2015-01-25 06:19:16 +03:00
|
|
|
// Copyright 2015 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.
|
2014-10-18 02:41:22 +04:00
|
|
|
|
2014-09-11 03:38:52 +04:00
|
|
|
package proxy
|
|
|
|
|
|
|
|
import (
|
|
|
|
"log"
|
2015-04-07 22:40:29 +03:00
|
|
|
"math/rand"
|
2014-09-11 03:38:52 +04:00
|
|
|
"net/url"
|
|
|
|
"sync"
|
|
|
|
"time"
|
|
|
|
)
|
|
|
|
|
2015-06-12 21:35:38 +03:00
|
|
|
func newDirector(urlsFunc GetProxyURLs, failureWait time.Duration, refreshInterval time.Duration) *director {
|
2014-10-25 02:26:05 +04:00
|
|
|
d := &director{
|
2015-07-03 15:11:40 +03:00
|
|
|
uf: urlsFunc,
|
|
|
|
failureWait: failureWait,
|
2014-09-11 03:38:52 +04:00
|
|
|
}
|
2014-10-25 02:26:05 +04:00
|
|
|
d.refresh()
|
|
|
|
go func() {
|
|
|
|
for {
|
|
|
|
select {
|
2015-06-12 21:35:38 +03:00
|
|
|
case <-time.After(refreshInterval):
|
2014-10-25 02:26:05 +04:00
|
|
|
d.refresh()
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}()
|
|
|
|
return d
|
2014-09-11 03:38:52 +04:00
|
|
|
}
|
|
|
|
|
|
|
|
type director struct {
|
2014-10-25 02:26:05 +04:00
|
|
|
sync.Mutex
|
2015-06-12 21:35:38 +03:00
|
|
|
ep []*endpoint
|
|
|
|
uf GetProxyURLs
|
|
|
|
failureWait time.Duration
|
|
|
|
refreshInterval time.Duration
|
2014-10-25 02:26:05 +04:00
|
|
|
}
|
|
|
|
|
|
|
|
func (d *director) refresh() {
|
|
|
|
urls := d.uf()
|
|
|
|
d.Lock()
|
|
|
|
defer d.Unlock()
|
|
|
|
var endpoints []*endpoint
|
|
|
|
for _, u := range urls {
|
|
|
|
uu, err := url.Parse(u)
|
|
|
|
if err != nil {
|
2014-10-31 02:48:23 +03:00
|
|
|
log.Printf("proxy: upstream URL invalid: %v", err)
|
2014-10-25 02:26:05 +04:00
|
|
|
continue
|
|
|
|
}
|
2015-06-12 21:35:38 +03:00
|
|
|
endpoints = append(endpoints, newEndpoint(*uu, d.failureWait))
|
2014-10-25 02:26:05 +04:00
|
|
|
}
|
2015-04-07 22:40:29 +03:00
|
|
|
|
|
|
|
// shuffle array to avoid connections being "stuck" to a single endpoint
|
|
|
|
for i := range endpoints {
|
|
|
|
j := rand.Intn(i + 1)
|
|
|
|
endpoints[i], endpoints[j] = endpoints[j], endpoints[i]
|
|
|
|
}
|
|
|
|
|
2014-10-25 02:26:05 +04:00
|
|
|
d.ep = endpoints
|
2014-09-11 03:38:52 +04:00
|
|
|
}
|
|
|
|
|
|
|
|
func (d *director) endpoints() []*endpoint {
|
2014-10-25 02:26:05 +04:00
|
|
|
d.Lock()
|
|
|
|
defer d.Unlock()
|
2014-09-11 03:38:52 +04:00
|
|
|
filtered := make([]*endpoint, 0)
|
|
|
|
for _, ep := range d.ep {
|
|
|
|
if ep.Available {
|
|
|
|
filtered = append(filtered, ep)
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return filtered
|
|
|
|
}
|
|
|
|
|
2015-06-12 21:35:38 +03:00
|
|
|
func newEndpoint(u url.URL, failureWait time.Duration) *endpoint {
|
2014-09-11 03:38:52 +04:00
|
|
|
ep := endpoint{
|
|
|
|
URL: u,
|
|
|
|
Available: true,
|
2015-06-12 21:35:38 +03:00
|
|
|
failFunc: timedUnavailabilityFunc(failureWait),
|
2014-09-11 03:38:52 +04:00
|
|
|
}
|
|
|
|
|
|
|
|
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
|
2015-09-21 11:16:11 +03:00
|
|
|
log.Printf("proxy: marked endpoint %s available, to retest connectivity", ep.URL.String())
|
2014-09-11 03:38:52 +04:00
|
|
|
})
|
|
|
|
}
|
|
|
|
}
|