Files
flux/server/proxy.go

143 lines
3.2 KiB
Go

package server
import (
"context"
"fmt"
"log"
"net/http"
"net/http/httputil"
"net/url"
"os"
"sync"
"sync/atomic"
"time"
)
var ReverseProxy *Proxy
type Proxy struct {
deployments sync.Map
}
func (p *Proxy) AddDeployment(deployment *Deployment) {
log.Printf("Adding deployment %s\n", deployment.URL)
p.deployments.Store(deployment.URL, deployment)
}
func (p *Proxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
host := r.Host
deployment, ok := p.deployments.Load(host)
if !ok {
http.Error(w, "Not found", http.StatusNotFound)
return
}
atomic.AddInt64(&deployment.(*Deployment).Proxy.activeRequests, 1)
deployment.(*Deployment).Proxy.proxy.ServeHTTP(w, r)
}
type DeploymentProxy struct {
deployment *Deployment
currentHead *Container
proxy *httputil.ReverseProxy
gracePeriod time.Duration
activeRequests int64
}
func NewDeploymentProxy(deployment *Deployment, head *Container) (*DeploymentProxy, error) {
containerJSON, err := dockerClient.ContainerInspect(context.Background(), string(head.ContainerID[:]))
if err != nil {
return nil, err
}
if containerJSON.NetworkSettings.IPAddress == "" {
return nil, fmt.Errorf("No IP address found for container %s", head.ContainerID[0:12])
}
containerUrl, err := url.Parse(fmt.Sprintf("http://%s:%d", containerJSON.NetworkSettings.IPAddress, deployment.Port))
if err != nil {
return nil, err
}
proxy := &httputil.ReverseProxy{
Director: func(req *http.Request) {
req.URL = containerUrl
req.Host = containerUrl.Host
},
Transport: &http.Transport{
MaxIdleConns: 100,
IdleConnTimeout: 90 * time.Second,
MaxIdleConnsPerHost: 100,
},
ModifyResponse: func(resp *http.Response) error {
atomic.AddInt64(&deployment.Proxy.activeRequests, -1)
return nil
},
}
return &DeploymentProxy{
deployment: deployment,
currentHead: head,
proxy: proxy,
gracePeriod: time.Second * 30,
activeRequests: 0,
}, nil
}
func (dp *DeploymentProxy) GracefulShutdown(oldContainers []*Container) {
ctx, cancel := context.WithTimeout(context.Background(), dp.gracePeriod)
defer cancel()
// Create a channel to signal when wait group is done
for {
select {
case <-ctx.Done():
break
default:
if atomic.LoadInt64(&dp.activeRequests) == 0 {
break
}
time.Sleep(time.Second)
}
if atomic.LoadInt64(&dp.activeRequests) == 0 || ctx.Err() != nil {
break
}
}
for _, container := range oldContainers {
err := RemoveDockerContainer(context.Background(), string(container.ContainerID[:]))
if err != nil {
log.Printf("Failed to remove container: %v\n", err)
}
}
}
func InitProxy(apps *AppManager) {
ReverseProxy = &Proxy{}
apps.Range(func(key, value interface{}) bool {
app := value.(*App)
ReverseProxy.AddDeployment(&app.Deployment)
return true
})
}
func InitReverseProxy() {
InitProxy(Apps)
port := os.Getenv("FLUXD_PROXY_PORT")
if port == "" {
port = "7465"
}
go func() {
log.Printf("Proxy server starting on http://127.0.0.1:%s\n", port)
if err := http.ListenAndServe(fmt.Sprintf(":%s", port), ReverseProxy); err != nil && err != http.ErrServerClosed {
log.Fatalf("Proxy server error: %v", err)
}
}()
}