ctrls.go

/*
	Copyright NetFoundry Inc.

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	https://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
*/

package env

import (
	"fmt"
	"github.com/cenkalti/backoff/v4"
	"github.com/michaelquigley/pfxlog"
	"github.com/openziti/foundation/v2/versions"
	"github.com/openziti/transport/v2"
	cmap "github.com/orcaman/concurrent-map/v2"
	"github.com/pkg/errors"
	"sync"
	"time"

	"github.com/openziti/channel/v2"
	"github.com/openziti/foundation/v2/concurrenz"
	"github.com/openziti/foundation/v2/errorz"
)

type NetworkControllers interface {
	UpdateControllerEndpoints(endpoints []string) bool
	GetAll() map[string]NetworkController
	GetNetworkController(ctrlId string) NetworkController
	AnyCtrlChannel() channel.Channel
	AllResponsiveCtrlChannels() []channel.Channel
	AnyValidCtrlChannel() channel.Channel
	GetCtrlChannel(ctrlId string) channel.Channel
	DefaultRequestTimeout() time.Duration
	ForEach(f func(ctrlId string, ch channel.Channel))
	Close() error
}

type CtrlDialer func(address transport.Address, bindHandler channel.BindHandler) error

func NewNetworkControllers(defaultRequestTimeout time.Duration, dialer CtrlDialer, heartbeatOptions *HeartbeatOptions) NetworkControllers {
	return &networkControllers{
		ctrlDialer:            dialer,
		heartbeatOptions:      heartbeatOptions,
		defaultRequestTimeout: defaultRequestTimeout,
		ctrlEndpoints:         cmap.New[struct{}](),
	}
}

type networkControllers struct {
	lock                  sync.Mutex
	ctrlDialer            CtrlDialer
	heartbeatOptions      *HeartbeatOptions
	defaultRequestTimeout time.Duration
	ctrlEndpoints         cmap.ConcurrentMap[string, struct{}]
	ctrls                 concurrenz.CopyOnWriteMap[string, NetworkController]
}

func (self *networkControllers) UpdateControllerEndpoints(addresses []string) bool {
	self.lock.Lock()
	defer self.lock.Unlock()

	changed := false

	log := pfxlog.Logger()
	endpoints := map[string]struct{}{}
	for _, endpoint := range addresses {
		endpoints[endpoint] = struct{}{}
	}

	for _, endpoint := range self.ctrlEndpoints.Keys() {
		if _, ok := endpoints[endpoint]; ok {
			// already known endpoint, don't need to try and connect in next step
			delete(endpoints, endpoint)
		} else {
			// existing endpoint is no longer valid, close and remove it
			log.WithField("endpoint", endpoints).Info("removing old ctrl endpoint")
			changed = true
			self.CloseAndRemoveByAddress(endpoint)
		}
	}

	for endpoint := range endpoints {
		log.WithField("endpoint", endpoints).Info("adding new ctrl endpoint")
		changed = true
		self.connectToControllerWithBackoff(endpoint)
	}

	return changed
}

func (self *networkControllers) connectToControllerWithBackoff(endpoint string) {
	log := pfxlog.Logger().WithField("endpoint", endpoint)

	addr, err := transport.ParseAddress(endpoint)
	if err != nil {
		log.WithField("endpoint", endpoint).WithError(err).Error("unable to parse endpoint address, ignoring")
		return
	}

	self.ctrlEndpoints.Set(endpoint, struct{}{})

	expBackoff := backoff.NewExponentialBackOff()
	expBackoff.InitialInterval = 50 * time.Millisecond
	expBackoff.MaxInterval = 5 * time.Minute
	expBackoff.MaxElapsedTime = 100 * 365 * 24 * time.Hour

	bindHandler := channel.BindHandlerF(func(binding channel.Binding) error {
		return self.Add(endpoint, binding.GetChannel())
	})

