// RegisterHTTPForever is just like RegisterHTTP however it first tries to
// register forever until a response from kontrol is received. It's useful to
// use it during app initializations. After the registration a reconnect is
// automatically handled inside the RegisterHTTP method.
func (k *Kite) RegisterHTTPForever(kiteURL *url.URL) {
// Create the httpBackoffRegister that RegisterHTTPForever will
// use to backoff repeated register attempts.
httpRegisterBackOff := backoff.NewExponentialBackOff()
httpRegisterBackOff.InitialInterval = 30 * time.Second
httpRegisterBackOff.MaxInterval = 5 * time.Minute
httpRegisterBackOff.Multiplier = 1.7
httpRegisterBackOff.MaxElapsedTime = 0
register := func() error {
_, err := k.RegisterHTTP(kiteURL)
if err != nil {
k.Log.Error("Cannot register to Kontrol: %s Will retry after %d seconds",
err,
httpRegisterBackOff.NextBackOff()/time.Second)
return err
}
return nil
}
// this will retry register forever
err := backoff.Retry(register, httpRegisterBackOff)
if err != nil {
k.Log.Error("BackOff stopped retrying with Error '%s'", err)
}
}
func refreshFromSource() {
certData := bytes.NewBuffer([]byte{})
bo := backoff.NewExponentialBackOff()
bo.MaxElapsedTime = time.Minute
err := backoff.Retry(func() error {
src, err := http.Get(certDataSource)
if err != nil {
return err
}
defer src.Body.Close()
license, cvsID, objects := cert.ParseInput(src.Body)
fmt.Fprint(certData, license)
if len(cvsID) > 0 {
fmt.Fprint(certData, "CVS_ID "+cvsID+"\n")
}
cert.OutputTrustedCerts(certData, objects)
return nil
}, bo)
if err != nil {
log.Fatal(err)
}
saveToCache(strconv.FormatInt(time.Now().UTC().Unix(), 10), certData.Bytes())
latestCertificates = certData.Bytes()
}
func (as *APISelector) makeImageRequest(urlString string, bodyLines []string) (*apiSelectorImageResponse, error) {
var responseBody []byte
b := backoff.NewExponentialBackOff()
b.MaxInterval = 10 * time.Second
b.MaxElapsedTime = time.Minute
err := backoff.Retry(func() (err error) {
resp, err := http.Post(urlString, imageAPIRequestContentType,
strings.NewReader(strings.Join(bodyLines, "\n")+"\n"))
if err != nil {
return err
}
defer resp.Body.Close()
responseBody, err = ioutil.ReadAll(resp.Body)
return
}, b)
if err != nil {
return nil, err
}
imageResp := &apiSelectorImageResponse{
Data: []*apiSelectorImageRef{},
}
err = json.Unmarshal(responseBody, imageResp)
if err != nil {
return nil, err
}
return imageResp, nil
}
func (c *Client) makeRequest(request *batch) {
payload, err := json.Marshal(request)
if err != nil {
log.Printf("[Error] Batch failed to marshal: %v - %v", request, err)
return
}
bodyReader := bytes.NewReader(payload)
b := backoff.NewExponentialBackOff()
b.MaxElapsedTime = 10 * time.Second
err = backoff.Retry(func() error {
resp, err := http.Post(c.BaseEndpoint+"/v1/set", "application/json", bodyReader)
if err != nil {
return err
}
defer resp.Body.Close()
response := map[string]interface{}{}
dec := json.NewDecoder(resp.Body)
dec.Decode(&response)
if resp.StatusCode != http.StatusOK {
return fmt.Errorf("HTTP Post Request Failed, Status Code %d: %v", resp.StatusCode, response)
}
return nil
}, b)
if err != nil {
log.Printf("[Error] %v", err)
return
}
}
func (i *gceInstance) isPreempted(ctx gocontext.Context) (bool, error) {
if !i.ic.Preemptible {
return false, nil
}
listOpCall := i.provider.client.GlobalOperations.AggregatedList(i.provider.projectID).
