for container %s: %q", c.ID, err)
continue
}
}
}
var wg sync.WaitGroup
var mapLock sync.Mutex
for _, c := range containers {
wg.Add(1)
go func(c *container.Container) {
defer wg.Done()
rm := c.RestartManager(false)
if c.IsRunning() || c.IsPaused() {
if err := daemon.containerd.Restore(c.ID, libcontainerd.WithRestartManager(rm)); err != nil {
logrus.Errorf("Failed to restore %s with containerd: %s", c.ID, err)
return
}
if !c.HostConfig.NetworkMode.IsContainer() && c.IsRunning() {
options, err := daemon.buildSandboxOptions(c)
if err != nil {
logrus.Warnf("Failed build sandbox option to restore container %s: %v", c.ID, err)
}
mapLock.Lock()
activeSandboxes[c.NetworkSettings.SandboxID] = options
mapLock.Unlock()
}
}
// fixme: only if not running
// get list of containers we need to restart
if !c.IsRunning() && !c.IsPaused() {
if daemon.configStore.AutoRestart && c.ShouldRestart() {
mapLock.Lock()
restartContainers[c] = make(chan struct{})
mapLock.Unlock()
} else if c.HostConfig != nil && c.HostConfig.AutoRemove {
mapLock.Lock()
removeContainers[c.ID] = c
mapLock.Unlock()
}
}
if c.RemovalInProgress {
// We probably crashed in the middle of a removal, reset
// the flag.
//
// We DO NOT remove the container here as we do not
// know if the user had requested for either the
// associated volumes, network links or both to also
// be removed. So we put the container in the "dead"
// state and leave further processing up to them.
logrus.Debugf("Resetting RemovalInProgress flag from %v", c.ID)
c.ResetRemovalInProgress()
c.SetDead()
c.ToDisk()
}
// if c.hostConfig.Links is nil (not just empty), then it is using the old sqlite links and needs to be migrated
if c.HostConfig != nil && c.HostConfig.Links == nil {
migrateLegacyLinks = true
}
}(c)
}
wg.Wait()
daemon.netController, err = daemon.initNetworkController(daemon.configStore, activeSandboxes)
if err != nil {
return fmt.Errorf("Error initializing network controller: %v", err)
}
// migrate any legacy links from sqlite
linkdbFile := filepath.Join(daemon.root, "linkgraph.db")
var legacyLinkDB *graphdb.Database
if migrateLegacyLinks {
legacyLinkDB, err = graphdb.NewSqliteConn(linkdbFile)
if err != nil {
return fmt.Errorf("error connecting to legacy link graph DB %s, container links may be lost: %v", linkdbFile, err)
}
defer legacyLinkDB.Close()
}
// Now that all the containers are registered, register the links
for _, c := range containers {
if migrateLegacyLinks {
if err := daemon.migrateLegacySqliteLinks(legacyLinkDB, c); err != nil {
return err
}
}
if err := daemon.registerLinks(c, c.HostConfig); err != nil {
logrus.Errorf("failed to register link for container %s: %v", c.ID, err)
}
}
group := sync.WaitGroup{}
for c, notifier := range restartContainers {
group.Add(1)
go func(c *container.Container, chNotify chan struct{}) {
defer group.Done()
logrus.Debugf("Starting container %s", c.ID)
// ignore errors here as this is a best effort to wait for children to be
// running before we try to start the container
children := daemon.children(c)
timeout := time.After(5 * time.Second)
for _, child := range children {
if notifier, exists := restartContainers[child]; exists {
select {
case <-notifier:
case <-timeout:
}
}
}
// Make sure networks are available before starting
daemon.waitForNetworks(c)
if err := daemon.containerStart(c, ""); err != nil {
logrus.Errorf("Failed to start container %s: %s", c.ID, err)
}
close(chNotify)
}(c, notifier)
}
group.Wait()
removeGroup := sync.WaitGroup{}
for id := range removeContainers {
removeGroup.Add(1)
go func(cid string) {
if err := daemon.ContainerRm(cid, &types.ContainerRmConfig{ForceRemove: true, RemoveVolume: true}); err != nil {
logrus.Errorf("Failed to remove container %s: %s", cid, err)
}
removeGroup.Done()
}(id)
}
removeGroup.Wait()
// any containers that were started above would already have had this done,
// however we need to now prepare the mountpoints for the rest of the containers as well.
// This shouldn't cause any issue running on the containers that already had this run.
