Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
97 lines (84 sloc) 2.65 KB
package etcdv3
import (
"sync"
"time"
"github.com/go-kit/kit/log"
)
const minHeartBeatTime = 500 * time.Millisecond
// Registrar registers service instance liveness information to etcd.
type Registrar struct {
client Client
service Service
logger log.Logger
quitmtx sync.Mutex
quit chan struct{}
}
// Service holds the instance identifying data you want to publish to etcd. Key
// must be unique, and value is the string returned to subscribers, typically
// called the "instance" string in other parts of package sd.
type Service struct {
Key string // unique key, e.g. "/service/foobar/1.2.3.4:8080"
Value string // returned to subscribers, e.g. "http://1.2.3.4:8080"
TTL *TTLOption
}
// TTLOption allow setting a key with a TTL. This option will be used by a loop
// goroutine which regularly refreshes the lease of the key.
type TTLOption struct {
heartbeat time.Duration // e.g. time.Second * 3
ttl time.Duration // e.g. time.Second * 10
}
// NewTTLOption returns a TTLOption that contains proper TTL settings. Heartbeat
// is used to refresh the lease of the key periodically; its value should be at
// least 500ms. TTL defines the lease of the key; its value should be
// significantly greater than heartbeat.
//
// Good default values might be 3s heartbeat, 10s TTL.
func NewTTLOption(heartbeat, ttl time.Duration) *TTLOption {
if heartbeat <= minHeartBeatTime {
heartbeat = minHeartBeatTime
}
if ttl <= heartbeat {
ttl = 3 * heartbeat
}
return &TTLOption{
heartbeat: heartbeat,
ttl: ttl,
}
}
// NewRegistrar returns a etcd Registrar acting on the provided catalog
// registration (service).
func NewRegistrar(client Client, service Service, logger log.Logger) *Registrar {
return &Registrar{
client: client,
service: service,
logger: log.With(logger, "key", service.Key, "value", service.Value),
}
}
// Register implements the sd.Registrar interface. Call it when you want your
// service to be registered in etcd, typically at startup.
func (r *Registrar) Register() {
if err := r.client.Register(r.service); err != nil {
r.logger.Log("err", err)
return
}
if r.service.TTL != nil {
r.logger.Log("action", "register", "lease", r.client.LeaseID())
} else {
r.logger.Log("action", "register")
}
}
// Deregister implements the sd.Registrar interface. Call it when you want your
// service to be deregistered from etcd, typically just prior to shutdown.
func (r *Registrar) Deregister() {
if err := r.client.Deregister(r.service); err != nil {
r.logger.Log("err", err)
} else {
r.logger.Log("action", "deregister")
}
r.quitmtx.Lock()
defer r.quitmtx.Unlock()
if r.quit != nil {
close(r.quit)
r.quit = nil
}
}
You can’t perform that action at this time.