/
etcd.go
112 lines (96 loc) · 2.14 KB
/
etcd.go
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package etcd
import (
"context"
"encoding/json"
"errors"
"fmt"
"github.com/geniuscirno/go-actor/cluster/registry"
clientv3 "go.etcd.io/etcd/client/v3"
"time"
)
type Option func(*options)
type options struct {
namespace string
ttl time.Duration
}
func defaultOptions() options {
return options{
namespace: "node",
ttl: time.Second * 60,
}
}
func Namespace(ns string) Option {
return func(o *options) {
o.namespace = ns
}
}
func TTL(ttl time.Duration) Option {
return func(o *options) {
o.ttl = ttl
}
}
type Registry struct {
opts options
ctx context.Context
cancel context.CancelFunc
client *clientv3.Client
lease clientv3.Lease
leaseID clientv3.LeaseID
}
func New(client *clientv3.Client, opt ...Option) *Registry {
opts := defaultOptions()
for _, o := range opt {
o(&opts)
}
ctx, cancel := context.WithCancel(context.Background())
return &Registry{client: client, ctx: ctx, cancel: cancel, opts: opts}
}
func (r *Registry) Register(ctx context.Context, node *registry.Node) error {
key := fmt.Sprintf("%s/%s", r.opts.namespace, node.Name)
b, err := json.Marshal(node)
if err != nil {
return err
}
r.lease = clientv3.NewLease(r.client)
grant, err := r.lease.Grant(ctx, int64(r.opts.ttl.Seconds()))
if err != nil {
return err
}
if _, err := r.client.Put(ctx, key, string(b), clientv3.WithLease(grant.ID)); err != nil {
return err
}
r.leaseID = grant.ID
return nil
}
func (r *Registry) Deregister(ctx context.Context, node *registry.Node) error {
defer func() {
r.cancel()
if r.lease != nil {
r.lease.Close()
}
}()
key := fmt.Sprintf("%s/%s", r.opts.namespace, node.Name)
if _, err := r.client.Delete(ctx, key); err != nil {
return err
}
return nil
}
func (r *Registry) KeepAlive(ctx context.Context) error {
keepAliveChan, err := r.lease.KeepAlive(ctx, r.leaseID)
if err != nil {
return err
}
for {
select {
case _, ok := <-keepAliveChan:
if !ok {
return errors.New("keepalive chan closed")
}
case <-r.ctx.Done():
return nil
}
}
}
func (r *Registry) Watch(ctx context.Context) (registry.Watcher, error) {
return newWatcher(ctx, r.opts.namespace, r.client)
}