// This must be run after any containers with a restart policy so that containerized plugins
// can have a chance to be running before we try to initialize them.
for _, c := range containers {
// if the container has restart policy, do not
// prepare the mountpoints since it has been done on restarting.
// This is to speed up the daemon start when a restart container
// has a volume and the volume dirver is not available.
if _, ok := restartContainers[c]; ok {
continue
} else if _, ok := removeContainers[c.ID]; ok {
// container is automatically removed, skip it.
continue
}
group.Add(1)
go func(c *container.Container) {
defer group.Done()
if err := daemon.prepareMountPoints(c); err != nil {
logrus.Error(err)
}
}(c)
}
group.Wait()
if !debug {
if logrus.GetLevel() == logrus.InfoLevel && containerCount > 0 {
fmt.Println()
}
logrus.Info("Loading containers: done.")
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}
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return nil
}
// waitForNetworks is used during daemon initialization when starting up containers
// It ensures that all of a container's networks are available before the daemon tries to start the container.
// In practice it just makes sure the discovery service is available for containers which use a network that require discovery.
func (daemon *Daemon) waitForNetworks(c *container.Container) {
if daemon.discoveryWatcher == nil {
return
}
// Make sure if the container has a network that requires discovery that the discovery service is available before starting
for netName := range c.NetworkSettings.Networks {
// If we get `ErrNoSuchNetwork` here, we can assume that it is due to discovery not being ready
// Most likely this is because the K/V store used for discovery is in a container and needs to be started
if _, err := daemon.netController.NetworkByName(netName); err != nil {
if _, ok := err.(libnetwork.ErrNoSuchNetwork); !ok {
continue
}
// use a longish timeout here due to some slowdowns in libnetwork if the k/v store is on anything other than --net=host
// FIXME: why is this slow???
logrus.Debugf("Container %s waiting for network to be ready", c.Name)
select {
case <-daemon.discoveryWatcher.ReadyCh():
case <-time.After(60 * time.Second):
}
return
}
}
}
func (daemon *Daemon) children(c *container.Container) map[string]*container.Container {
return daemon.linkIndex.children(c)
}
// parents returns the names of the parent containers of the container
// with the given name.
func (daemon *Daemon) parents(c *container.Container) map[string]*container.Container {
return daemon.linkIndex.parents(c)
}
func (daemon *Daemon) registerLink(parent, child *container.Container, alias string) error {
fullName := path.Join(parent.Name, alias)
if err := daemon.nameIndex.Reserve(fullName, child.ID); err != nil {
if err == registrar.ErrNameReserved {
logrus.Warnf("error registering link for %s, to %s, as alias %s, ignoring: %v", parent.ID, child.ID, alias, err)
return nil
}
return err
}
daemon.linkIndex.link(parent, child, fullName)
return nil
}
// SetClusterProvider sets a component for querying the current cluster state.
func (daemon *Daemon) SetClusterProvider(clusterProvider cluster.Provider) {
daemon.clusterProvider = clusterProvider
daemon.netController.SetClusterProvider(clusterProvider)
}
// IsSwarmCompatible verifies if the current daemon
// configuration is compatible with the swarm mode
func (daemon *Daemon) IsSwarmCompatible() error {
if daemon.configStore == nil {
return nil
}
return daemon.configStore.isSwarmCompatible()
}
// NewDaemon sets up everything for the daemon to be able to service
// requests from the webserver.
func NewDaemon(config *Config, registryService registry.Service, containerdRemote libcontainerd.Remote) (daemon *Daemon, err error) {
setDefaultMtu(config)
// Ensure that we have a correct root key limit for launching containers.
if err := ModifyRootKeyLimit(); err != nil {
logrus.Warnf("unable to modify root key limit, number of containers could be limitied by this quota: %v", err)
}
// Ensure we have compatible and valid configuration options
if err := verifyDaemonSettings(config); err != nil {
return nil, err
}
// Do we have a disabled network?