Filter(fmt.Sprintf("targetId eq %d", i.instance.Id))
b := backoff.NewExponentialBackOff()
b.InitialInterval = 1 * time.Second
b.MaxElapsedTime = 1 * time.Minute
var preempted bool
err := backoff.Retry(func() error {
i.provider.apiRateLimit(ctx)
list, err := listOpCall.Do()
if err != nil {
return err
}
for _, item := range list.Items {
for _, op := range item.Operations {
if op.Kind == "compute#operation" && op.OperationType == "compute.instances.preempted" {
preempted = true
return nil
}
}
}
return nil
}, b)
return preempted, err
}
func (s *stepGenerateScript) Run(state multistep.StateBag) multistep.StepAction {
buildJob := state.Get("buildJob").(Job)
ctx := state.Get("ctx").(gocontext.Context)
b := backoff.NewExponentialBackOff()
b.MaxInterval = 10 * time.Second
b.MaxElapsedTime = time.Minute
var script []byte
err := backoff.Retry(func() (err error) {
script, err = s.generator.Generate(ctx, buildJob.RawPayload())
return
}, b)
if err != nil {
context.LoggerFromContext(ctx).WithField("err", err).Error("couldn't generate build script, erroring job")
err := buildJob.Error(ctx, "An error occurred while generating the build script.")
if err != nil {
context.LoggerFromContext(ctx).WithField("err", err).Error("couldn't requeue job")
}
return multistep.ActionHalt
}
context.LoggerFromContext(ctx).Info("generated script")
state.Put("script", script)
return multistep.ActionContinue
}
func makeJobBoardImagesRequest(urlString string) (*jobBoardImagesResponse, error) {
var responseBody []byte
b := backoff.NewExponentialBackOff()
b.MaxInterval = 10 * time.Second
b.MaxElapsedTime = time.Minute
err := backoff.Retry(func() (err error) {
resp, err := http.Get(urlString)
if err != nil {
return err
}
defer resp.Body.Close()
responseBody, err = ioutil.ReadAll(resp.Body)
return
}, b)
if err != nil {
return nil, err
}
imageResp := &jobBoardImagesResponse{
Data: []*jobBoardImageRef{},
}
err = json.Unmarshal(responseBody, imageResp)
if err != nil {
return nil, err
}
return imageResp, nil
}
func retryTask(c context.Context, ds appwrap.Datastore, taskIntf TaskInterface, jobKey *datastore.Key, taskKey *datastore.Key) error {
var job JobInfo
if j, err := getJob(ds, jobKey); err != nil {
return fmt.Errorf("getting job: %s", err)
} else {
job = j
}
time.Sleep(time.Duration(job.RetryCount) * 5 * time.Second)
if err := backoff.Retry(func() error {
var task JobTask
if err := ds.Get(taskKey, &task); err != nil {
return fmt.Errorf("getting task: %s", err)
}
task.Status = TaskStatusPending
if _, err := ds.Put(taskKey, &task); err != nil {
return fmt.Errorf("putting task: %s", err)
} else if err := taskIntf.PostTask(c, task.Url, job.JsonParameters); err != nil {
return fmt.Errorf("enqueuing task: %s", err)
}
logInfo(c, "retrying task %d/%d", task.Retries, job.RetryCount)
return nil
}, mrBackOff()); err != nil {
logInfo(c, "retryTask() failed after backoff attempts")
return err
} else {
return nil
}
}
// listenForNodeChanges listens for changes to node status using change feeds.
// This function will block until the query fails
func (c *Cluster) listenForNodeChanges() error {
// Start listening to changes from a random active node
node, hpr, err := c.GetNextNode()
if err != nil {
return err
}
q, err := newQuery(
DB("rethinkdb").Table("server_status").Changes(),
map[string]interface{}{},
c.opts,
)
if err != nil {
return fmt.Errorf("Error building query: %s", err)
}
cursor, err := node.Query(q)
if err != nil {
hpr.Mark(err)
return err
}
// Keep reading node status updates from changefeed
var result struct {
NewVal nodeStatus `gorethink:"new_val"`
OldVal nodeStatus `gorethink:"old_val"`
}
for cursor.Next(&result) {
addr := fmt.Sprintf("%s:%d", result.NewVal.Network.Hostname, result.NewVal.Network.ReqlPort)
addr = strings.ToLower(addr)
switch result.NewVal.Status {
case "connected":
// Connect to node using exponential backoff (give up after waiting 5s)
// to give the node time to start-up.
