// Supervise monitors the life of the Server and coordinates its shutdown.
// A shutdown occurs when the monitor returns, either because a health check
// fails or a user triggers a shutdown. If the shutdown is due to a health
// check failure, the Server is restarted. Supervise will block shutdown until
// all components have finished shutting down or a timeout occurs; if this
// happens, the Server will not automatically be restarted.
func (s *Server) Supervise() {
sd, err := s.mon.Monitor(s.hrt, s.killc)
if sd {
log.Infof("Server monitor triggered: told to shut down")
} else {
log.Errorf("Server monitor triggered: %v", err)
}
close(s.stopc)
done := make(chan struct{})
go func() {
s.wg.Wait()
close(done)
}()
select {
case <-done:
case <-time.After(shutdownTimeout):
log.Errorf("Timed out waiting for server to shut down. Panicking the server without cleanup.")
panic("Failed server shutdown. Panic")
}
if !sd {
log.Infof("Restarting server")
s.SetRestartServer(true)
s.Run()
s.SetRestartServer(false)
}
}
// ConnectToRegistry allows to disable_engine fleet agents to adapt its Registry
// to fleet leader changes regardless of whether is etcd or gRPC based.
func (r *RegistryMux) ConnectToRegistry(e *engine.Engine) {
for {
// We have to check if the leader has changed to etcd otherwise keep grpc connection
isGrpc, err := e.IsGrpcLeader()
// If there is not error then we are able to get the leader state and continue
// otherwise we have to wait
if err == nil {
if isGrpc {
if r.rpcRegistry != nil && r.rpcRegistry.IsRegistryReady() {
log.Infof("Reusing gRPC engine, connection is READY\n")
r.currentRegistry = r.rpcRegistry
} else {
if r.rpcRegistry != nil {
r.rpcRegistry.Close()
}
log.Infof("New engine supports gRPC, connecting\n")
r.rpcRegistry = NewRPCRegistry(r.rpcDialerNoEngine)
// connect to rpc registry
r.rpcRegistry.Connect()
r.currentRegistry = r.rpcRegistry
}
} else {
if r.rpcRegistry != nil {
r.rpcRegistry.Close()
}
// new leader is etcd-based
r.currentRegistry = r.etcdRegistry
}
}
time.Sleep(5 * time.Second)
}
}
func (e *Engine) rpcLeadership(leaseTTL time.Duration, machID string) lease.Lease {
var previousEngine string
if e.lease != nil {
previousEngine = e.lease.MachineID()
}
var l lease.Lease
if isLeader(e.lease, machID) {
l = rpcRenewLeadership(e.lManager, e.lease, engineVersion, leaseTTL)
} else {
l = rpcAcquireLeadership(e.registry, e.lManager, machID, engineVersion, leaseTTL)
}
// log all leadership changes
if l != nil && e.lease == nil && l.MachineID() != machID {
log.Infof("Engine leader is %s", l.MachineID())
} else if l != nil && e.lease != nil && l.MachineID() != e.lease.MachineID() {
log.Infof("Engine leadership changed from %s to %s", e.lease.MachineID(), l.MachineID())
}
e.lease = l
if e.lease != nil && previousEngine != e.lease.MachineID() {
engineState, err := e.getMachineState(e.lease.MachineID())
if err != nil {
log.Errorf("Failed to get machine state for machine %s %v", e.lease.MachineID(), err)
}
if engineState != nil {
log.Infof("Updating engine state... engineState: %v previous: %s lease: %v", engineState, previousEngine, e.lease)
go e.updateEngineState(*engineState)
}
}
return e.lease
}
func getConfig(flagset *flag.FlagSet, userCfgFile string) (*config.Config, error) {
opts := globalconf.Options{EnvPrefix: "FLEET_"}
if userCfgFile != "" {
// Fail hard if a user-provided config is not usable
fi, err := os.Stat(userCfgFile)
if err != nil {
log.Fatalf("Unable to use config file %s: %v", userCfgFile, err)
}
if fi.IsDir() {
log.Fatalf("Provided config %s is a directory, not a file", userCfgFile)
}
log.Infof("Using provided config file %s", userCfgFile)
opts.Filename = userCfgFile