config.DisableBridge = isBridgeNetworkDisabled(config)
// Verify the platform is supported as a daemon
if !platformSupported {
return nil, errSystemNotSupported
}
// Validate platform-specific requirements
if err := checkSystem(); err != nil {
return nil, err
}
// set up SIGUSR1 handler on Unix-like systems, or a Win32 global event
// on Windows to dump Go routine stacks
setupDumpStackTrap(config.Root)
uidMaps, gidMaps, err := setupRemappedRoot(config)
if err != nil {
return nil, err
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
// get the canonical path to the Docker root directory
var realRoot string
if _, err := os.Stat(config.Root); err != nil && os.IsNotExist(err) {
realRoot = config.Root
} else {
realRoot, err = fileutils.ReadSymlinkedDirectory(config.Root)
if err != nil {
return nil, fmt.Errorf("Unable to get the full path to root (%s): %s", config.Root, err)
}
}
if err := setupDaemonRoot(config, realRoot, rootUID, rootGID); err != nil {
return nil, err
}
if err := setupDaemonProcess(config); err != nil {
return nil, err
}
// set up the tmpDir to use a canonical path
tmp, err := tempDir(config.Root, rootUID, rootGID)
if err != nil {
return nil, fmt.Errorf("Unable to get the TempDir under %s: %s", config.Root, err)
}
realTmp, err := fileutils.ReadSymlinkedDirectory(tmp)
if err != nil {
return nil, fmt.Errorf("Unable to get the full path to the TempDir (%s): %s", tmp, err)
}
os.Setenv("TMPDIR", realTmp)
d := &Daemon{configStore: config}
// Ensure the daemon is properly shutdown if there is a failure during
// initialization
defer func() {
if err != nil {
if err := d.Shutdown(); err != nil {
logrus.Error(err)
}
}
}()
// Set the default isolation mode (only applicable on Windows)
if err := d.setDefaultIsolation(); err != nil {
return nil, fmt.Errorf("error setting default isolation mode: %v", err)
}
logrus.Debugf("Using default logging driver %s", config.LogConfig.Type)
if err := configureMaxThreads(config); err != nil {
logrus.Warnf("Failed to configure golang's threads limit: %v", err)
}
installDefaultAppArmorProfile()
daemonRepo := filepath.Join(config.Root, "containers")
if err := idtools.MkdirAllAs(daemonRepo, 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {
return nil, err
}
driverName := os.Getenv("DOCKER_DRIVER")
if driverName == "" {
driverName = config.GraphDriver
}
d.layerStore, err = layer.NewStoreFromOptions(layer.StoreOptions{
StorePath: config.Root,
MetadataStorePathTemplate: filepath.Join(config.Root, "image", "%s", "layerdb"),
GraphDriver: driverName,
GraphDriverOptions: config.GraphOptions,
UIDMaps: uidMaps,
GIDMaps: gidMaps,
})
if err != nil {
return nil, err
}
graphDriver := d.layerStore.DriverName()
imageRoot := filepath.Join(config.Root, "image", graphDriver)
// Configure and validate the kernels security support
if err := configureKernelSecuritySupport(config, graphDriver); err != nil {
return nil, err
}
logrus.Debugf("Max Concurrent Downloads: %d", *config.MaxConcurrentDownloads)
d.downloadManager = xfer.NewLayerDownloadManager(d.layerStore, *config.MaxConcurrentDownloads)
logrus.Debugf("Max Concurrent Uploads: %d", *config.MaxConcurrentUploads)
d.uploadManager = xfer.NewLayerUploadManager(*config.MaxConcurrentUploads)
ifs, err := image.NewFSStoreBackend(filepath.Join(imageRoot, "imagedb"))
if err != nil {
return nil, err
}
d.imageStore, err = image.NewImageStore(ifs, d.layerStore)
if err != nil {
return nil, err
}
// Configure the volumes driver
volStore, err := d.configureVolumes(rootUID, rootGID)
if err != nil {
return nil, err
}
trustKey, err := api.LoadOrCreateTrustKey(config.TrustKeyPath)
if err != nil {
return nil, err
}
trustDir := filepath.Join(config.Root, "trust")
Simplify and fix os.MkdirAll() usage TL;DR: check for IsExist(err) after a failed MkdirAll() is both redundant and wrong -- so two reasons to remove it. Quoting MkdirAll documentation: > MkdirAll creates a directory named path, along with any necessary > parents, and returns nil, or else returns an error. If path > is already a directory, MkdirAll does nothing and returns nil. This means two things: 1. If a directory to be created already exists, no error is returned. 2. If the error returned is IsExist (EEXIST), it means there exists a non-directory with the same name as MkdirAll need to use for directory. Example: we want to MkdirAll("a/b"), but file "a" (or "a/b") already exists, so MkdirAll fails. The above is a theory, based on quoted documentation and my UNIX knowledge. 3. In practice, though, current MkdirAll implementation [1] returns ENOTDIR in most of cases described in #2, with the exception when there is a race between MkdirAll and someone else creating the last component of MkdirAll argument as a file. In this very case MkdirAll() will indeed return EEXIST. Because of #1, IsExist check after MkdirAll is not needed. Because of #2 and #3, ignoring IsExist error is just plain wrong, as directory we require is not created. It's cleaner to report the error now. Note this error is all over the tree, I guess due to copy-paste, or trying to follow the same usage pattern as for Mkdir(), or some not quite correct examples on the Internet. [v2: a separate aufs commit is merged into this one] [1] https://github.com/golang/go/blob/f9ed2f75/src/os/path.go Signed-off-by: Kir Kolyshkin <kir@openvz.org>
