/
servermanager.go
175 lines (152 loc) · 4.11 KB
/
servermanager.go
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/*
Copyright 2016-2017 gtalent2@gmail.com
This Source Code Form is subject to the terms of the Mozilla Public
License, v. 2.0. If a copy of the MPL was not distributed with this
file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
package main
import (
"log"
"net"
"strconv"
"time"
)
const (
servermanagerSpinup = iota
servermanagerSpindown
serverManagerStop
)
type serverManagerEvent struct {
eventType int
tcpConn *net.TCPConn
}
/*
ServerHandler is an interface for spinning up and spinning down servers.
*/
type ServerHandler interface {
// Takes snapshot name, and returns the IP to connect to.
Spinup(name string) (string, error)
Spindown(name string) error
}
type serverManager struct {
name string
ports []int
in chan serverManagerEvent
done chan int
connStatus chan connStatus
lastKeepAliveTime time.Time
server ServerHandler
activityTimeout time.Duration
}
func newServerManager(name string, server ServerHandler, settings settings) *serverManager {
sm := new(serverManager)
sm.name = name
sm.ports = settings.Servers[name].Ports
sm.in = make(chan serverManagerEvent)
sm.done = make(chan int)
sm.connStatus = make(chan connStatus)
sm.server = server
sm.lastKeepAliveTime = time.Now()
activityTimeout, err := time.ParseDuration(settings.Servers[sm.name].ActivityTimeout)
if err != nil { // invalid timeout, default to 5 minutes
activityTimeout = time.Duration(5 * time.Minute)
}
sm.activityTimeout = activityTimeout
log.Println("serverManager: ", name, " has activity timeout of ", sm.activityTimeout.String())
return sm
}
/*
Serves channel requests.
*/
func (me *serverManager) Serve() {
// TODO: see if server is currently up, and setup port forwarding if so
ticker := time.NewTicker(1 * time.Minute)
// event loop
for running := true; running; {
select {
case status := <-me.connStatus:
if status.Status == connActive {
me.lastKeepAliveTime = time.Now()
}
case action := <-me.in:
running = me.serveAction(action)
case <-ticker.C:
if time.Since(me.lastKeepAliveTime) > me.activityTimeout {
running = me.serveAction(serverManagerEvent{eventType: servermanagerSpindown})
}
}
}
ticker.Stop()
// notify done
me.done <- 0
}
/*
Sends the serve loop a spinup message.
*/
func (me *serverManager) Spinup(c *net.TCPConn) {
me.in <- serverManagerEvent{eventType: servermanagerSpinup, tcpConn: c}
}
/*
Sends the serve loop a spindown message.
*/
func (me *serverManager) Spindown() {
me.in <- serverManagerEvent{eventType: servermanagerSpindown}
}
/*
Sends the serve loop a quit message.
*/
func (me *serverManager) Stop() {
me.in <- serverManagerEvent{eventType: serverManagerStop}
}
func (me *serverManager) Done() {
<-me.done
}
func (me *serverManager) setupListener(port int) {
portStr := strconv.Itoa(port)
addr, err := net.ResolveTCPAddr("tcp", "0.0.0.0:"+portStr)
if err != nil {
log.Print("Could not resolve port and listen address:", err)
return
}
// listen on port
go func() {
l, err := net.ListenTCP("tcp", addr)
if err != nil {
log.Print("Could not listen for TCP connection:", err)
} else {
for {
conn, err := l.AcceptTCP()
if err != nil {
log.Print("Could not accept TCP connection:", err)
} else { // connection accepted
// spinup machine
me.Spinup(conn)
}
}
}
}()
}
func (me *serverManager) serveAction(event serverManagerEvent) bool {
running := true
switch event.eventType {
case servermanagerSpinup:
targetIP, err := me.server.Spinup(me.name)
me.lastKeepAliveTime = time.Now()
if err == nil {
log.Println("serverManager: Got IP for", me.name+":", targetIP)
wanAddr := event.tcpConn.LocalAddr().String()
_, port, _ := net.SplitHostPort(wanAddr)
go portForward(event.tcpConn, targetIP, port, me.connStatus)
} else {
log.Println("serverManager: Could not spin up "+me.name+":", err)
}
case servermanagerSpindown:
err := me.server.Spindown(me.name)
if err != nil {
log.Println("serverManager: Could not spin down "+me.name+":", err)
}
case serverManagerStop:
running = false
}
return running
}