} else if _, err := os.Stat(DefaultConfigFile); err == nil {
log.Infof("Using default config file %s", DefaultConfigFile)
opts.Filename = DefaultConfigFile
} else {
log.Infof("No provided or default config file found - proceeding without")
}
gconf, err := globalconf.NewWithOptions(&opts)
if err != nil {
return nil, err
}
gconf.ParseSet("", flagset)
cfg := config.Config{
Verbosity: (*flagset.Lookup("verbosity")).Value.(flag.Getter).Get().(int),
EtcdServers: (*flagset.Lookup("etcd_servers")).Value.(flag.Getter).Get().(pkg.StringSlice),
EtcdKeyPrefix: (*flagset.Lookup("etcd_key_prefix")).Value.(flag.Getter).Get().(string),
EtcdKeyFile: (*flagset.Lookup("etcd_keyfile")).Value.(flag.Getter).Get().(string),
EtcdCertFile: (*flagset.Lookup("etcd_certfile")).Value.(flag.Getter).Get().(string),
EtcdCAFile: (*flagset.Lookup("etcd_cafile")).Value.(flag.Getter).Get().(string),
EtcdRequestTimeout: (*flagset.Lookup("etcd_request_timeout")).Value.(flag.Getter).Get().(float64),
EngineReconcileInterval: (*flagset.Lookup("engine_reconcile_interval")).Value.(flag.Getter).Get().(float64),
PublicIP: (*flagset.Lookup("public_ip")).Value.(flag.Getter).Get().(string),
RawMetadata: (*flagset.Lookup("metadata")).Value.(flag.Getter).Get().(string),
AgentTTL: (*flagset.Lookup("agent_ttl")).Value.(flag.Getter).Get().(string),
VerifyUnits: (*flagset.Lookup("verify_units")).Value.(flag.Getter).Get().(bool),
TokenLimit: (*flagset.Lookup("token_limit")).Value.(flag.Getter).Get().(int),
AuthorizedKeysFile: (*flagset.Lookup("authorized_keys_file")).Value.(flag.Getter).Get().(string),
}
if cfg.VerifyUnits {
log.Error("Config option verify_units is no longer supported - ignoring")
}
if len(cfg.AuthorizedKeysFile) > 0 {
log.Error("Config option authorized_keys_file is no longer supported - ignoring")
}
if cfg.Verbosity > 0 {
log.EnableDebug()
}
return &cfg, nil
}
func (s *Server) Run() {
log.Infof("Establishing etcd connectivity")
var err error
for sleep := time.Second; ; sleep = pkg.ExpBackoff(sleep, time.Minute) {
_, err = s.hrt.Beat(s.mon.TTL)
if err == nil {
break
}
time.Sleep(sleep)
}
log.Infof("Starting server components")
s.stop = make(chan bool)
go s.Monitor()
go s.api.Available(s.stop)
go s.mach.PeriodicRefresh(machineStateRefreshInterval, s.stop)
go s.agent.Heartbeat(s.stop)
go s.aReconciler.Run(s.agent, s.stop)
if s.disableEngine {
log.Info("Not starting engine; disable-engine is set")
} else {
go s.engine.Run(s.engineReconcileInterval, s.stop)
}
beatchan := make(chan *unit.UnitStateHeartbeat)
go s.usGen.Run(beatchan, s.stop)
go s.usPub.Run(beatchan, s.stop)
}
func (ar *AgentReconciler) launchTasks(tasks []task, a *Agent) {
log.Debugf("AgentReconciler attempting tasks %s", tasks)
results := ar.tManager.Do(tasks, a)
for _, res := range results {
if res.err == nil {
log.Infof("AgentReconciler completed task: type=%s job=%s reason=%q", res.task.typ, res.task.unit.Name, res.task.reason)
} else {
log.Infof("AgentReconciler task failed: type=%s job=%s reason=%q err=%v", res.task.typ, res.task.unit.Name, res.task.reason, res.err)
}
}
}
func runRestartUnit(cCmd *cobra.Command, args []string) (exit int) {
if len(args) == 0 {
stderr("No units given")
return 0
}
units, err := findUnits(args)
if err != nil {
stderr("%v", err)
return 1
}
if err := lazyCreateUnits(cCmd, args); err != nil {
stderr("Error creating units: %v", err)
return 1
}
globalUnits := make([]schema.Unit, 0)
for _, unit := range units {
if suToGlobal(unit) {
globalUnits = append(globalUnits, unit)
continue
}
if job.JobState(unit.CurrentState) == job.JobStateInactive {
stderr("Unable to restart unit %s in state %s", unit.Name, job.JobStateInactive)
continue
} else if job.JobState(unit.CurrentState) == job.JobStateLoaded {