2015-07-29 19:49:05 -04:00
if err := system.MkdirAll(trustDir, 0700); err != nil {
return nil, err
}
distributionMetadataStore, err := dmetadata.NewFSMetadataStore(filepath.Join(imageRoot, "distribution"))
if err != nil {
return nil, err
}
eventsService := events.New()
referenceStore, err := reference.NewReferenceStore(filepath.Join(imageRoot, "repositories.json"))
if err != nil {
return nil, fmt.Errorf("Couldn't create Tag store repositories: %s", err)
}
migrationStart := time.Now()
if err := v1.Migrate(config.Root, graphDriver, d.layerStore, d.imageStore, referenceStore, distributionMetadataStore); err != nil {
logrus.Errorf("Graph migration failed: %q. Your old graph data was found to be too inconsistent for upgrading to content-addressable storage. Some of the old data was probably not upgraded. We recommend starting over with a clean storage directory if possible.", err)
}
logrus.Infof("Graph migration to content-addressability took %.2f seconds", time.Since(migrationStart).Seconds())
// Discovery is only enabled when the daemon is launched with an address to advertise. When
// initialized, the daemon is registered and we can store the discovery backend as its read-only
if err := d.initDiscovery(config); err != nil {
return nil, err
}
sysInfo := sysinfo.New(false)
// Check if Devices cgroup is mounted, it is hard requirement for container security,
// on Linux.
if runtime.GOOS == "linux" && !sysInfo.CgroupDevicesEnabled {
return nil, fmt.Errorf("Devices cgroup isn't mounted")
}
d.ID = trustKey.PublicKey().KeyID()
d.repository = daemonRepo
d.containers = container.NewMemoryStore()
d.execCommands = exec.NewStore()
d.referenceStore = referenceStore
d.distributionMetadataStore = distributionMetadataStore
d.trustKey = trustKey
d.idIndex = truncindex.NewTruncIndex([]string{})
d.statsCollector = d.newStatsCollector(1 * time.Second)
d.defaultLogConfig = containertypes.LogConfig{
Type: config.LogConfig.Type,
Config: config.LogConfig.Config,
}
d.RegistryService = registryService
d.EventsService = eventsService
d.volumes = volStore
d.root = config.Root
d.uidMaps = uidMaps
d.gidMaps = gidMaps
d.seccompEnabled = sysInfo.Seccomp
d.nameIndex = registrar.NewRegistrar()
d.linkIndex = newLinkIndex()
d.containerdRemote = containerdRemote
go d.execCommandGC()
d.containerd, err = containerdRemote.Client(d)
if err != nil {
return nil, err
}
// Plugin system initialization should happen before restore. Dont change order.
if err := pluginInit(d, config, containerdRemote); err != nil {
return nil, err
}
if err := d.restore(); err != nil {
return nil, err
}
return d, nil
}
func (daemon *Daemon) shutdownContainer(c *container.Container) error {
// TODO(windows): Handle docker restart with paused containers
if c.IsPaused() {
// To terminate a process in freezer cgroup, we should send
// SIGTERM to this process then unfreeze it, and the process will
// force to terminate immediately.
logrus.Debugf("Found container %s is paused, sending SIGTERM before unpausing it", c.ID)
sig, ok := signal.SignalMap["TERM"]
if !ok {
return fmt.Errorf("System does not support SIGTERM")
}
if err := daemon.kill(c, int(sig)); err != nil {
return fmt.Errorf("sending SIGTERM to container %s with error: %v", c.ID, err)
}
if err := daemon.containerUnpause(c); err != nil {
return fmt.Errorf("Failed to unpause container %s with error: %v", c.ID, err)
}
if _, err := c.WaitStop(10 * time.Second); err != nil {
logrus.Debugf("container %s failed to exit in 10 seconds of SIGTERM, sending SIGKILL to force", c.ID)
sig, ok := signal.SignalMap["KILL"]
if !ok {
return fmt.Errorf("System does not support SIGKILL")
}
if err := daemon.kill(c, int(sig)); err != nil {
logrus.Errorf("Failed to SIGKILL container %s", c.ID)
}
c.WaitStop(-1 * time.Second)
return err
}
}
// If container failed to exit in 10 seconds of SIGTERM, then using the force
if err := daemon.containerStop(c, 10); err != nil {
return fmt.Errorf("Failed to stop container %s with error: %v", c.ID, err)
}
c.WaitStop(-1 * time.Second)
return nil
}
// Shutdown stops the daemon.