b := backoff.NewExponentialBackOff()
b.MaxElapsedTime = time.Second * 5
backoff.Retry(func() error {
node, err := c.connectNodeWithStatus(result.NewVal)
if err == nil {
if !c.nodeExists(node) {
c.addNode(node)
Log.WithFields(logrus.Fields{
"id": node.ID,
"host": node.Host.String(),
}).Debug("Connected to node")
}
}
return err
}, b)
}
}
err = cursor.Err()
hpr.Mark(err)
return err
}
func watch(src string) error {
loc, err := storage.ParseLocation(src)
if err != nil {
return err
}
watcher, err := sync.Watch(loc)
if err != nil {
return err
}
defer watcher.Stop()
// TODO: a better approach here would be to use a channel to retry on,
// then if you jacked up the config, it would pick up the change
// in the middle of all the retries. As it stands now it would take a
// minute to fix itself.
eb := backoff.NewExponentialBackOff()
eb.MaxElapsedTime = time.Minute
for range watcher.C {
log.Println("[watch] new version")
backoff.Retry(func() error {
err := apply(src)
if err != nil {
log.Printf("[watch] error installing: %v\n", err)
}
return err
}, eb)
}
return nil
}
func retry(op func() error) {
retry := backoff.NewExponentialBackOff()
retry.MaxElapsedTime = 2 * time.Minute
retry.MaxInterval = 10 * time.Second
backoff.Retry(op, retry)
}
func main() {
flag.Parse()
args := flag.Args()
if len(args) == 0 {
usage()
}
var b []byte
operation := func() error {
var err error
b, err = exec.Command(flag.Arg(0), args[1:]...).Output()
if err != nil {
log.Printf("err: %s", err)
}
return err
}
bf := backoff.NewExponentialBackOff()
second := func(i int) time.Duration {
return time.Duration(i) * time.Second
}
bf.MaxElapsedTime = second(*flagMaxElapsedTime)
bf.MaxInterval = second(*flagMaxInterval)
bf.InitialInterval = second(*flagInitialInterval)
err := backoff.Retry(operation, bf)
if err != nil {
fmt.Fprintf(os.Stderr, "operation failed: %s\n", err)
os.Exit(1)
}
fmt.Fprint(os.Stdout, string(b))
os.Exit(0)
}
func (b *Bridge) Add(containerId string) {
b.Lock()
defer b.Unlock()
container, err := b.docker.InspectContainer(containerId)
if err != nil {
log.Println("docksul: unable to inspect container:", containerId, err)
return
}
portDefs := make([][]string, 0)
for port, published := range container.NetworkSettings.Ports {
if len(published) > 0 {
p := strings.Split(string(port), "/")
portDefs = append(portDefs, []string{published[0].HostPort, p[0], p[1]})
}
}
multiservice := len(portDefs) > 1
for _, port := range portDefs {
service := b.buildService(container, port[0], port[1], port[2], multiservice)
err := backoff.Retry(func() error {
return b.consul.Agent().ServiceRegister(service)
}, backoff.NewExponentialBackoff())
if err != nil {
log.Println("docksul: unable to register service:", service, err)
continue
}
b.services[container.ID] = append(b.services[container.ID], service)
log.Println("docksul: added:", container.ID[:12], service.ID)
}
}
func (s *Sender) connect() {
for s.conn == nil {
var conn *conn
var err error
connect := func() error {
log.Printf("Connecting to %v", s.addr)
conn, err = newConn(s.addr, s.cert)
if err != nil {
log.Printf("Failed connecting to %v: %v; will retry", s.addr, err)
return err
}
return nil
}
if backoff.Retry(connect, backoff.NewExponentialBackOff()) != nil {
continue
}
log.Printf("Connected to %v", s.addr)
go s.read(conn)
s.conn = conn
}
}
// main reads configs, starts all gouroutines and waits until a message is in channel stop.
func main() {
backoff.Retry(testWebGuiPost, backoff.NewExponentialBackOff())
// Attempt to increase the limit on number of open files to the maximum allowed.
