func Init(docker *goDocker.Client, newContChan chan<- goDocker.Container, removeContChan chan<- string, drawStatsChan chan<- StatsMsg) {
dockerEventChan = make(chan *goDocker.APIEvents, 10)
statsResultsChan = make(chan StatsResult)
statsResultsDoneChan = make(chan string)
dockerClient = docker
err := docker.AddEventListener(dockerEventChan)
if err != nil {
panic("Failed to add event listener: " + err.Error())
}
go statsRenderingRoutine(drawStatsChan)
go dockerEventRoutingRoutine(dockerEventChan, newContChan, removeContChan)
containers, _ := dockerClient.ListContainers(goDocker.ListContainersOptions{})
Info.Println("Listing intial", len(containers), "containers as started")
for _, cont := range containers {
Info.Println("Marking", cont.ID, "as started")
dockerEventChan <- &goDocker.APIEvents{ID: cont.ID, Status: "start"}
//startedContainerChan <- cont.ID
}
}
// RegisterDockerEventListener registers function as event listener with docker.
// laziness defines how many seconds to wait, after an event is received, until a refresh is triggered
func RegisterDockerEventListener(client *docker.Client, function func(), wg *sync.WaitGroup, laziness int) {
wg.Add(1)
defer wg.Done()
events := make(chan *docker.APIEvents)
defer close(events)
err := client.AddEventListener((chan<- *docker.APIEvents)(events))
if err != nil {
log.Fatalf("Unable to add docker event listener: %s", err)
}
defer client.RemoveEventListener(events)
log.Info("Listening to docker events...")
for {
event := <-events
if event == nil {
continue
}
if event.Status == "start" || event.Status == "stop" || event.Status == "die" {
log.Debug("Received event %s for container %s", event.Status, event.ID[:12])
Refresh.Mu.Lock()
if !Refresh.IsTriggered {
log.Info("Triggering refresh in %d seconds", laziness)
Refresh.timer = time.AfterFunc(time.Duration(laziness)*time.Second, function)
Refresh.IsTriggered = true
}
Refresh.Mu.Unlock()
}
}
}
func main() {
logger = log.New(os.Stdout, "logger: ", log.Lshortfile|log.Ldate|log.Ltime)
var VERSION = os.Getenv("CCP_VERSION")
logger.Println("dnsbridgeserver " + VERSION + ": starting")
getEnvVars()
var dockerConnected = false
var tries = 0
var docker *dockerapi.Client
var err error
for tries = 0; tries < MAX_TRIES; tries++ {
docker, err = dockerapi.NewClient(DOCKER_URL)
err = docker.Ping()
if err != nil {
logger.Println("could not ping docker host")
logger.Println("sleeping and will retry in %d sec\n", delaySeconds)
time.Sleep(delay)
} else {
logger.Println("no err in connecting to docker")
dockerConnected = true
break
}
}
if dockerConnected == false {
logger.Println("failing, could not connect to docker after retries")
panic("cant connect to docker")
}
events := make(chan *dockerapi.APIEvents)
assert(docker.AddEventListener(events))
logger.Println("dnsbridgeserver: Listening for Docker events...")
for msg := range events {
switch msg.Status {
//case "start", "create":
case "start":
logger.Println("event: " + msg.Status + " ID=" + msg.ID + " From:" + msg.From)
dnsbridgeapi.Action(logger, msg.Status, msg.ID, docker, TTL, CONSUL_URL, DOMAIN)
case "stop":
logger.Println("event: " + msg.Status + " ID=" + msg.ID + " From:" + msg.From)
dnsbridgeapi.Action(logger, msg.Status, msg.ID, docker, TTL, CONSUL_URL, DOMAIN)
case "destroy":
logger.Println("event: " + msg.Status + " ID=" + msg.ID + " From:" + msg.From)
dnsbridgeapi.Action(logger, msg.Status, msg.ID, docker, TTL, CONSUL_URL, DOMAIN)
case "die":
logger.Println("event: " + msg.Status + " ID=" + msg.ID + " From:" + msg.From)
default:
logger.Println("event: " + msg.Status)
}
}
}
func RunPool(config *Config, client *docker.Client) {
chEvents := make(chan *docker.APIEvents)
pools = make(map[string]*Pool)
// Setup docker event listener
if err := client.AddEventListener(chEvents); err != nil {
log.Fatalln(err)
}
go func() {
for {
event := <-chEvents
if event == nil {
continue
}
if event.Status == "die" {
for _, pool := range pools {
if pool.Exists(event.ID) {
log.Println("pool's container got destroyed:", event.ID)
pool.Remove(event.ID)
}
}
}
}
}()
for _, cfg := range config.Pools {
if cfg.Capacity < 1 {
continue
}
log.Println("initializing pool for:", cfg.Image)
pool, err := NewPool(config, client, cfg.Image, cfg.Capacity, cfg.Standby)
if err != nil {
log.Fatalln(err)
}
err = pool.Load()
if err != nil {
log.Fatalln(err)
}
go pool.Monitor()
pools[cfg.Image] = pool
}
}
func generateFromEvents(client *docker.Client, configs ConfigFile) {
configs = configs.filterWatches()
