package daemon import ( "errors" "fmt" "io" "io/ioutil" "os" "path/filepath" "regexp" "runtime" "strings" "sync" "time" "github.com/Sirupsen/logrus" "github.com/docker/docker/api" "github.com/docker/docker/daemon/events" "github.com/docker/docker/daemon/execdriver" "github.com/docker/docker/daemon/execdriver/execdrivers" "github.com/docker/docker/daemon/graphdriver" _ "github.com/docker/docker/daemon/graphdriver/vfs" "github.com/docker/docker/daemon/logger" "github.com/docker/docker/daemon/network" "github.com/docker/docker/graph" "github.com/docker/docker/pkg/broadcastwriter" "github.com/docker/docker/pkg/fileutils" "github.com/docker/docker/pkg/graphdb" "github.com/docker/docker/pkg/ioutils" "github.com/docker/docker/pkg/namesgenerator" "github.com/docker/docker/pkg/stringid" "github.com/docker/docker/pkg/sysinfo" "github.com/docker/docker/pkg/system" "github.com/docker/docker/pkg/truncindex" "github.com/docker/docker/registry" "github.com/docker/docker/runconfig" "github.com/docker/docker/trust" "github.com/docker/libcontainer/netlink" "github.com/docker/libnetwork" ) var ( validContainerNameChars = `[a-zA-Z0-9][a-zA-Z0-9_.-]` validContainerNamePattern = regexp.MustCompile(`^/?` + validContainerNameChars + `+$`) ErrSystemNotSupported = errors.New("The Docker daemon is not supported on this platform.") ) type contStore struct { s map[string]*Container sync.Mutex } func (c *contStore) Add(id string, cont *Container) { c.Lock() c.s[id] = cont c.Unlock() } func (c *contStore) Get(id string) *Container { c.Lock() res := c.s[id] c.Unlock() return res } func (c *contStore) Delete(id string) { c.Lock() delete(c.s, id) c.Unlock() } func (c *contStore) List() []*Container { containers := new(History) c.Lock() for _, cont := range c.s { containers.Add(cont) } c.Unlock() containers.Sort() return *containers } type Daemon struct { ID string repository string sysInitPath string containers *contStore execCommands *execStore graph *graph.Graph repositories *graph.TagStore idIndex *truncindex.TruncIndex sysInfo *sysinfo.SysInfo config *Config containerGraph *graphdb.Database driver graphdriver.Driver execDriver execdriver.Driver statsCollector *statsCollector defaultLogConfig runconfig.LogConfig RegistryService *registry.Service EventsService *events.Events netController libnetwork.NetworkController root string } // Get looks for a container using the provided information, which could be // one of the following inputs from the caller: // - A full container ID, which will exact match a container in daemon's list // - A container name, which will only exact match via the GetByName() function // - A partial container ID prefix (e.g. short ID) of any length that is // unique enough to only return a single container object // If none of these searches succeed, an error is returned func (daemon *Daemon) Get(prefixOrName string) (*Container, error) { if containerByID := daemon.containers.Get(prefixOrName); containerByID != nil { // prefix is an exact match to a full container ID return containerByID, nil } // GetByName will match only an exact name provided; we ignore errors if containerByName, _ := daemon.GetByName(prefixOrName); containerByName != nil { // prefix is an exact match to a full container Name return containerByName, nil } containerId, indexError := daemon.idIndex.Get(prefixOrName) if indexError != nil { return nil, indexError } return daemon.containers.Get(containerId), nil } // Exists returns a true if a container of the specified ID or name exists, // false otherwise. func (daemon *Daemon) Exists(id string) bool { c, _ := daemon.Get(id) return c != nil } func (daemon *Daemon) containerRoot(id string) string { return filepath.Join(daemon.repository, id) } // Load reads the contents of a container from disk // This is typically done at startup. func (daemon *Daemon) load(id string) (*Container, error) { container := &Container{ CommonContainer: daemon.newBaseContainer(id), } if err := container.FromDisk(); err != nil { return nil, err } if container.ID != id { return container, fmt.Errorf("Container %s is stored at %s", container.ID, id) } return container, nil } // Register makes a container object usable by the daemon as // This is a wrapper for register func (daemon *Daemon) Register(container *Container) error { return daemon.register(container, true) } // register makes a container object usable by the daemon as func (daemon *Daemon) register(container *Container, updateSuffixarray bool) error { if container.daemon != nil || daemon.Exists(container.ID) { return fmt.Errorf("Container is already loaded") } if err := validateID(container.ID); err != nil { return err } if err := daemon.ensureName(container); err != nil { return err } container.daemon = daemon // Attach to stdout and stderr container.stderr = broadcastwriter.New() container.stdout = broadcastwriter.New() // Attach to stdin if container.Config.OpenStdin { container.stdin, container.stdinPipe = io.Pipe() } else { container.stdinPipe = ioutils.NopWriteCloser(ioutil.Discard) // Silently drop stdin } // done daemon.containers.Add(container.ID, container) // don't update the Suffixarray if we're starting up // we'll waste time if we update it for every container daemon.idIndex.Add(container.ID) if err := daemon.verifyVolumesInfo(container); err != nil { return err } if err := container.prepareMountPoints(); err != nil { return err } if container.IsRunning() { logrus.Debugf("killing old running container %s", container.ID) // Set exit code to 128 + SIGKILL (9) to properly represent unsuccessful exit container.SetStopped(&execdriver.ExitStatus{ExitCode: 137}) // use the current driver and ensure that the container is dead x.x cmd := &execdriver.Command{ ID: container.ID, } daemon.execDriver.Terminate(cmd) if err := container.Unmount(); err != nil { logrus.Debugf("unmount error %s", err) } if err := container.ToDisk(); err != nil { logrus.Errorf("Error saving stopped state to disk: %v", err) } } return nil } func (daemon *Daemon) ensureName(container *Container) error { if container.Name == "" { name, err := daemon.generateNewName(container.ID) if err != nil { return err } container.Name = name if err := container.ToDisk(); err != nil { logrus.Errorf("Error saving container name to disk: %v", err) } } return nil } func (daemon *Daemon) restore() error { type cr struct { container *Container registered bool } var ( debug = (os.Getenv("DEBUG") != "" || os.Getenv("TEST") != "") currentDriver = daemon.driver.String() containers = make(map[string]*cr) ) if !debug { logrus.Info("Loading containers: start.") } dir, err := ioutil.ReadDir(daemon.repository) if err != nil { return err } for _, v := range dir { id := v.Name() container, err := daemon.load(id) if !debug && logrus.GetLevel() == logrus.InfoLevel { fmt.Print(".") } if err != nil { logrus.Errorf("Failed to load container %v: %v", id, err) 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 { logrus.Debugf("Loaded container %v", container.ID) containers[container.ID] = &cr{container: container} } else { logrus.Debugf("Cannot load container %s because it was created with another graph driver.", container.ID) } } if entities := daemon.containerGraph.List("/", -1); entities != nil { for _, p := range entities.Paths() { if !debug && logrus.GetLevel() == logrus.InfoLevel { fmt.Print(".") } e := entities[p] if c, ok := containers[e.ID()]; ok { c.registered = true } } } group := sync.WaitGroup{} for _, c := range containers { group.Add(1) go func(container *Container, registered bool) { defer group.Done() if !registered { // Try to set the default name for a container if it exists prior to links container.Name, err = daemon.generateNewName(container.ID) if err != nil { logrus.Debugf("Setting default id - %s", err) } } if err := daemon.register(container, false); err != nil { logrus.Debugf("Failed to register container %s: %s", container.ID, err) } // check the restart policy on the containers and restart any container