MaximizeOpenFileLimit()
allFolders := getFolders()
folders := filterFolders(allFolders)
if len(folders) == 0 {
log.Fatalln("No folders to be watched, exiting...")
}
stChans := make(map[string]chan STEvent, len(folders))
for _, folder := range folders {
Debug.Println("Installing watch for " + folder.Label)
stChan := make(chan STEvent)
stChans[folder.ID] = stChan
go watchFolder(folder, stChan)
}
// Note: Lose thread ownership of stChans
go watchSTEvents(stChans, allFolders)
go listenForSighup()
code := <-stop
OK.Println("Exiting")
os.Exit(code)
}
// createUnitWithRetry wraps CreateUnit of the fleet API with a retry.
func (f *FleetTunnel) createUnitWithRetry(unit *schema.Unit) error {
op := func() error {
return maskAny(f.cAPI.CreateUnit(unit))
}
if err := backoff.Retry(op, backoff.NewExponentialBackOff()); err != nil {
return maskAny(err)
}
return nil
}
// setUnitTargetStateWithRetry wraps SetUnitTargetState of the fleet API with a retry.
func (f *FleetTunnel) setUnitTargetStateWithRetry(name, target string) error {
op := func() error {
return maskAny(f.cAPI.SetUnitTargetState(name, target))
}
if err := backoff.Retry(op, backoff.NewExponentialBackOff()); err != nil {
return maskAny(err)
}
return nil
}
func (p proxy) ServeHTTP(res http.ResponseWriter, r *http.Request) {
bo := backoff.NewExponentialBackOff()
bo.MaxElapsedTime = 5 * time.Second
if err := backoff.Retry(func() error {
r.URL.Host = base.Host
r.URL.Scheme = base.Scheme
r.RequestURI = ""
r.Host = base.Host
suppliedToken := r.URL.Query().Get("token")
if authCookie, err := r.Cookie("grafana-proxy-auth"); err == nil {
suppliedToken = authCookie.Value
}
if cfg.Token != "" && suppliedToken != cfg.Token {
http.Error(res, "Please add the `?token=xyz` parameter with correct token", http.StatusForbidden)
return nil
}
resp, err := client.Do(r)
if err != nil {
return err
}
defer resp.Body.Close()
res.Header().Del("Content-Type")
for k, v := range resp.Header {
for _, v1 := range v {
res.Header().Add(k, v1)
}
}
if r.URL.Query().Get("token") != "" {
http.SetCookie(res, &http.Cookie{
Name: "grafana-proxy-auth",
Value: r.URL.Query().Get("token"),
MaxAge: 31536000, // 1 Year
Path: "/",
})
}
if resp.StatusCode == 401 {
loadLogin()
return fmt.Errorf("Need to relogin")
}
res.WriteHeader(resp.StatusCode)
written, _ := io.Copy(res, resp.Body)
log.Printf("%s %s?%s %d %d\n", r.Method, r.URL.Path, r.URL.RawQuery, resp.StatusCode, written)
return nil
}, bo); err != nil {
http.Error(res, fmt.Sprintf("Woot?\n%s", err), http.StatusInternalServerError)
}
}
// retryingFindTXT will, on any DNS failure, retry for up to 15 minutes before
// giving up and returning an empty []string of records
func retryingFindTXT(fqdn string) (records []string, ttl time.Duration, err error) {
err = backoff.Retry(
func() error {
records, ttl, err = findTXT(fqdn)
if err != nil {
log.Error("Retrying DNS query. Query failed with: %s", err.Error())
}
return err
}, backoff.NewExponentialBackOff())
return
}
func createTasks(ds appwrap.Datastore, jobKey *datastore.Key, taskKeys []*datastore.Key, tasks []JobTask, newStage JobStage) error {
now := time.Now()
firstId := taskKeys[0].IntID()
for i := range tasks {
tasks[i].StartTime = now