log.Infof("Unit(%s) already %s, starting.", unit.Name, job.JobStateLoaded)
exit = setUnitStateAndWait(unit, job.JobStateLaunched, getBlockAttempts(cCmd))
if exit == 1 {
return exit
}
continue
} else {
//stop and start it
exit = setUnitStateAndWait(unit, job.JobStateLoaded, getBlockAttempts(cCmd))
if exit == 1 {
return exit
}
exit = setUnitStateAndWait(unit, job.JobStateLaunched, getBlockAttempts(cCmd))
if exit == 1 {
return exit
}
}
log.Infof("Unit(%s) was restarted.", unit.Name)
}
if err := cmdGlobalMachineState(cCmd, globalUnits); err != nil {
stderr("Error restarting global units %v err:%v", globalUnits, err)
return 1
}
return
}
func (r *RegistryMux) rpcDialerNoEngine(_ string, timeout time.Duration) (net.Conn, error) {
ticker := time.Tick(dialRegistryReconnectTimeout)
// Timeout re-defined to call etcd every 5secs to get the leader
timeout = 5 * time.Second
check := time.After(timeout)
for {
select {
case <-check:
log.Errorf("Unable to connect to engine %s\n", r.currentEngine.PublicIP)
// Get the new engine leader of the cluster out of etcd
lease, err := r.leaseManager.GetLease(engineLeaderKeyPath)
// Key found
if err == nil && lease != nil {
var err error
machines, err := r.etcdRegistry.Machines()
if err != nil {
log.Errorf("Unable to get the machines of the cluster %v\n", err)
return nil, errors.New("Unable to get the machines of the cluster")
}
for _, s := range machines {
// Update the currentEngine with the new one... otherwise wait until
// there is one
if s.ID == lease.MachineID() {
// New leader has not gRPC capabilities enabled.
if !s.Capabilities.Has(machine.CapGRPC) {
log.Error("New leader engine has not gRPC enabled!")
return nil, errors.New("New leader engine has not gRPC enabled!")
}
r.currentEngine = s
log.Infof("Found a new engine to connect to: %s\n", r.currentEngine.PublicIP)
// Restore initial check configuration
timeout = 5 * time.Second
check = time.After(timeout)
}
}
} else {
timeout = 2 * time.Second
log.Errorf("Unable to get the leader engine, retrying in %v...", timeout)
check = time.After(timeout)
}
case <-ticker:
addr := fmt.Sprintf("%s:%d", r.currentEngine.PublicIP, rpcServerPort)
conn, err := net.Dial("tcp", addr)
if err == nil {
log.Infof("Connected to engine on %s\n", r.currentEngine.PublicIP)
return conn, nil
}
log.Errorf("Retry to connect to new engine: %+v", err)
}
}
}
func (s *Server) Run() {
log.Infof("Establishing etcd connectivity")
var err error
for sleep := time.Second; ; sleep = pkg.ExpBackoff(sleep, time.Minute) {
if s.restartServer {
_, err = s.hrt.Beat(s.mon.TTL)
if err == nil {
log.Infof("hrt.Beat() success")
break
}
} else {
_, err = s.hrt.Register(s.mon.TTL)
if err == nil {
log.Infof("hrt.Register() success")
break
}
}
log.Warningf("Server register machine failed: %v, retrying in %d sec.", err, sleep)
time.Sleep(sleep)
}
go s.Supervise()
log.Infof("Starting server components")
s.stopc = make(chan struct{})
s.wg = sync.WaitGroup{}
beatc := make(chan *unit.UnitStateHeartbeat)
components := []func(){
func() { s.api.Available(s.stopc) },
func() { s.mach.PeriodicRefresh(machineStateRefreshInterval, s.stopc) },
func() { s.agent.Heartbeat(s.stopc) },
func() { s.aReconciler.Run(s.agent, s.stopc) },
func() { s.usGen.Run(beatc, s.stopc) },
func() { s.usPub.Run(beatc, s.stopc) },
}
if s.disableEngine {
log.Info("Not starting engine; disable-engine is set")
} else {
components = append(components, func() { s.engine.Run(s.engineReconcileInterval, s.stopc) })
}
for _, f := range components {
f := f
s.wg.Add(1)
go func() {
f()
s.wg.Done()
}()
}
}
// Resolve attempts to yield a result from the configured action and endpoint. If a usable
// Result or error was not attained, nil values are returned.
