docs/cluster/swarm/cluster.go

438 lines
10 KiB
Go

package swarm
import (
"errors"
"fmt"
"io"
"sort"
"strings"
"sync"
log "github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/units"
"github.com/docker/swarm/cluster"
"github.com/docker/swarm/discovery"
"github.com/docker/swarm/scheduler"
"github.com/docker/swarm/scheduler/node"
"github.com/docker/swarm/state"
"github.com/samalba/dockerclient"
)
// Cluster is exported
type Cluster struct {
sync.RWMutex
eventHandler cluster.EventHandler
engines map[string]*cluster.Engine
scheduler *scheduler.Scheduler
options *cluster.Options
store *state.Store
}
// NewCluster is exported
func NewCluster(scheduler *scheduler.Scheduler, store *state.Store, options *cluster.Options) cluster.Cluster {
log.WithFields(log.Fields{"name": "swarm"}).Debug("Initializing cluster")
cluster := &Cluster{
engines: make(map[string]*cluster.Engine),
scheduler: scheduler,
options: options,
store: store,
}
// get the list of entries from the discovery service
go func() {
d, err := discovery.New(options.Discovery, options.Heartbeat)
if err != nil {
log.Fatal(err)
}
entries, err := d.Fetch()
if err != nil {
log.Fatal(err)
}
cluster.newEntries(entries)
go d.Watch(cluster.newEntries)
}()
return cluster
}
// Handle callbacks for the events
func (c *Cluster) Handle(e *cluster.Event) error {
if c.eventHandler == nil {
return nil
}
if err := c.eventHandler.Handle(e); err != nil {
log.Error(err)
}
return nil
}
// RegisterEventHandler registers an event handler.
func (c *Cluster) RegisterEventHandler(h cluster.EventHandler) error {
if c.eventHandler != nil {
return errors.New("event handler already set")
}
c.eventHandler = h
return nil
}
// CreateContainer aka schedule a brand new container into the cluster.
func (c *Cluster) CreateContainer(config *cluster.ContainerConfig, name string) (*cluster.Container, error) {
c.scheduler.Lock()
defer c.scheduler.Unlock()
// check new name whether avaliable
if cID := c.getIDFromName(name); cID != "" {
return nil, fmt.Errorf("Conflict, The name %s is already assigned to %s. You have to delete (or rename) that container to be able to assign %s to a container again.", name, cID, name)
}
n, err := c.scheduler.SelectNodeForContainer(c.listNodes(), config)
if err != nil {
return nil, err
}
if nn, ok := c.engines[n.ID]; ok {
container, err := nn.Create(config, name, true)
if err != nil {
return nil, err
}
st := &state.RequestedState{
ID: container.Id,
Name: name,
Config: config,
}
return container, c.store.Add(container.Id, st)
}
return nil, nil
}
// RemoveContainer aka Remove a container from the cluster. Containers should
// always be destroyed through the scheduler to guarantee atomicity.
func (c *Cluster) RemoveContainer(container *cluster.Container, force bool) error {
c.scheduler.Lock()
defer c.scheduler.Unlock()
if err := container.Engine.Destroy(container, force); err != nil {
return err
}
if err := c.store.Remove(container.Id); err != nil {
if err == state.ErrNotFound {
log.Debugf("Container %s not found in the store", container.Id)
return nil
}
return err
}
return nil
}
// Entries are Docker Engines
func (c *Cluster) newEntries(entries []*discovery.Entry) {
for _, entry := range entries {
go func(m *discovery.Entry) {
if !c.hasEngine(m.String()) {
engine := cluster.NewEngine(m.String(), c.options.OvercommitRatio)
if err := engine.Connect(c.options.TLSConfig); err != nil {
log.Error(err)
return
}
c.Lock()
if old, exists := c.engines[engine.ID]; exists {
c.Unlock()
if old.Addr != engine.Addr {
log.Errorf("ID duplicated. %s shared by %s and %s", engine.ID, old.Addr, engine.Addr)
} else {
log.Debugf("node %q (name: %q) with address %q is already registered", engine.ID, engine.Name, engine.Addr)
}
return
}
c.engines[engine.ID] = engine
if err := engine.RegisterEventHandler(c); err != nil {
log.Error(err)
c.Unlock()
return
}
c.Unlock()
}
}(entry)
}
}
func (c *Cluster) hasEngine(addr string) bool {
c.RLock()
defer c.RUnlock()
for _, engine := range c.engines {
if engine.Addr == addr {
return true
}
}
return false
}
// Images returns all the images in the cluster.
func (c *Cluster) Images() []*cluster.Image {
c.RLock()
defer c.RUnlock()
out := []*cluster.Image{}
for _, n := range c.engines {
out = append(out, n.Images()...)