tasks[i].Job = jobKey
if taskKeys[i].IntID() < firstId {
firstId = taskKeys[i].IntID()
}
}
putSize := 64
i := 0
for i < len(tasks) {
if err := backoff.Retry(func() error {
last := i + putSize
if last > len(tasks) {
last = len(tasks)
}
if _, err := ds.PutMulti(taskKeys[i:last], tasks[i:last]); err != nil {
if putSize > 5 {
putSize /= 2
}
return err
}
i = last
return nil
}, mrBackOff()); err != nil {
return err
}
}
return runInTransaction(ds,
func(ds appwrap.Datastore) error {
var job JobInfo
if err := ds.Get(jobKey, &job); err != nil {
return err
}
job.TaskCount = len(tasks)
job.FirstTaskId = firstId
job.Stage = newStage
_, err := ds.Put(jobKey, &job)
return err
})
}
func startServiceContainer(tenantName string) error {
// do nothing in test mode
if testMode {
return nil
}
var err error
docker, err := utils.GetDockerClient()
if err != nil {
log.Errorf("Unable to connect to docker. Error %v", err)
return err
}
// pull the skydns image if it does not exist
imageName := defaultSkyDNSImage
_, err = docker.InspectImage(imageName)
if err != nil {
pullOperation := func() error {
err := docker.PullImage(imageName, nil)
if err != nil {
log.Errorf("Retrying to pull image: %s", imageName)
return err
}
return nil
}
err = backoff.Retry(pullOperation, backoff.NewExponentialBackOff())
if err != nil {
log.Errorf("Unable to pull image: %s", imageName)
return err
}
}
containerConfig := &dockerclient.ContainerConfig{
Image: imageName,
Env: []string{"ETCD_MACHINES=http://172.17.0.1:4001",
"SKYDNS_NAMESERVERS=8.8.8.8:53",
"SKYDNS_ADDR=0.0.0.0:53",
"SKYDNS_DOMAIN=" + tenantName}}
containerID, err := docker.CreateContainer(containerConfig, tenantName+"dns")
if err != nil {
log.Errorf("Error creating DNS container for tenant: %s. Error: %s", tenantName, err)
}
// Start the container
err = docker.StartContainer(containerID, nil)
if err != nil {
log.Errorf("Error starting DNS container for tenant: %s. Error: %s", tenantName, err)
}
return err
}
// unitWithRetry wraps Unit of the fleet API with a retry.
func (f *FleetTunnel) unitWithRetry(unitName string) (*schema.Unit, error) {
var u *schema.Unit
op := func() error {
var err error
u, err = f.cAPI.Unit(unitName)
return maskAny(err)
}
if err := backoff.Retry(op, backoff.NewExponentialBackOff()); err != nil {
return u, maskAny(err)
}
return u, nil
}
func getTask(ds appwrap.Datastore, taskKey *datastore.Key) (JobTask, error) {
var task JobTask
err := backoff.Retry(func() error {
return ds.Get(taskKey, &task)
}, mrBackOff())
if err != nil {
return JobTask{}, err
}
return task, nil
}
// Do should be called when the Request is fully configured.
func (r *Request) Do() (*http.Response, error) {
c := r.newClient()
res, err := doReq(r, c)
if err != nil {
op := r.operation(c)
err = backoff.Retry(op, r.backoff)
if err != nil {
return nil, err
}
}
return res, nil
}
func main() {
flag.Parse()
consulConfig := consulapi.DefaultConfig()
if flag.Arg(0) != "" {
consulConfig.Address = flag.Arg(0)
}
consul, err := consulapi.NewClient(consulConfig)
assert(err)
docker, err := dockerapi.NewClient(getopt("DOCKER_HOST", "unix:///var/run/docker.sock"))
assert(err)
log.Println("docksul: Getting Consul nodename...")
