package docker import ( "container/list" "fmt" "github.com/dotcloud/docker/auth" "io" "io/ioutil" "log" "os" "os/exec" "path" "sort" "strings" ) type Capabilities struct { MemoryLimit bool SwapLimit bool } type Runtime struct { root string repository string containers *list.List networkManager *NetworkManager graph *Graph repositories *TagStore authConfig *auth.AuthConfig idIndex *TruncIndex capabilities *Capabilities kernelVersion *KernelVersionInfo autoRestart bool volumes *Graph } var sysInitPath string func init() { sysInitPath = SelfPath() } func (runtime *Runtime) List() []*Container { containers := new(History) for e := runtime.containers.Front(); e != nil; e = e.Next() { containers.Add(e.Value.(*Container)) } return *containers } func (runtime *Runtime) getContainerElement(id string) *list.Element { for e := runtime.containers.Front(); e != nil; e = e.Next() { container := e.Value.(*Container) if container.Id == id { return e } } return nil } func (runtime *Runtime) Get(name string) *Container { id, err := runtime.idIndex.Get(name) if err != nil { return nil } e := runtime.getContainerElement(id) if e == nil { return nil } return e.Value.(*Container) } func (runtime *Runtime) Exists(id string) bool { return runtime.Get(id) != nil } func (runtime *Runtime) containerRoot(id string) string { return path.Join(runtime.repository, id) } func (runtime *Runtime) Load(id string) (*Container, error) { container := &Container{root: runtime.containerRoot(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) } if container.State.Running { container.State.Ghost = true } if err := runtime.Register(container); err != nil { return nil, err } return container, nil } // Register makes a container object usable by the runtime as func (runtime *Runtime) Register(container *Container) error { if container.runtime != nil || runtime.Exists(container.Id) { return fmt.Errorf("Container is already loaded") } if err := validateId(container.Id); err != nil { return err } // init the wait lock container.waitLock = make(chan struct{}) // Even if not running, we init the lock (prevents races in start/stop/kill) container.State.initLock() container.runtime = runtime // Attach to stdout and stderr container.stderr = newWriteBroadcaster() container.stdout = newWriteBroadcaster() // Attach to stdin if container.Config.OpenStdin { container.stdin, container.stdinPipe = io.Pipe() } else { container.stdinPipe = NopWriteCloser(ioutil.Discard) // Silently drop stdin } // done runtime.containers.PushBack(container) runtime.idIndex.Add(container.Id) // When we actually restart, Start() do the monitoring. // However, when we simply 'reattach', we have to restart a monitor nomonitor := false // FIXME: if the container is supposed to be running but is not, auto restart it? // if so, then we need to restart monitor and init a new lock // If the container is supposed to be running, make sure of it if container.State.Running { if output, err := exec.Command("lxc-info", "-n", container.Id).CombinedOutput(); err != nil { return err } else { if !strings.Contains(string(output), "RUNNING") { Debugf("Container %s was supposed to be running be is not.", container.Id) if runtime.autoRestart { Debugf("Restarting") container.State.Ghost = false container.State.setStopped(0) if err := container.Start(); err != nil { return err } nomonitor = true } else { Debugf("Marking as stopped") container.State.setStopped(-127) if err := container.ToDisk(); err != nil { return err } } } } } // If the container is not running or just has been flagged not running // then close the wait lock chan (will be reset upon start) if !container.State.Running { close(container.waitLock) } else if !nomonitor { container.allocateNetwork() go container.monitor() } return nil } func (runtime *Runtime) LogToDisk(src *writeBroadcaster, dst string) error { log, err := os.OpenFile(dst, os.O_RDWR|os.O_APPEND|os.O_CREATE, 0600) if err != nil { return err } src.AddWriter(log) return nil } func (runtime *Runtime) Destroy(container *Container) error { element := runtime.getContainerElement(container.Id) if