func (ar *actionResolver) Resolve(cancel <-chan struct{}) (*Result, error) {
resp, body, err := ar.exhaust(cancel)
if err != nil {
log.Infof("Failed getting response from %v: %v", ar.endpoint, err)
return nil, nil
}
hdlr, ok := handlers[resp.StatusCode]
if !ok {
log.Infof("Response %s from %v unusable", resp.Status, ar.endpoint)
return nil, nil
}
return hdlr(resp, body)
}
func (m *systemdUnitManager) removeUnit(name string) (err error) {
log.Infof("Removing systemd unit %s", name)
// both DisableUnitFiles() and ResetFailedUnit() must be followed by
// removing the unit file. Otherwise "systemctl stop fleet" could end up
// hanging forever.
var errf error
func(name string) {
_, errf = m.systemd.DisableUnitFiles([]string{name}, true)
if errf != nil {
err = fmt.Errorf("%v, %v", err, errf)
}
}(name)
func(name string) {
errf = m.systemd.ResetFailedUnit(name)
if errf != nil {
err = fmt.Errorf("%v, %v", err, errf)
}
}(name)
ufPath := m.getUnitFilePath(name)
os.Remove(ufPath)
return err
}
func (m *systemdUnitManager) stopUnit(name string) {
if stat, err := m.systemd.StopUnit(name, "replace"); err != nil {
log.Errorf("Failed to stop systemd unit %s: %v", name, err)
} else {
log.Infof("Stopped systemd unit %s(%s)", name, stat)
}
}
func acquireLeadership(lManager lease.Manager, machID string, ver int, ttl time.Duration) lease.Lease {
existing, err := lManager.GetLease(engineLeaseName)
if err != nil {
log.Errorf("Unable to determine current lease: %v", err)
return nil
}
var l lease.Lease
if existing == nil {
l, err = lManager.AcquireLease(engineLeaseName, machID, ver, ttl)
if err != nil {
log.Errorf("Engine leadership acquisition failed: %v", err)
return nil
} else if l == nil {
log.Debugf("Unable to acquire engine leadership")
return nil
}
log.Infof("Engine leadership acquired")
metrics.ReportEngineLeader()
return l
}
if existing.Version() >= ver {
log.Debugf("Lease already held by Machine(%s) operating at acceptable version %d", existing.MachineID(), existing.Version())
return existing
}
rem := existing.TimeRemaining()
l, err = lManager.StealLease(engineLeaseName, machID, ver, ttl+rem, existing.Index())
if err != nil {
log.Errorf("Engine leadership steal failed: %v", err)
return nil
} else if l == nil {
log.Debugf("Unable to steal engine leadership")
return nil
}
log.Infof("Stole engine leadership from Machine(%s)", existing.MachineID())
metrics.ReportEngineLeader()
if rem > 0 {
log.Infof("Waiting %v for previous lease to expire before continuing reconciliation", rem)
<-time.After(rem)
}
return l
}
func (m *systemdUnitManager) enableUnit(name string) (bool, error) {
log.Infof("Enabling systemd unit %s", name)
ufPath := m.getUnitFilePath(name)
ok, _, err := m.systemd.EnableUnitFiles([]string{ufPath}, true, true)
return ok, err
}
// getUnitFromObject takes a *etcd.Node containing a Unit's jobModel, and
// instantiates and returns a representative *job.Unit, transitively fetching the
// associated UnitFile as necessary
func (r *EtcdRegistry) getUnitFromObjectNode(node *etcd.Node) (*job.Unit, error) {
var err error
var jm jobModel
if err = unmarshal(node.Value, &jm); err != nil {
return nil, err
}
var unit *unit.UnitFile
// New-style Jobs should have a populated UnitHash, and the contents of the Unit are stored separately in the Registry
if !jm.UnitHash.Empty() {
unit = r.getUnitByHash(jm.UnitHash)
if unit == nil {
log.Warningf("No Unit found in Registry for Job(%s)", jm.Name)
return nil, nil
}
} else {
// Old-style Jobs had "Payloads" instead of Units, also stored separately in the Registry
unit, err = r.getUnitFromLegacyPayload(jm.Name)
if err != nil {
log.Errorf("Error retrieving legacy payload for Job(%s)", jm.Name)
return nil, nil
} else if unit == nil {
log.Warningf("No Payload found in Registry for Job(%s)", jm.Name)
return nil, nil
}
log.Infof("Migrating legacy Payload(%s)", jm.Name)
if err := r.storeOrGetUnitFile(*unit); err != nil {
log.Warningf("Unable to migrate legacy Payload: %v", err)
}
jm.UnitHash = unit.Hash()
log.Infof("Updating Job(%s) with legacy payload Hash(%s)", jm.Name, jm.UnitHash)
if err := r.updateJobObjectNode(&jm, node.ModifiedIndex); err != nil {
log.Warningf("Unable to update Job(%s) with legacy payload Hash(%s): %v", jm.Name, jm.UnitHash, err)
}
}
ju := &job.Unit{
Name: jm.Name,
Unit: *unit,
}
return ju, nil
}
// TriggerStop asynchronously starts the unit identified by the given name.