func (daemon *Daemon) Shutdown() error {
daemon.shutdown = true
// Keep mounts and networking running on daemon shutdown if
// we are to keep containers running and restore them.
pluginShutdown()
if daemon.configStore.LiveRestoreEnabled && daemon.containers != nil {
// check if there are any running containers, if none we should do some cleanup
if ls, err := daemon.Containers(&types.ContainerListOptions{}); len(ls) != 0 || err != nil {
return nil
}
}
if daemon.containers != nil {
logrus.Debug("starting clean shutdown of all containers...")
daemon.containers.ApplyAll(func(c *container.Container) {
if !c.IsRunning() {
return
}
logrus.Debugf("stopping %s", c.ID)
if err := daemon.shutdownContainer(c); err != nil {
logrus.Errorf("Stop container error: %v", err)
return
}
if mountid, err := daemon.layerStore.GetMountID(c.ID); err == nil {
daemon.cleanupMountsByID(mountid)
}
logrus.Debugf("container stopped %s", c.ID)
})
}
// trigger libnetwork Stop only if it's initialized
if daemon.netController != nil {
daemon.netController.Stop()
}
if daemon.layerStore != nil {
if err := daemon.layerStore.Cleanup(); err != nil {
logrus.Errorf("Error during layer Store.Cleanup(): %v", err)
}
}
if err := daemon.cleanupMounts(); err != nil {
return err
}
return nil
}
// Mount sets container.BaseFS
// (is it not set coming in? why is it unset?)
func (daemon *Daemon) Mount(container *container.Container) error {
dir, err := container.RWLayer.Mount(container.GetMountLabel())
if err != nil {
return err
}
logrus.Debugf("container mounted via layerStore: %v", dir)
if container.BaseFS != dir {
// The mount path reported by the graph driver should always be trusted on Windows, since the
// volume path for a given mounted layer may change over time. This should only be an error
// on non-Windows operating systems.
if container.BaseFS != "" && runtime.GOOS != "windows" {
daemon.Unmount(container)
return fmt.Errorf("Error: driver %s is returning inconsistent paths for container %s ('%s' then '%s')",
daemon.GraphDriverName(), container.ID, container.BaseFS, dir)
}
}
container.BaseFS = dir // TODO: combine these fields
return nil
}
// Unmount unsets the container base filesystem
func (daemon *Daemon) Unmount(container *container.Container) error {
if err := container.RWLayer.Unmount(); err != nil {
logrus.Errorf("Error unmounting container %s: %s", container.ID, err)
return err
}
return nil
}
Split advertised address from listen address There are currently problems with "swarm init" and "swarm join" when an explicit --listen-addr flag is not provided. swarmkit defaults to finding the IP address associated with the default route, and in cloud setups this is often the wrong choice. Introduce a notion of "advertised address", with the client flag --advertise-addr, and the daemon flag --swarm-default-advertise-addr to provide a default. The default listening address is now 0.0.0.0, but a valid advertised address must be detected or specified. If no explicit advertised address is specified, error out if there is more than one usable candidate IP address on the system. This requires a user to explicitly choose instead of letting swarmkit make the wrong choice. For the purposes of this autodetection, we ignore certain interfaces that are unlikely to be relevant (currently docker*). The user is also required to choose a listen address on swarm init if they specify an explicit advertise address that is a hostname or an IP address that's not local to the system. This is a requirement for overlay networking. Also support specifying interface names to --listen-addr, --advertise-addr, and the daemon flag --swarm-default-advertise-addr. This will fail if the interface has multiple IP addresses (unless it has a single IPv4 address and a single IPv6 address - then we resolve the tie in favor of IPv4). This change also exposes the node's externally-reachable address in docker info, as requested by #24017. Make corresponding API and CLI docs changes. Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
2016-06-30 21:07:35 -04:00
// V4Subnets returns the IPv4 subnets of networks that are managed by Docker.