with // the restart policy of "always" if daemon.config.AutoRestart && container.shouldRestart() { logrus.Debugf("Starting container %s", container.ID) if err := container.Start(); err != nil { logrus.Debugf("Failed to start container %s: %s", container.ID, err) } } }(c.container, c.registered) } group.Wait() if !debug { if logrus.GetLevel() == logrus.InfoLevel { fmt.Println() } logrus.Info("Loading containers: done.") } return nil } func (daemon *Daemon) mergeAndVerifyConfig(config *runconfig.Config, img *graph.Image) error { if img != nil && img.Config != nil { if err := runconfig.Merge(config, img.Config); err != nil { return err } } if config.Entrypoint.Len() == 0 && config.Cmd.Len() == 0 { return fmt.Errorf("No command specified") } return nil } func (daemon *Daemon) generateIdAndName(name string) (string, string, error) { var ( err error id = stringid.GenerateRandomID() ) if name == "" { if name, err = daemon.generateNewName(id); err != nil { return "", "", err } return id, name, nil } if name, err = daemon.reserveName(id, name); err != nil { return "", "", err } return id, name, nil } func (daemon *Daemon) reserveName(id, name string) (string, error) { if !validContainerNamePattern.MatchString(name) { return "", fmt.Errorf("Invalid container name (%s), only %s are allowed", name, validContainerNameChars) } if name[0] != '/' { name = "/" + name } if _, err := daemon.containerGraph.Set(name, id); err != nil { if !graphdb.IsNonUniqueNameError(err) { return "", err } conflictingContainer, err := daemon.GetByName(name) if err != nil { if strings.Contains(err.Error(), "Could not find entity") { return "", err } // Remove name and continue starting the container if err := daemon.containerGraph.Delete(name); err != nil { return "", err } } else { nameAsKnownByUser := strings.TrimPrefix(name, "/") return "", fmt.Errorf( "Conflict. The name %q is already in use by container %s. You have to delete (or rename) that container to be able to reuse that name.", nameAsKnownByUser, stringid.TruncateID(conflictingContainer.ID)) } } return name, nil } func (daemon *Daemon) generateNewName(id string) (string, error) { var name string for i := 0; i < 6; i++ { name = namesgenerator.GetRandomName(i) if name[0] != '/' { name = "/" + name } if _, err := daemon.containerGraph.Set(name, id); err != nil { if !graphdb.IsNonUniqueNameError(err) { return "", err } continue } return name, nil } name = "/" + stringid.TruncateID(id) if _, err := daemon.containerGraph.Set(name, id); err != nil { return "", err } return name, nil } func (daemon *Daemon) generateHostname(id string, config *runconfig.Config) { // Generate default hostname // FIXME: the lxc template no longer needs to set a default hostname if config.Hostname == "" { config.Hostname = id[:12] } } func (daemon *Daemon) getEntrypointAndArgs(configEntrypoint *runconfig.Entrypoint, configCmd *runconfig.Command) (string, []string) { var ( entrypoint string args []string ) cmdSlice := configCmd.Slice() if configEntrypoint.Len() != 0 { eSlice := configEntrypoint.Slice() entrypoint = eSlice[0] args = append(eSlice[1:], cmdSlice...) } else { entrypoint = cmdSlice[0] args = cmdSlice[1:] } return entrypoint, args } func (daemon *Daemon) newContainer(name string, config *runconfig.Config, imgID string) (*Container, error) { var ( id string err error ) id, name, err = daemon.generateIdAndName(name) if err != nil { return nil, err } daemon.generateHostname(id, config) entrypoint, args := daemon.getEntrypointAndArgs(config.Entrypoint, config.Cmd) base := daemon.newBaseContainer(id) base.Created = time.Now().UTC() base.Path = entrypoint base.Args = args //FIXME: de-duplicate from config base.Config = config base.hostConfig = &runconfig.HostConfig{} base.ImageID = imgID base.NetworkSettings = &network.Settings{} base.Name = name base.Driver = daemon.driver.String() base.ExecDriver = daemon.execDriver.Name() container := &Container{ CommonContainer: base, } return container, err } func