// This function does not block for the underlying unit to actually stop.
func (m *systemdUnitManager) TriggerStop(name string) {
jobID, err := m.systemd.StopUnit(name, "replace", nil)
if err == nil {
log.Infof("Triggered systemd unit %s stop: job=%d", name, jobID)
} else {
log.Errorf("Failed to trigger systemd unit %s stop: %v", name, err)
}
}
// TriggerStart asynchronously starts the unit identified by the given name.
// This function does not block for the underlying unit to actually start.
func (m *systemdUnitManager) TriggerStart(name string) error {
jobID, err := m.systemd.StartUnit(name, "replace", nil)
if err != nil {
log.Errorf("Failed to trigger systemd unit %s start: %v", name, err)
return err
}
log.Infof("Triggered systemd unit %s start: job=%d", name, jobID)
return nil
}
func (m *systemdUnitManager) removeUnit(name string) {
log.Infof("Removing systemd unit %s", name)
m.systemd.DisableUnitFiles([]string{name}, true)
m.systemd.ResetFailedUnit(name)
ufPath := m.getUnitFilePath(name)
os.Remove(ufPath)
}
func (ar *AgentReconciler) launchTaskChain(tc taskChain, a *Agent) {
log.V(1).Infof("AgentReconciler attempting task chain: %s", tc)
reschan, err := ar.tManager.Do(tc, a)
if err != nil {
log.Infof("AgentReconciler task chain failed: chain=%s err=%v", tc, err)
return
}
go func() {
for res := range reschan {
if res.err == nil {
log.Infof("AgentReconciler completed task: type=%s job=%s reason=%q", res.task.typ, tc.job.Name, res.task.reason)
} else {
log.Infof("AgentReconciler task failed: type=%s job=%s reason=%q err=%v", res.task.typ, tc.job.Name, res.task.reason, res.err)
}
}
}()
}
func (e *Engine) unscheduleUnit(name, machID string) (err error) {
err = e.registry.UnscheduleUnit(name, machID)
if err != nil {
log.Errorf("Failed unscheduling Unit(%s) from Machine(%s): %v", name, machID, err)
} else {
log.Infof("Unscheduled Job(%s) from Machine(%s)", name, machID)
}
return
}
// attemptScheduleUnit tries to persist a scheduling decision in the
// Registry, returning true on success. If any communication with the
// Registry fails, false is returned.