func (daemon *Daemon) V4Subnets() []net.IPNet {
var subnets []net.IPNet
managedNetworks := daemon.netController.Networks()
for _, managedNetwork := range managedNetworks {
v4Infos, _ := managedNetwork.Info().IpamInfo()
for _, v4Info := range v4Infos {
if v4Info.IPAMData.Pool != nil {
subnets = append(subnets, *v4Info.IPAMData.Pool)
}
}
}
return subnets
}
// V6Subnets returns the IPv6 subnets of networks that are managed by Docker.
func (daemon *Daemon) V6Subnets() []net.IPNet {
var subnets []net.IPNet
managedNetworks := daemon.netController.Networks()
for _, managedNetwork := range managedNetworks {
_, v6Infos := managedNetwork.Info().IpamInfo()
for _, v6Info := range v6Infos {
if v6Info.IPAMData.Pool != nil {
subnets = append(subnets, *v6Info.IPAMData.Pool)
}
}
}
return subnets
}
func writeDistributionProgress(cancelFunc func(), outStream io.Writer, progressChan <-chan progress.Progress) {
progressOutput := streamformatter.NewJSONStreamFormatter().NewProgressOutput(outStream, false)
operationCancelled := false
for prog := range progressChan {
if err := progressOutput.WriteProgress(prog); err != nil && !operationCancelled {
// don't log broken pipe errors as this is the normal case when a client aborts
if isBrokenPipe(err) {
logrus.Info("Pull session cancelled")
} else {
logrus.Errorf("error writing progress to client: %v", err)
}
cancelFunc()
operationCancelled = true
// Don't return, because we need to continue draining
// progressChan until it's closed to avoid a deadlock.
}
}
}
func isBrokenPipe(e error) bool {
if netErr, ok := e.(*net.OpError); ok {
e = netErr.Err
if sysErr, ok := netErr.Err.(*os.SyscallError); ok {
e = sysErr.Err
}
}
return e == syscall.EPIPE
}
// GraphDriverName returns the name of the graph driver used by the layer.Store
func (daemon *Daemon) GraphDriverName() string {
return daemon.layerStore.DriverName()
}
// GetUIDGIDMaps returns the current daemon's user namespace settings
// for the full uid and gid maps which will be applied to containers
// started in this instance.
func (daemon *Daemon) GetUIDGIDMaps() ([]idtools.IDMap, []idtools.IDMap) {
return daemon.uidMaps, daemon.gidMaps
}
// GetRemappedUIDGID returns the current daemon's uid and gid values
// if user namespaces are in use for this daemon instance. If not
// this function will return "real" root values of 0, 0.
func (daemon *Daemon) GetRemappedUIDGID() (int, int) {
uid, gid, _ := idtools.GetRootUIDGID(daemon.uidMaps, daemon.gidMaps)
return uid, gid
}
// tempDir returns the default directory to use for temporary files.
func tempDir(rootDir string, rootUID, rootGID int) (string, error) {
var tmpDir string
if tmpDir = os.Getenv("DOCKER_TMPDIR"); tmpDir == "" {
tmpDir = filepath.Join(rootDir, "tmp")
}
return tmpDir, idtools.MkdirAllAs(tmpDir, 0700, rootUID, rootGID)
}
func (daemon *Daemon) setupInitLayer(initPath string) error {
rootUID, rootGID := daemon.GetRemappedUIDGID()
return setupInitLayer(initPath, rootUID, rootGID)
}
func setDefaultMtu(config *Config) {
// do nothing if the config does not have the default 0 value.
if config.Mtu != 0 {
return
}
config.Mtu = defaultNetworkMtu
}
func (daemon *Daemon) configureVolumes(rootUID, rootGID int) (*store.VolumeStore, error) {
volumesDriver, err := local.New(daemon.configStore.Root, rootUID, rootGID)
if err != nil {
return nil, err
}
if !volumedrivers.Register(volumesDriver, volumesDriver.Name()) {
return nil, fmt.Errorf("local volume driver could not be registered")
}
return store.New(daemon.configStore.Root)
}
// IsShuttingDown tells whether the daemon is shutting down or not
func (daemon *Daemon) IsShuttingDown() bool {
return daemon.shutdown
}
// initDiscovery initializes the discovery watcher for this daemon.
func (daemon *Daemon) initDiscovery(config *Config) error {
advertise, err := parseClusterAdvertiseSettings(config.ClusterStore, config.ClusterAdvertise)
if err != nil {
if err == errDiscoveryDisabled {
return nil
}
return err
}
config.ClusterAdvertise = advertise
discoveryWatcher, err := initDiscovery(config.ClusterStore, config.ClusterAdvertise, config.ClusterOpts)
if err != nil {
return fmt.Errorf("discovery initialization failed (%v)", err)
}
daemon.discoveryWatcher = discoveryWatcher
return nil
}
// Reload reads configuration changes and modifies the
// daemon according to those changes.