element == nil { return fmt.Errorf("Container %v not found - maybe it was already destroyed?", container.Id) } if err := container.Stop(10); err != nil { return err } if mounted, err := container.Mounted(); err != nil { return err } else if mounted { if err := container.Unmount(); err != nil { return fmt.Errorf("Unable to unmount container %v: %v", container.Id, err) } } // Deregister the container before removing its directory, to avoid race conditions runtime.idIndex.Delete(container.Id) runtime.containers.Remove(element) if err := os.RemoveAll(container.root); err != nil { return fmt.Errorf("Unable to remove filesystem for %v: %v", container.Id, err) } return nil } func (runtime *Runtime) restore() error { dir, err := ioutil.ReadDir(runtime.repository) if err != nil { return err } for _, v := range dir { id := v.Name() container, err := runtime.Load(id) if err != nil { Debugf("Failed to load container %v: %v", id, err) continue } Debugf("Loaded container %v", container.Id) } return nil } func (runtime *Runtime) UpdateCapabilities(quiet bool) { if cgroupMemoryMountpoint, err := FindCgroupMountpoint("memory"); err != nil { if !quiet { log.Printf("WARNING: %s\n", err) } } else { _, err1 := ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.limit_in_bytes")) _, err2 := ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.soft_limit_in_bytes")) runtime.capabilities.MemoryLimit = err1 == nil && err2 == nil if !runtime.capabilities.MemoryLimit && !quiet { log.Printf("WARNING: Your kernel does not support cgroup memory limit.") } _, err = ioutil.ReadFile(path.Join(cgroupMemoryMountpoint, "memory.memsw.limit_in_bytes")) runtime.capabilities.SwapLimit = err == nil if !runtime.capabilities.SwapLimit && !quiet { log.Printf("WARNING: Your kernel does not support cgroup swap limit.") } } } // FIXME: harmonize with NewGraph() func NewRuntime(autoRestart bool) (*Runtime, error) { runtime, err := NewRuntimeFromDirectory("/var/lib/docker", autoRestart) if err != nil { return nil, err } if k, err := GetKernelVersion(); err != nil { log.Printf("WARNING: %s\n", err) } else { runtime.kernelVersion = k if CompareKernelVersion(k, &KernelVersionInfo{Kernel: 3, Major: 8, Minor: 0}) < 0 { log.Printf("WARNING: You are running linux kernel version %s, which might be unstable running docker. Please upgrade your kernel to 3.8.0.", k.String()) } } runtime.UpdateCapabilities(false) return runtime, nil } func NewRuntimeFromDirectory(root string, autoRestart bool) (*Runtime, error) { runtimeRepo := path.Join(root, "containers") if err := os.MkdirAll(runtimeRepo, 0700); err != nil && !os.IsExist(err) { return nil, err } g, err := NewGraph(path.Join(root, "graph")) if err != nil { return nil, err } volumes, err := NewGraph(path.Join(root, "volumes")) if err != nil { return nil, err } repositories, err := NewTagStore(path.Join(root, "repositories"), g) if err != nil { return nil, fmt.Errorf("Couldn't create Tag store: %s", err) } if NetworkBridgeIface == "" { NetworkBridgeIface = DefaultNetworkBridge } netManager, err := newNetworkManager(NetworkBridgeIface) if err != nil { return nil, err } authConfig, err := auth.LoadConfig(root) if err != nil && authConfig == nil { // If the auth file does not exist, keep going return nil, err } runtime := &Runtime{ root: root, repository: runtimeRepo, containers: list.New(), networkManager: netManager, graph: g, repositories: repositories, authConfig: authConfig, idIndex: NewTruncIndex(), capabilities: &Capabilities{}, autoRestart: autoRestart, volumes: volumes, } if err := runtime.restore(); err != nil { return nil, err } return runtime, nil } type History []*Container func (history *History) Len() int { return len(*history) } func (history *History) Less(i, j int) bool { containers := *history return containers[j].When().Before(containers[i].When()) } func (history *History) Swap(i, j int) { containers := *history tmp := containers[i] containers[i] = containers[j] containers[j] = tmp } func (history *History) Add(container *Container) { *history = append(*history, container) sort.Sort(history) }