GetFullContainerName(name string) (string, error) { if name == "" { return "", fmt.Errorf("Container name cannot be empty") } if name[0] != '/' { name = "/" + name } return name, nil } func (daemon *Daemon) GetByName(name string) (*Container, error) { fullName, err := GetFullContainerName(name) if err != nil { return nil, err } entity := daemon.containerGraph.Get(fullName) if entity == nil { return nil, fmt.Errorf("Could not find entity for %s", name) } e := daemon.containers.Get(entity.ID()) if e == nil { return nil, fmt.Errorf("Could not find container for entity id %s", entity.ID()) } return e, nil } func (daemon *Daemon) Children(name string) (map[string]*Container, error) { name, err := GetFullContainerName(name) if err != nil { return nil, err } children := make(map[string]*Container) err = daemon.containerGraph.Walk(name, func(p string, e *graphdb.Entity) error { c, err := daemon.Get(e.ID()) if err != nil { return err } children[p] = c return nil }, 0) if err != nil { return nil, err } return children, nil } func (daemon *Daemon) Parents(name string) ([]string, error) { name, err := GetFullContainerName(name) if err != nil { return nil, err } return daemon.containerGraph.Parents(name) } func (daemon *Daemon) RegisterLink(parent, child *Container, alias string) error { fullName := filepath.Join(parent.Name, alias) if !daemon.containerGraph.Exists(fullName) { _, err := daemon.containerGraph.Set(fullName, child.ID) return err } return nil } func NewDaemon(config *Config, registryService *registry.Service) (daemon *Daemon, err error) { setDefaultMtu(config) // Ensure we have compatible configuration options if err := checkConfigOptions(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 runtime.GOOS != "linux" && runtime.GOOS != "windows" { 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() // 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) } } config.Root = realRoot // Create the root directory if it doesn't exists if err := system.MkdirAll(config.Root, 0700); err != nil && !os.IsExist(err) { return nil, err } // set up the tmpDir to use a canonical path tmp, err := tempDir(config.Root) 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) // Set the default driver graphdriver.DefaultDriver = config.GraphDriver // Load storage driver driver, err := graphdriver.New(config.Root, config.GraphOptions) if err != nil { return nil, fmt.Errorf("error initializing graphdriver: %v", err) } logrus.Debugf("Using graph driver %s", driver) d := &Daemon{} d.driver = driver // Ensure the graph driver is shutdown at a later point defer func() { if err != nil { if err := d.Shutdown(); err != nil { logrus.Error(err) } } }() // Verify logging driver type if config.LogConfig.Type != "none" { if _, err := logger.GetLogDriver(config.LogConfig.Type); err != nil { return nil, fmt.Errorf("error finding the logging driver: %v", err) } } logrus.Debugf("Using default logging driver %s", config.LogConfig.Type) // Configure and validate the kernels security support if err := configureKernelSecuritySupport(config, d.driver.String()); err != nil { return nil, err } daemonRepo := filepath.Join(config.Root, "containers") if err := system.MkdirAll(daemonRepo, 0700); err != nil && !os.IsExist(err) { return nil, err } // Migrate the container if it is aufs and aufs is enabled if err := migrateIfDownlevel(d.driver, config.Root); err != nil { return nil, err } logrus.Debug("Creating images graph") g, err := graph.NewGraph(filepath.Join(config.Root, "graph"), d.driver) if err != nil { return nil, err } // Configure the volumes driver if err := configureVolumes(config); err != nil { return nil, err } trustKey, err := api.LoadOrCreateTrustKey(config.TrustKeyPath) if err != nil { return nil, err } trustDir := filepath.Join(config.Root, "trust") if err := system.MkdirAll(trustDir, 0700); err != nil && !os.IsExist(err) { return nil, err } trustService, err := trust.NewTrustStore(trustDir) if err != nil { return nil, fmt.Errorf("could not