func (e *Engine) attemptScheduleUnit(name, machID string) bool {
err := e.registry.ScheduleUnit(name, machID)
if err != nil {
log.Errorf("Failed scheduling Unit(%s) to Machine(%s): %v", name, machID, err)
return false
}
log.Infof("Scheduled Unit(%s) to Machine(%s)", name, machID)
return true
}
func (r *RegistryMux) EngineChanged(newEngine machine.MachineState) {
r.handlingEngineChange.Lock()
defer r.handlingEngineChange.Unlock()
stopServer := false
if r.currentEngine.ID != newEngine.ID {
stopServer = true
}
r.currentEngine = newEngine
log.Infof("Engine changed, checking capabilities %+v", newEngine)
if r.localMachine.State().Capabilities.Has(machine.CapGRPC) {
if r.rpcserver != nil && ((r.rpcRegistry != nil && !r.rpcRegistry.IsRegistryReady()) || stopServer) {
// If the engine changed, we need to stop the rpc server
r.rpcserver.Stop()
r.rpcserver = nil
}
if newEngine.ID == r.localMachine.State().ID {
if r.rpcserver == nil {
// start rpc server
log.Infof("Starting rpc server...\n")
var err error
r.rpcserver, err = NewRPCServer(r.etcdRegistry, newEngine.PublicIP)
if err != nil {
log.Fatalf("Unable to create rpc server %+v", err)
}
go func() {
errc := make(chan error, 1)
if errc <- r.rpcserver.Start(); <-errc != nil {
log.Fatalf("Failed to serve gRPC requests on listener: %v", <-errc)
}
}()
}
}
if newEngine.Capabilities.Has(machine.CapGRPC) {
if r.rpcRegistry != nil && r.rpcRegistry.IsRegistryReady() {
log.Infof("Reusing gRPC engine, connection is READY\n")
r.currentRegistry = r.rpcRegistry
} else {
log.Infof("New engine supports gRPC, connecting\n")
r.rpcRegistry = NewRPCRegistry(r.rpcDialer)
// connect to rpc registry
r.rpcRegistry.Connect()
r.currentRegistry = r.rpcRegistry
}
} else {
log.Infof("Falling back to etcd registry\n")
if r.rpcserver != nil {
// If the engine changed to a non gRPC leader, we need to stop the server
r.rpcserver.Stop()
}
r.currentRegistry = r.etcdRegistry
}
} else {
log.Infof("Falling back to etcd registry\n")
r.currentRegistry = r.etcdRegistry
}
}
func (m *systemdUnitManager) writeUnit(name string, contents string) error {
bContents := []byte(contents)
log.Infof("Writing systemd unit %s (%db)", name, len(bContents))
ufPath := m.getUnitFilePath(name)
err := ioutil.WriteFile(ufPath, bContents, os.FileMode(0644))
if err != nil {
return err
}
_, err = m.systemd.LinkUnitFiles([]string{ufPath}, true, true)
return err
}
// Supervise monitors the life of the Server and coordinates its shutdown.
// A shutdown occurs when the monitor returns, either because a health check
// fails or a user triggers a shutdown. If the shutdown is due to a health
// check failure, the Server is restarted. Supervise will block shutdown until
// all components have finished shutting down or a timeout occurs; if this
// happens, the Server will not automatically be restarted.
func (s *Server) Supervise() {
sd, err := s.mon.Monitor(s.hrt, s.killc)
if sd {
log.Infof("Server monitor triggered: told to shut down")
} else {
log.Errorf("Server monitor triggered: %v", err)
}
close(s.stopc)
done := make(chan struct{})
go func() {
s.wg.Wait()
close(done)
}()
select {
case <-done:
case <-time.After(shutdownTimeout):
log.Errorf("Timed out waiting for server to shut down")
sd = true
}
if !sd {
log.Infof("Restarting server")
s.Run()
}
}
func rpcRenewLeadership(lManager lease.Manager, l lease.Lease, ver int, ttl time.Duration) lease.Lease {
err := l.Renew(ttl)
if err != nil {
if eerr, ok := err.(*etcdErr.Error); ok && eerr.ErrorCode == etcdErr.EcodeKeyNotFound {
log.Errorf("Retry renew etcd operation that failed due to %v", err)
l, err = lManager.AcquireLease(engineLeaseName, l.MachineID(), ver, ttl)
if err != nil {
log.Errorf("Engine leadership re-acquisition failed: %v", err)
return nil
} else if l == nil {
log.Infof("Unable to re-acquire engine leadership")
return nil
}
log.Infof("Engine leadership re-acquired")
return l
} else {
log.Errorf("Engine leadership lost, renewal failed: %v", err)
return nil
}
}
log.Debugf("Engine leadership renewed")
return l
}
func doTask(t *task, e *Engine) (err error) {
switch t.Type {
case taskTypeUnscheduleUnit:
err = e.unscheduleUnit(t.JobName, t.MachineID)
case taskTypeAttemptScheduleUnit:
