mirror of
https://github.com/etcd-io/etcd.git
synced 2024-09-27 06:25:44 +00:00
110 lines
2.2 KiB
Go
110 lines
2.2 KiB
Go
/*
|
|
Copyright 2014 CoreOS, Inc.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package proxy
|
|
|
|
import (
|
|
"errors"
|
|
"log"
|
|
"net/url"
|
|
"sync"
|
|
"time"
|
|
)
|
|
|
|
const (
|
|
// amount of time an endpoint will be held in a failed
|
|
// state before being reconsidered for proxied requests
|
|
endpointFailureWait = 5 * time.Second
|
|
)
|
|
|
|
func newDirector(scheme string, addrs []string) (*director, error) {
|
|
if len(addrs) == 0 {
|
|
return nil, errors.New("one or more upstream addresses required")
|
|
}
|
|
|
|
endpoints := make([]*endpoint, len(addrs))
|
|
for i, addr := range addrs {
|
|
u := url.URL{Scheme: scheme, Host: addr}
|
|
endpoints[i] = newEndpoint(u)
|
|
}
|
|
|
|
d := director{ep: endpoints}
|
|
return &d, nil
|
|
}
|
|
|
|
type director struct {
|
|
ep []*endpoint
|
|
}
|
|
|
|
func (d *director) endpoints() []*endpoint {
|
|
filtered := make([]*endpoint, 0)
|
|
for _, ep := range d.ep {
|
|
if ep.Available {
|
|
filtered = append(filtered, ep)
|
|
}
|
|
}
|
|
|
|
return filtered
|
|
}
|
|
|
|
func newEndpoint(u url.URL) *endpoint {
|
|
ep := endpoint{
|
|
URL: u,
|
|
Available: true,
|
|
failFunc: timedUnavailabilityFunc(endpointFailureWait),
|
|
}
|
|
|
|
return &ep
|
|
}
|
|
|
|
type endpoint struct {
|
|
sync.Mutex
|
|
|
|
URL url.URL
|
|
Available bool
|
|
|
|
failFunc func(ep *endpoint)
|
|
}
|
|
|
|
func (ep *endpoint) Failed() {
|
|
ep.Lock()
|
|
if !ep.Available {
|
|
ep.Unlock()
|
|
return
|
|
}
|
|
|
|
ep.Available = false
|
|
ep.Unlock()
|
|
|
|
log.Printf("proxy: marked endpoint %s unavailable", ep.URL.String())
|
|
|
|
if ep.failFunc == nil {
|
|
log.Printf("proxy: no failFunc defined, endpoint %s will be unavailable forever.", ep.URL.String())
|
|
return
|
|
}
|
|
|
|
ep.failFunc(ep)
|
|
}
|
|
|
|
func timedUnavailabilityFunc(wait time.Duration) func(*endpoint) {
|
|
return func(ep *endpoint) {
|
|
time.AfterFunc(wait, func() {
|
|
ep.Available = true
|
|
log.Printf("proxy: marked endpoint %s available", ep.URL.String())
|
|
})
|
|
}
|
|
}
|