var nodeName string
err = backoff.Retry(func() (e error) {
nodeName, e = consul.Agent().NodeName()
if e != nil {
log.Println(e)
}
return
}, backoff.NewExponentialBackoff())
assert(err)
bridge := &Bridge{
docker: docker,
consul: consul,
nodeName: nodeName,
services: make(map[string][]*consulapi.AgentServiceRegistration),
}
containers, err := docker.ListContainers(dockerapi.ListContainersOptions{})
assert(err)
for _, listing := range containers {
bridge.Add(listing.ID[:12])
}
events := make(chan *dockerapi.APIEvents)
assert(docker.AddEventListener(events))
log.Println("docksul: Listening for Docker events...")
for msg := range events {
switch msg.Status {
case "start":
go bridge.Add(msg.ID)
case "die":
go bridge.Remove(msg.ID)
}
}
log.Fatal("docksul: docker event loop closed") // todo: reconnect?
}
// Update - Update document in azure blob storage
func (m *AzureBlob) Update(doc Document) error {
b := backoff.NewExponentialBackOff()
b.InitialInterval = 500 * time.Second
b.RandomizationFactor = 0.5
b.Multiplier = 2
b.MaxInterval = 60
b.MaxElapsedTime = 15 * time.Minute
return backoff.Retry(func() error {
r := strings.NewReader(doc.Content)
return m.blobStorage.CreateBlockBlobFromReader(
m.config.Container, doc.ID, uint64(r.Len()), r,
)
}, b)
}
// destroyUnitWithRetry wraps DestroyUnit of the fleet API with a retry.
func (f *FleetTunnel) destroyUnitWithRetry(unitName string) (notFound bool, err error) {
op := func() error {
if err := f.cAPI.DestroyUnit(unitName); client.IsErrorUnitNotFound(err) {
// Ignore 'Unit does not exist' error
notFound = true
return nil
}
return maskAny(err)
}
if err := backoff.Retry(op, backoff.NewExponentialBackOff()); err != nil {
return notFound, maskAny(err)
}
return notFound, nil
}
func loadLogin() {
backoff.Retry(func() error {
resp, err := client.PostForm(fmt.Sprintf("%s/login", cfg.BaseURL), url.Values{
"user": {cfg.User},
"password": {cfg.Pass},
})
if err != nil {
log.Printf("[ERR][loadLogin] %s", err)
return err
}
defer resp.Body.Close()
return nil
}, backoff.NewExponentialBackOff())
}
// TryRequest try operation timeout, and retry backoff
func TryRequest(url string, timeout time.Duration, condition Condition) error {
exponentialBackOff := backoff.NewExponentialBackOff()
exponentialBackOff.MaxElapsedTime = timeout
var res *http.Response
err := backoff.Retry(func() error {
var err error
res, err = http.Get(url)
if err != nil {
return err
}
return condition(res)
}, exponentialBackOff)
return err
}
func (i *gceInstance) stepWaitForInstanceDeleted(c *gceInstanceStopContext) multistep.StepAction {
logger := context.LoggerFromContext(c.ctx)
if i.ic.SkipStopPoll {
logger.Debug("skipping instance deletion polling")
c.errChan <- nil
return multistep.ActionContinue
}
logger.WithFields(logrus.Fields{
"duration": i.ic.StopPrePollSleep,
}).Debug("sleeping before first checking instance delete operation")
time.Sleep(i.ic.StopPrePollSleep)
zoneOpCall := i.client.ZoneOperations.Get(i.projectID,
i.ic.Zone.Name, c.instanceDeleteOp.Name)
b := backoff.NewExponentialBackOff()
b.InitialInterval = i.ic.StopPollSleep
b.MaxInterval = 10 * i.ic.StopPollSleep
b.MaxElapsedTime = 2 * time.Minute
err := backoff.Retry(func() error {
i.provider.apiRateLimit()
newOp, err := zoneOpCall.Do()
if err != nil {
return err
}
if newOp.Status == "DONE" {
if newOp.Error != nil {
return &gceOpError{Err: newOp.Error}
}
return nil
}
return errGCEInstanceDeletionNotDone
}, b)
c.errChan <- err
if err != nil {
return multistep.ActionHalt
}
return multistep.ActionContinue
}