create trust store: %s", err) } eventsService := events.New() logrus.Debug("Creating repository list") tagCfg := &graph.TagStoreConfig{ Graph: g, Key: trustKey, Registry: registryService, Events: eventsService, Trust: trustService, } repositories, err := graph.NewTagStore(filepath.Join(config.Root, "repositories-"+d.driver.String()), tagCfg) if err != nil { return nil, fmt.Errorf("Couldn't create Tag store: %s", err) } d.netController, err = initNetworkController(config) if err != nil { return nil, fmt.Errorf("Error initializing network controller: %v", err) } graphdbPath := filepath.Join(config.Root, "linkgraph.db") graph, err := graphdb.NewSqliteConn(graphdbPath) if err != nil { return nil, err } d.containerGraph = graph var sysInitPath string if config.ExecDriver == "lxc" { initPath, err := configureSysInit(config) if err != nil { return nil, err } sysInitPath = initPath } sysInfo := sysinfo.New(false) // Check if Devices cgroup is mounted, it is hard requirement for container security, // on Linux/FreeBSD. if runtime.GOOS != "windows" && !sysInfo.CgroupDevicesEnabled { return nil, fmt.Errorf("Devices cgroup isn't mounted") } ed, err := execdrivers.NewDriver(config.ExecDriver, config.ExecOptions, config.ExecRoot, config.Root, sysInitPath, sysInfo) if err != nil { return nil, err } d.ID = trustKey.PublicKey().KeyID() d.repository = daemonRepo d.containers = &contStore{s: make(map[string]*Container)} d.execCommands = newExecStore() d.graph = g d.repositories = repositories d.idIndex = truncindex.NewTruncIndex([]string{}) d.sysInfo = sysInfo d.config = config d.sysInitPath = sysInitPath d.execDriver = ed d.statsCollector = newStatsCollector(1 * time.Second) d.defaultLogConfig = config.LogConfig d.RegistryService = registryService d.EventsService = eventsService d.root = config.Root go d.execCommandGC() if err := d.restore(); err != nil { return nil, err } return d, nil } func (daemon *Daemon) Shutdown() error { if daemon.containers != nil { group := sync.WaitGroup{} logrus.Debug("starting clean shutdown of all containers...") for _, container := range daemon.List() { c := container if c.IsRunning() { logrus.Debugf("stopping %s", c.ID) group.Add(1) go func() { defer group.Done() // If container failed to exit in 10 seconds of SIGTERM, then using the force if err := c.Stop(10); err != nil { logrus.Errorf("Stop container %s with error: %v", c.ID, err) } c.WaitStop(-1 * time.Second) logrus.Debugf("container stopped %s", c.ID) }() } } group.Wait() // trigger libnetwork GC only if it's initialized if daemon.netController != nil { daemon.netController.GC() } } if daemon.containerGraph != nil { if err := daemon.containerGraph.Close(); err != nil { logrus.Errorf("Error during container graph.Close(): %v", err) } } if daemon.driver != nil { if err := daemon.driver.Cleanup(); err != nil { logrus.Errorf("Error during graph storage driver.Cleanup(): %v", err) } } return nil } func (daemon *Daemon) Mount(container *Container) error { dir, err := daemon.driver.Get(container.ID, container.GetMountLabel()) if err != nil { return fmt.Errorf("Error getting container %s from driver %s: %s", container.ID, daemon.driver, err) } 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.driver.Put(container.ID) return fmt.Errorf("Error: driver %s is returning inconsistent paths for container %s ('%s' then '%s')", daemon.driver, container.ID, container.basefs, dir) } } container.basefs = dir return nil } func (daemon *Daemon) Unmount(container *Container) error { daemon.driver.Put(container.ID) return nil } func (daemon *Daemon) Run(c *Container, pipes *execdriver.Pipes, startCallback execdriver.StartCallback) (execdriver.ExitStatus, error) { return daemon.execDriver.Run(c.command, pipes, startCallback) } func (daemon *Daemon) Kill(c *Container, sig int) error { return daemon.execDriver.Kill(c.command, sig) } func (daemon *Daemon) Stats(c *Container) (*execdriver.ResourceStats, error) { return daemon.execDriver.Stats(c.ID) } func (daemon *Daemon) SubscribeToContainerStats(name string) (chan interface{}, error) { c, err := daemon.Get(name) if err != nil { return nil, err } ch := daemon.statsCollector.collect(c) return ch, nil } func (daemon *Daemon) UnsubscribeToContainerStats(name string, ch chan interface{}) error { c, err := daemon.Get(name) if err != nil { return err } daemon.statsCollector.unsubscribe(c, ch) return nil } // FIXME: this is a convenience function for integration tests // which need direct access to daemon.graph. // Once the tests switch to using engine and jobs, this method // can go away. func (daemon *Daemon) Graph() *graph.Graph { return daemon.graph } func (daemon *Daemon) Repositories() *graph.TagStore { return daemon.repositories } func (daemon *Daemon) Config() *Config { return daemon.config } func (daemon *Daemon) SystemConfig() *sysinfo.SysInfo { return daemon.sysInfo } func (daemon *Daemon) SystemInitPath() string { return daemon.sysInitPath } func (daemon *Daemon) GraphDriver() graphdriver.Driver { return daemon.driver } func (daemon *Daemon) ExecutionDriver() execdriver.Driver { return daemon.execDriver } func (daemon *Daemon) ContainerGraph() *graphdb.Database { return daemon.containerGraph } func (daemon *Daemon) ImageGetCached(imgID string, config *runconfig.Config) (*graph.Image, error) { // Retrieve all images images, err := daemon.Graph().Map() if err != nil { return nil, err } // Store the tree in a map of map (map[parentId][childId]) imageMap := make(map[string]map[string]struct{}) for _, img := range images { if _, exists := imageMap[img.Parent]; !exists { imageMap[img.Parent] = make(map[string]struct{}) } imageMap[img.Parent][img.ID] = struct{}{} } // Loop on the children of the given image and check the config var match *graph.Image for elem := range imageMap[imgID] { img, ok := images[elem] if !ok { return nil, fmt.Errorf("unable to find image %q", elem) } if runconfig.Compare(&img.ContainerConfig, config) { if match == nil || match.Created.Before(img.Created) { match = img } } } return match, nil } // tempDir returns the default directory to use for temporary files. func tempDir(rootDir string) (string, error) { var tmpDir string if tmpDir = os.Getenv("DOCKER_TMPDIR"); tmpDir == "" { tmpDir = filepath.Join(rootDir, "tmp") } return tmpDir, system.MkdirAll(tmpDir, 0700) } func (daemon *Daemon) setHostConfig(container *Container, hostConfig *runconfig.HostConfig) error { container.Lock() if err := parseSecurityOpt(container, hostConfig); err != nil { container.Unlock() return err } container.Unlock() // Do not lock while creating volumes since this could be calling out to external plugins // Don't want to block other actions, like `docker ps` because we're waiting on an external plugin if err := daemon.registerMountPoints(container, hostConfig); err != nil { return err } container.Lock() defer container.Unlock() // Register any links from the host config before starting the container if err := daemon.RegisterLinks(container, hostConfig); err != nil { return err } container.hostConfig = hostConfig container.toDisk() return nil } func (daemon *Daemon) newBaseContainer(id string) CommonContainer { return CommonContainer{ ID: id, State: NewState(), MountPoints: make(map[string]*mountPoint), Volumes: make(map[string]string), VolumesRW: make(map[string]bool), execCommands: newExecStore(), root: daemon.containerRoot(id), } } func setDefaultMtu(config *Config) { // do nothing if the config does not have the default 0 value. if config.Mtu != 0 { return } config.Mtu = defaultNetworkMtu if routeMtu, err := getDefaultRouteMtu(); err == nil { config.Mtu = routeMtu } } var errNoDefaultRoute = errors.New("no default route was found") // getDefaultRouteMtu returns the MTU for the default route's interface. func getDefaultRouteMtu() (int, error) { routes, err := netlink.NetworkGetRoutes() if err != nil { return 0, err } for _, r := range routes { if r.Default { return r.Iface.MTU, nil } } return 0, errNoDefaultRoute }