mirror of https://github.com/docker/docs.git
83 lines
1.8 KiB
Go
83 lines
1.8 KiB
Go
package etcd
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import (
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"fmt"
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"path"
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"strings"
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log "github.com/Sirupsen/logrus"
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"github.com/coreos/go-etcd/etcd"
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"github.com/docker/swarm/discovery"
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)
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type EtcdDiscoveryService struct {
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ttl uint64
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client *etcd.Client
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path string
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}
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func init() {
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discovery.Register("etcd", &EtcdDiscoveryService{})
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}
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func (s *EtcdDiscoveryService) Initialize(uris string, heartbeat int) error {
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var (
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// split here because uris can contain multiples ips
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// like `etcd://192.168.0.1,192.168.0.2,192.168.0.3/path`
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parts = strings.SplitN(uris, "/", 2)
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ips = strings.Split(parts[0], ",")
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entries []string
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)
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if len(parts) != 2 {
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return fmt.Errorf("invalid format %q, missing <path>", uris)
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}
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for _, ip := range ips {
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entries = append(entries, "http://"+ip)
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}
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s.client = etcd.NewClient(entries)
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s.ttl = uint64(heartbeat * 3 / 2)
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s.path = "/" + parts[1] + "/"
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if _, err := s.client.CreateDir(s.path, s.ttl); err != nil {
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if etcdError, ok := err.(*etcd.EtcdError); ok {
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if etcdError.ErrorCode != 105 { // skip key already exists
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return err
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}
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} else {
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return err
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}
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}
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return nil
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}
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func (s *EtcdDiscoveryService) Fetch() ([]*discovery.Entry, error) {
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resp, err := s.client.Get(s.path, true, true)
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if err != nil {
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return nil, err
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}
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addrs := []string{}
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for _, n := range resp.Node.Nodes {
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addrs = append(addrs, n.Value)
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}
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return discovery.CreateEntries(addrs)
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}
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func (s *EtcdDiscoveryService) Watch(callback discovery.WatchCallback) {
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watchChan := make(chan *etcd.Response)
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go s.client.Watch(s.path, 0, true, watchChan, nil)
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for _ = range watchChan {
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log.WithField("name", "etcd").Debug("Discovery watch triggered")
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entries, err := s.Fetch()
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if err == nil {
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callback(entries)
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}
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}
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}
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func (s *EtcdDiscoveryService) Register(addr string) error {
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_, err := s.client.Set(path.Join(s.path, addr), addr, s.ttl)
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return err
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}
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