if len(configs.Config) == 0 {
return
}
wg.Add(1)
defer wg.Done()
for {
if client == nil {
var err error
endpoint, err := getEndpoint()
if err != nil {
log.Printf("Bad endpoint: %s", err)
time.Sleep(10 * time.Second)
continue
}
client, err = NewDockerClient(endpoint)
if err != nil {
log.Printf("Unable to connect to docker daemon: %s", err)
time.Sleep(10 * time.Second)
continue
}
generateFromContainers(client)
}
eventChan := make(chan *docker.APIEvents, 100)
defer close(eventChan)
watching := false
for {
if client == nil {
break
}
err := client.Ping()
if err != nil {
log.Printf("Unable to ping docker daemon: %s", err)
if watching {
client.RemoveEventListener(eventChan)
watching = false
client = nil
}
time.Sleep(10 * time.Second)
break
}
if !watching {
err = client.AddEventListener(eventChan)
if err != nil && err != docker.ErrListenerAlreadyExists {
log.Printf("Error registering docker event listener: %s", err)
time.Sleep(10 * time.Second)
continue
}
watching = true
log.Println("Watching docker events")
}
select {
case event := <-eventChan:
if event == nil {
if watching {
client.RemoveEventListener(eventChan)
watching = false
client = nil
}
break
}
if event.Status == "start" || event.Status == "stop" || event.Status == "die" {
log.Printf("Received event %s for container %s", event.Status, event.ID[:12])
generateFromContainers(client)
}
case <-time.After(10 * time.Second):
// check for docker liveness
}
}
}
}
func registerContainers(docker *dockerapi.Client, events chan *dockerapi.APIEvents, dns resolver.Resolver, containerDomain string, hostIP net.IP) error {
// TODO add an options struct instead of passing all as parameters
// though passing the events channel from an options struct was triggering
// data race warnings within AddEventListener, so needs more investigation
if events == nil {
events = make(chan *dockerapi.APIEvents)
}
if err := docker.AddEventListener(events); err != nil {
return err
}
if !strings.HasPrefix(containerDomain, ".") {
containerDomain = "." + containerDomain
}
getAddress := func(container *dockerapi.Container) (net.IP, error) {
for {
if container.NetworkSettings.IPAddress != "" {
return net.ParseIP(container.NetworkSettings.IPAddress), nil
}
if container.HostConfig.NetworkMode == "host" {
if hostIP == nil {
return nil, errors.New("IP not available with network mode \"host\"")
} else {
return hostIP, nil
}
}
if strings.HasPrefix(container.HostConfig.NetworkMode, "container:") {
otherId := container.HostConfig.NetworkMode[len("container:"):]
var err error
container, err = docker.InspectContainer(otherId)
if err != nil {
return nil, err
}
continue
}
return nil, fmt.Errorf("unknown network mode", container.HostConfig.NetworkMode)
}
}
addContainer := func(containerId string) error {
container, err := docker.InspectContainer(containerId)
if err != nil {
return err
}
addr, err := getAddress(container)
if err != nil {
return err
}
err = dns.AddHost(containerId, addr, container.Config.Hostname, container.Name[1:]+containerDomain)
if err != nil {
return err
}
env := parseContainerEnv(container.Config.Env, "DNS_")
if dnsDomains, ok := env["DNS_RESOLVES"]; ok {
if dnsDomains == "" {
return errors.New("empty DNS_RESOLVES, should contain a comma-separated list with at least one domain")
}
port := 53
if portString := env["DNS_PORT"]; portString != "" {
port, err = strconv.Atoi(portString)
if err != nil {
return errors.New("invalid DNS_PORT \"" + portString + "\", should contain a number")
}
}
domains := strings.Split(dnsDomains, ",")
err = dns.AddUpstream(containerId, addr, port, domains...)
if err != nil {
return err
}
}
if bridge := container.NetworkSettings.Bridge; bridge != "" {
bridgeAddr := net.ParseIP(container.NetworkSettings.Gateway)
err = dns.AddHost("bridge:"+bridge, bridgeAddr, bridge)
if err != nil {
return err
}
}
return nil
}
containers, err := docker.ListContainers(dockerapi.ListContainersOptions{})
if err != nil {
return err
}
for _, listing := range containers {
if err := addContainer(listing.ID); err != nil {
log.Printf("error adding container %s: %s\n", listing.ID[:12], err)
}
}
if err = dns.Listen(); err != nil {
return err
}
defer dns.Close()
for msg := range events {
go func(msg *dockerapi.APIEvents) {
switch msg.Status {
case "start":
if err := addContainer(msg.ID); err != nil {
log.Printf("error adding container %s: %s\n", msg.ID[:12], err)
}
case "die":
dns.RemoveHost(msg.ID)
dns.RemoveUpstream(msg.ID)
}
}(msg)
}
return errors.New("docker event loop closed")
}