package docker
import (
"container/list"
"fmt"
"github.com/dotcloud/docker/utils"
"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
idIndex *utils.TruncIndex
capabilities *Capabilities
kernelVersion *utils.KernelVersionInfo
autoRestart bool
volumes *Graph
srv *Server
Dns []string
}
var sysInitPath string
func init() {
sysInitPath = utils.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 <container.ID>
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 = utils.NewWriteBroadcaster()
container.stdout = utils.NewWriteBroadcaster()
// Attach to stdin
if container.Config.OpenStdin {
container.stdin, container.stdinPipe = io.Pipe()
} else {
container.stdinPipe = utils.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 {
output, err := exec.Command("lxc-info", "-n", container.ID).CombinedOutput()
if err != nil {
return err
}
if !strings.Contains(string(output), "RUNNING") {
utils.Debugf("Container %s was supposed to be running be is not.", container.ID)
if runtime.autoRestart {
utils.Debugf("Restarting")
container.State.Ghost = false
container.State.setStopped(0)
if err := container.Start(); err != nil {
return err
}
nomonitor = true
} else {
utils.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 *utils.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 {
if container == nil {
return fmt.Errorf("The given container is <nil>")
}
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(3); 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 {
utils.Debugf("Failed to load container %v: %v", id, err)
continue
}
utils.Debugf("Loaded container %v", container.ID)
}
return nil
}
func (runtime *Runtime) UpdateCapabilities(quiet bool) {
if cgroupMemoryMountpoint, err := utils.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, dns []string) (*Runtime, error) {
runtime, err := NewRuntimeFromDirectory("/var/lib/docker", autoRestart)
if err != nil {
return nil, err
}
runtime.Dns = dns
if k, err := utils.GetKernelVersion(); err != nil {
log.Printf("WARNING: %s\n", err)
} else {
runtime.kernelVersion = k
if utils.CompareKernelVersion(k, &utils.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
}
runtime := &Runtime{
root: root,
repository: runtimeRepo,
containers: list.New(),
networkManager: netManager,
graph: g,
repositories: repositories,
idIndex: utils.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)
}