e.attemptScheduleUnit(t.JobName, t.MachineID)
default:
err = fmt.Errorf("unrecognized task type %q", t.Type)
}
if err == nil {
log.Infof("EngineReconciler completed task: %s", t)
}
return
}
func rpcAcquireLeadership(reg registry.Registry, lManager lease.Manager, machID string, ver int, ttl time.Duration) lease.Lease {
existing, err := lManager.GetLease(engineLeaseName)
if err != nil {
log.Errorf("Unable to determine current lease: %v", err)
return nil
}
var l lease.Lease
if (existing == nil && reg.UseEtcdRegistry()) || (existing == nil && !reg.IsRegistryReady()) {
l, err = lManager.AcquireLease(engineLeaseName, machID, ver, ttl)
if err != nil {
log.Errorf("Engine leadership acquisition failed: %v", err)
return nil
} else if l == nil {
log.Infof("Unable to acquire engine leadership")
return nil
}
log.Infof("Engine leadership acquired")
return l
}
if existing != nil && existing.Version() >= ver {
log.Debugf("Lease already held by Machine(%s) operating at acceptable version %d", existing.MachineID(), existing.Version())
return existing
}
// TODO(hector): Here we could add a possible SLA to determine when the leader
// is too busy. In such a case, we can trigger a new leader election
if (existing != nil && reg.UseEtcdRegistry()) || (existing != nil && !reg.IsRegistryReady()) {
rem := existing.TimeRemaining()
l, err = lManager.StealLease(engineLeaseName, machID, ver, ttl+rem, existing.Index())
if err != nil {
log.Errorf("Engine leadership steal failed: %v", err)
return nil
} else if l == nil {
log.Infof("Unable to steal engine leadership")
return nil
}
log.Infof("Stole engine leadership from Machine(%s)", existing.MachineID())
if rem > 0 {
log.Infof("Waiting %v for previous lease to expire before continuing reconciliation", rem)
<-time.After(rem)
}
return l
}
log.Infof("Engine leader is BUSY!")
return existing
}
func NewRPCServer(reg registry.Registry, addr string) (*rpcserver, error) {
s := &rpcserver{
etcdRegistry: reg,
mu: new(sync.Mutex),
localRegistry: newInmemoryRegistry(),
stop: make(chan struct{}),
}
var err error
tcpAddr, err := net.ResolveTCPAddr("tcp", fmt.Sprintf("%s:%d", addr, rpcServerPort))
if err != nil {
return nil, err
}
for it := 0; it < bindAddrMaxRetry; it++ {
s.listener, err = net.ListenTCP("tcp", tcpAddr)
if err == nil {
break
}
log.Infof("Retrying %d to bind %s address... %v", it, tcpAddr, err)
time.Sleep(bindRetryTimeout)
}
if err != nil {
return nil, err
}
s.grpcserver = grpc.NewServer()
s.localRegistry.LoadFrom(s.etcdRegistry)
pb.RegisterRegistryServer(s.grpcserver, s)
s.SetServingStatus(pb.HealthCheckResponse_NOT_SERVING)
machineStates, err := s.etcdRegistry.Machines()
if err != nil {
return nil, err
}
s.hasNonGRPCAgents = false
for _, state := range machineStates {
if !state.Capabilities.Has(machine.CapGRPC) {
log.Info("Fleet cluster has non gRPC agents!. Enabled unit state storage into etcd!")
s.hasNonGRPCAgents = true
break
}
}
return s, nil
}
func (r *RegistryMux) rpcDialer(_ string, timeout time.Duration) (net.Conn, error) {
ticker := time.Tick(dialRegistryReconnectTimeout)
alert := time.After(timeout)
for {
select {
case <-alert:
log.Errorf("Unable to connect to engine %s\n", r.currentEngine.PublicIP)
return nil, errors.New("Unable to connect to new engine, the client connection is closing")
case <-ticker:
addr := fmt.Sprintf("%s:%d", r.currentEngine.PublicIP, rpcServerPort)
conn, err := net.Dial("tcp", addr)
if err == nil {
log.Infof("Connected to engine on %s\n", r.currentEngine.PublicIP)
return conn, nil
}
log.Errorf("Retry to connect to new engine: %+v", err)
}
}
}
func ensureEngineVersionMatch(cReg registry.ClusterRegistry, expect int) bool {
v, err := cReg.EngineVersion()
if err != nil {
log.Errorf("Unable to determine cluster engine version")
return false
}
if v < expect {
err = cReg.UpdateEngineVersion(v, expect)
if err != nil {
log.Errorf("Failed updating cluster engine version from %d to %d: %v", v, expect, err)
return false
}
log.Infof("Updated cluster engine version from %d to %d", v, expect)
} else if v > expect {
log.Debugf("Cluster engine version higher than local engine version (%d > %d), unable to participate", v, expect)
return false
}
return true
}