}
return out
}
// Image returns an image with IDOrName in the cluster
func (c *Cluster) Image(IDOrName string) *cluster.Image {
// Abort immediately if the name is empty.
if len(IDOrName) == 0 {
return nil
}
c.RLock()
defer c.RUnlock()
for _, n := range c.engines {
if image := n.Image(IDOrName); image != nil {
return image
}
}
return nil
}
// RemoveImage removes an image from the cluster
func (c *Cluster) RemoveImage(image *cluster.Image) ([]*dockerclient.ImageDelete, error) {
c.Lock()
defer c.Unlock()
return image.Engine.RemoveImage(image)
}
// Pull is exported
func (c *Cluster) Pull(name string, authConfig *dockerclient.AuthConfig, callback func(what, status string)) {
var wg sync.WaitGroup
c.RLock()
for _, n := range c.engines {
wg.Add(1)
go func(nn *cluster.Engine) {
defer wg.Done()
if callback != nil {
callback(nn.Name, "")
}
err := nn.Pull(name, authConfig)
if callback != nil {
if err != nil {
callback(nn.Name, err.Error())
} else {
callback(nn.Name, "downloaded")
}
}
}(n)
}
c.RUnlock()
wg.Wait()
}
// Load image
func (c *Cluster) Load(imageReader io.Reader, callback func(what, status string)) {
var wg sync.WaitGroup
c.RLock()
pipeWriters := []*io.PipeWriter{}
pipeReaders := []*io.PipeReader{}
for _, n := range c.engines {
wg.Add(1)
pipeReader, pipeWriter := io.Pipe()
pipeReaders = append(pipeReaders, pipeReader)
pipeWriters = append(pipeWriters, pipeWriter)
go func(reader *io.PipeReader, nn *cluster.Engine) {
defer wg.Done()
defer reader.Close()
// call engine load image
err := nn.Load(reader)
if callback != nil {
if err != nil {
callback(nn.Name, err.Error())
}
}
}(pipeReader, n)
}
// create multi-writer
listWriter := []io.Writer{}
for _, pipeW := range pipeWriters {
listWriter = append(listWriter, pipeW)
}
mutiWriter := io.MultiWriter(listWriter...)
// copy image-reader to muti-writer
_, err := io.Copy(mutiWriter, imageReader)
if err != nil {
log.Error(err)
}
// close pipe writers
for _, pipeW := range pipeWriters {
pipeW.Close()
}
c.RUnlock()
wg.Wait()
}
// Containers returns all the containers in the cluster.
func (c *Cluster) Containers() []*cluster.Container {
c.RLock()
defer c.RUnlock()
out := []*cluster.Container{}
for _, n := range c.engines {
out = append(out, n.Containers()...)
}
return out
}
func (c *Cluster) getIDFromName(name string) string {
// Abort immediately if the name is empty.
if len(name) == 0 {
return ""
}
c.RLock()
defer c.RUnlock()
for _, n := range c.engines {
for _, c := range n.Containers() {
for _, cname := range c.Names {
if cname == name || cname == "/"+name {
return c.Id
}
}
}
}
return ""
}
// Container returns the container with IDOrName in the cluster
func (c *Cluster) Container(IDOrName string) *cluster.Container {
// Abort immediately if the name is empty.
if len(IDOrName) == 0 {
return nil
}
c.RLock()
defer c.RUnlock()
for _, n := range c.engines {
if container := n.Container(IDOrName); container != nil {
return container
}
}
return nil
}
// listNodes returns all the engines in the cluster.
func (c *Cluster) listNodes() []*node.Node {
c.RLock()
defer c.RUnlock()
out := make([]*node.Node, 0, len(c.engines))
for _, n := range c.engines {
out = append(out, node.NewNode(n))
}
return out
}
// listEngines returns all the engines in the cluster.
func (c *Cluster) listEngines() []*cluster.Engine {
c.RLock()
defer c.RUnlock()
out := make([]*cluster.Engine, 0, len(c.engines))
for _, n := range c.engines {
out = append(out, n)
}
return out
}
// Info is exported
func (c *Cluster) Info() [][2]string {
info := [][2]string{
{"\bStrategy", c.scheduler.Strategy()},
{"\bFilters", c.scheduler.Filters()},
{"\bNodes", fmt.Sprintf("%d", len(c.engines))},
}
engines := c.listEngines()
sort.Sort(cluster.EngineSorter(engines))
for _, engine := range engines {
info = append(info, [2]string{engine.Name, engine.Addr})
info = append(info, [2]string{" └ Containers", fmt.Sprintf("%d", len(engine.Containers()))})
info = append(info, [2]string{" └ Reserved CPUs", fmt.Sprintf("%d / %d", engine.UsedCpus(), engine.TotalCpus())})
info = append(info, [2]string{" └ Reserved Memory", fmt.Sprintf("%s / %s", units.BytesSize(float64(engine.UsedMemory())), units.BytesSize(float64(engine.TotalMemory())))})
labels := make([]string, 0, len(engine.Labels))
for k, v := range engine.Labels {
labels = append(labels, k+"="+v)
}
sort.Strings(labels)
info = append(info, [2]string{" └ Labels", fmt.Sprintf("%s", strings.Join(labels, ", "))})
}
return info
}
// RANDOMENGINE returns a random engine.
func (c *Cluster) RANDOMENGINE() (*cluster.Engine, error) {
n, err := c.scheduler.SelectNodeForContainer(c.listNodes(), &cluster.ContainerConfig{})
if err != nil {
return nil, err
}
if n != nil {
return c.engines[n.ID], nil
}
return nil, nil
}
// RenameContainer rename a container
func (c *Cluster) RenameContainer(container *cluster.Container, newName string) error {
c.RLock()
defer c.RUnlock()
// check new name whether avaliable
if cID := c.getIDFromName(newName); cID != "" {
return fmt.Errorf("Conflict, The name %s is already assigned to %s. You have to delete (or rename) that container to be able to assign %s to a container again.", newName, cID, newName)
}
// call engine rename
err := container.Engine.RenameContainer(container, newName)
if err != nil {
return err
}
// update container name in store
st, err := c.store.Get(container.Id)
if err != nil {
return err
}
st.Name = newName
return c.store.Replace(container.Id, st)
}