// These are the settings that Reload changes:
// - Daemon labels.
// - Daemon debug log level.
// - Daemon max concurrent downloads
// - Daemon max concurrent uploads
// - Cluster discovery (reconfigure and restart).
// - Daemon live restore
func (daemon *Daemon) Reload(config *Config) error {
var err error
// used to hold reloaded changes
attributes := map[string]string{}
// We need defer here to ensure the lock is released as
// daemon.SystemInfo() will try to get it too
defer func() {
if err == nil {
daemon.LogDaemonEventWithAttributes("reload", attributes)
}
}()
daemon.configStore.reloadLock.Lock()
defer daemon.configStore.reloadLock.Unlock()
daemon.platformReload(config, &attributes)
if err = daemon.reloadClusterDiscovery(config); err != nil {
return err
}
if config.IsValueSet("labels") {
daemon.configStore.Labels = config.Labels
}
if config.IsValueSet("debug") {
daemon.configStore.Debug = config.Debug
}
if config.IsValueSet("live-restore") {
daemon.configStore.LiveRestoreEnabled = config.LiveRestoreEnabled
if err := daemon.containerdRemote.UpdateOptions(libcontainerd.WithLiveRestore(config.LiveRestoreEnabled)); err != nil {
return err
}
}
// If no value is set for max-concurrent-downloads we assume it is the default value
// We always "reset" as the cost is lightweight and easy to maintain.
if config.IsValueSet("max-concurrent-downloads") && config.MaxConcurrentDownloads != nil {
*daemon.configStore.MaxConcurrentDownloads = *config.MaxConcurrentDownloads
} else {
maxConcurrentDownloads := defaultMaxConcurrentDownloads
daemon.configStore.MaxConcurrentDownloads = &maxConcurrentDownloads
}
logrus.Debugf("Reset Max Concurrent Downloads: %d", *daemon.configStore.MaxConcurrentDownloads)
if daemon.downloadManager != nil {
daemon.downloadManager.SetConcurrency(*daemon.configStore.MaxConcurrentDownloads)
}
// If no value is set for max-concurrent-upload we assume it is the default value
// We always "reset" as the cost is lightweight and easy to maintain.
if config.IsValueSet("max-concurrent-uploads") && config.MaxConcurrentUploads != nil {
*daemon.configStore.MaxConcurrentUploads = *config.MaxConcurrentUploads
} else {
maxConcurrentUploads := defaultMaxConcurrentUploads
daemon.configStore.MaxConcurrentUploads = &maxConcurrentUploads
}
logrus.Debugf("Reset Max Concurrent Uploads: %d", *daemon.configStore.MaxConcurrentUploads)
if daemon.uploadManager != nil {
daemon.uploadManager.SetConcurrency(*daemon.configStore.MaxConcurrentUploads)
}
// We emit daemon reload event here with updatable configurations
attributes["debug"] = fmt.Sprintf("%t", daemon.configStore.Debug)
attributes["live-restore"] = fmt.Sprintf("%t", daemon.configStore.LiveRestoreEnabled)
attributes["cluster-store"] = daemon.configStore.ClusterStore
if daemon.configStore.ClusterOpts != nil {
opts, _ := json.Marshal(daemon.configStore.ClusterOpts)
attributes["cluster-store-opts"] = string(opts)
} else {
attributes["cluster-store-opts"] = "{}"
}
attributes["cluster-advertise"] = daemon.configStore.ClusterAdvertise
if daemon.configStore.Labels != nil {
labels, _ := json.Marshal(daemon.configStore.Labels)
attributes["labels"] = string(labels)
} else {
attributes["labels"] = "[]"
}
attributes["max-concurrent-downloads"] = fmt.Sprintf("%d", *daemon.configStore.MaxConcurrentDownloads)
attributes["max-concurrent-uploads"] = fmt.Sprintf("%d", *daemon.configStore.MaxConcurrentUploads)
return nil
}
func (daemon *Daemon) reloadClusterDiscovery(config *Config) error {
var err error
newAdvertise := daemon.configStore.ClusterAdvertise
newClusterStore := daemon.configStore.ClusterStore
if config.IsValueSet("cluster-advertise") {