	operation := func() error {
		if !self.ctrlEndpoints.Has(endpoint) {
			return backoff.Permanent(errors.New("controller removed before connection established"))
		}
		err := self.ctrlDialer(addr, bindHandler)
		if err != nil {
			log.WithError(err).Error("unable to connect controller")
		}
		return err
	}

	log.Info("starting connection attempts")

	go func() {
		if err := backoff.Retry(operation, expBackoff); err != nil {
			log.WithError(err).Error("unable to connect controller, stopping retries.")
		} else {
			log.Info("successfully connected to controller")
		}
	}()
}

func (self *networkControllers) Add(address string, ch channel.Channel) error {
	ctrl := &networkCtrl{
		ch:               ch,
		address:          address,
		heartbeatOptions: self.heartbeatOptions,
	}

	if versionValue, found := ch.Underlay().Headers()[channel.HelloVersionHeader]; found {
		if versionInfo, err := versions.StdVersionEncDec.Decode(versionValue); err == nil {
			ctrl.versionInfo = versionInfo
		} else {
			return errors.Wrap(err, "could not parse version info from controller hello, closing connection")
		}
	} else {
		return errors.New("no version header provided")
	}

	if existing := self.ctrls.Get(ch.Id()); existing != nil {
		if !existing.Channel().IsClosed() {
			return fmt.Errorf("duplicate channel with id %v", ctrl.Channel().Id())
		}
	}
	self.ctrls.Put(ch.Id(), ctrl)
	return nil
}

func (self *networkControllers) GetAll() map[string]NetworkController {
	return self.ctrls.AsMap()
}

func (self *networkControllers) AnyCtrlChannel() channel.Channel {
	var current NetworkController
	for _, ctrl := range self.ctrls.AsMap() {
		if current == nil || ctrl.isMoreResponsive(current) {
			current = ctrl
		}
	}
	if current == nil {
		return nil
	}
	return current.Channel()
}

func (self *networkControllers) AllResponsiveCtrlChannels() []channel.Channel {
	var channels []channel.Channel
	for _, ctrl := range self.ctrls.AsMap() {
		if !ctrl.IsUnresponsive() {
			channels = append(channels, ctrl.Channel())
		}
	}
	return channels
}

func (self *networkControllers) AnyValidCtrlChannel() channel.Channel {
	delay := 10 * time.Millisecond
	for {
		result := self.AnyCtrlChannel()
		if result != nil {
			return result
		}
		time.Sleep(delay)
		delay = delay * 2
		if delay >= time.Minute {
			delay = time.Minute
		}
	}
}

func (self *networkControllers) GetCtrlChannel(controllerId string) channel.Channel {
	if ctrl := self.ctrls.Get(controllerId); ctrl != nil {
		return ctrl.Channel()
	}
	return nil
}

func (self *networkControllers) GetNetworkController(controllerId string) NetworkController {
	return self.ctrls.Get(controllerId)
}

func (self *networkControllers) DefaultRequestTimeout() time.Duration {
	return self.defaultRequestTimeout
}

func (self *networkControllers) ForEach(f func(controllerId string, ch channel.Channel)) {
	for controllerId, ctrl := range self.ctrls.AsMap() {
		f(controllerId, ctrl.Channel())
	}
}

func (self *networkControllers) Close() error {
	var errList errorz.MultipleErrors
	self.ForEach(func(_ string, ch channel.Channel) {
		if err := ch.Close(); err != nil {
			errList = append(errList, err)
		}
	})
	return errList.ToError()
}

func (self *networkControllers) CloseAndRemoveByAddress(address string) {
	self.ctrlEndpoints.Remove(address)

	for id, ctrl := range self.ctrls.AsMap() {
		if ctrl.Address() == address {
			self.ctrls.Delete(id)
			if err := ctrl.Channel().Close(); err != nil {
				pfxlog.Logger().WithField("ctrlId", id).WithField("endpoint", address).WithError(err).Error("error closing channel to controller")
			}
		}
	}
}