if config.IsValueSet("cluster-store") {
newClusterStore = config.ClusterStore
}
newAdvertise, err = parseClusterAdvertiseSettings(newClusterStore, config.ClusterAdvertise)
if err != nil && err != errDiscoveryDisabled {
return err
}
}
if daemon.clusterProvider != nil {
if err := config.isSwarmCompatible(); err != nil {
return err
}
}
// check discovery modifications
if !modifiedDiscoverySettings(daemon.configStore, newAdvertise, newClusterStore, config.ClusterOpts) {
return nil
}
// enable discovery for the first time if it was not previously enabled
if daemon.discoveryWatcher == nil {
discoveryWatcher, err := initDiscovery(newClusterStore, newAdvertise, config.ClusterOpts)
if err != nil {
return fmt.Errorf("discovery initialization failed (%v)", err)
}
daemon.discoveryWatcher = discoveryWatcher
} else {
if err == errDiscoveryDisabled {
// disable discovery if it was previously enabled and it's disabled now
daemon.discoveryWatcher.Stop()
} else {
// reload discovery
if err = daemon.discoveryWatcher.Reload(config.ClusterStore, newAdvertise, config.ClusterOpts); err != nil {
return err
}
}
}
daemon.configStore.ClusterStore = newClusterStore
daemon.configStore.ClusterOpts = config.ClusterOpts
daemon.configStore.ClusterAdvertise = newAdvertise
if daemon.netController == nil {
return nil
}
netOptions, err := daemon.networkOptions(daemon.configStore, nil)
if err != nil {
logrus.Warnf("Failed to reload configuration with network controller: %v", err)
return nil
}
err = daemon.netController.ReloadConfiguration(netOptions...)
if err != nil {
logrus.Warnf("Failed to reload configuration with network controller: %v", err)
}
return nil
}
func isBridgeNetworkDisabled(config *Config) bool {
return config.bridgeConfig.Iface == disableNetworkBridge
}
func (daemon *Daemon) networkOptions(dconfig *Config, activeSandboxes map[string]interface{}) ([]nwconfig.Option, error) {
options := []nwconfig.Option{}
if dconfig == nil {
return options, nil
}
options = append(options, nwconfig.OptionDataDir(dconfig.Root))
options = append(options, nwconfig.OptionExecRoot(dconfig.GetExecRoot()))
dd := runconfig.DefaultDaemonNetworkMode()
dn := runconfig.DefaultDaemonNetworkMode().NetworkName()
options = append(options, nwconfig.OptionDefaultDriver(string(dd)))
options = append(options, nwconfig.OptionDefaultNetwork(dn))
if strings.TrimSpace(dconfig.ClusterStore) != "" {
kv := strings.Split(dconfig.ClusterStore, "://")
if len(kv) != 2 {
return nil, fmt.Errorf("kv store daemon config must be of the form KV-PROVIDER://KV-URL")
}
options = append(options, nwconfig.OptionKVProvider(kv[0]))
options = append(options, nwconfig.OptionKVProviderURL(kv[1]))
}
if len(dconfig.ClusterOpts) > 0 {
options = append(options, nwconfig.OptionKVOpts(dconfig.ClusterOpts))
}
if daemon.discoveryWatcher != nil {
options = append(options, nwconfig.OptionDiscoveryWatcher(daemon.discoveryWatcher))
}
if dconfig.ClusterAdvertise != "" {
options = append(options, nwconfig.OptionDiscoveryAddress(dconfig.ClusterAdvertise))
}
options = append(options, nwconfig.OptionLabels(dconfig.Labels))
options = append(options, driverOptions(dconfig)...)
if daemon.configStore != nil && daemon.configStore.LiveRestoreEnabled && len(activeSandboxes) != 0 {
options = append(options, nwconfig.OptionActiveSandboxes(activeSandboxes))
}
return options, nil
}
func copyBlkioEntry(entries []*containerd.BlkioStatsEntry) []types.BlkioStatEntry {
out := make([]types.BlkioStatEntry, len(entries))
for i, re := range entries {
out[i] = types.BlkioStatEntry{
Major: re.Major,
Minor: re.Minor,
Op: re.Op,
Value: re.Value,
}
}
return out
}