mirror of
https://github.com/gravitational/teleport
synced 2024-10-21 09:44:51 +00:00
89 lines
2.8 KiB
Go
89 lines
2.8 KiB
Go
/*
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Copyright 2018 Gravitational, Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package service
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import (
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"sync/atomic"
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"time"
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"github.com/gravitational/teleport/lib/defaults"
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)
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const (
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// stateOK means Teleport is operating normally.
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stateOK = 0
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// stateRecovering means Teleport has begun recovering from a degraded state.
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stateRecovering = 1
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// stateDegraded means some kind of connection error has occured to put
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// Teleport into a degraded state.
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stateDegraded = 2
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)
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// processState tracks the state of the Teleport process.
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type processState struct {
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process *TeleportProcess
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recoveryTime time.Time
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currentState int64
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}
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// newProcessState returns a new FSM that tracks the state of the Teleport process.
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func newProcessState(process *TeleportProcess) *processState {
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return &processState{
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process: process,
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recoveryTime: process.Clock.Now(),
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currentState: stateOK,
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}
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}
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// Process updates the state of Teleport.
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func (f *processState) Process(event Event) {
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switch event.Name {
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// Ready event means Teleport has started successfully.
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case TeleportReadyEvent:
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atomic.StoreInt64(&f.currentState, stateOK)
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f.process.Infof("Detected that service started and joined the cluster successfully.")
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// If a degraded event was received, always change the state to degraded.
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case TeleportDegradedEvent:
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atomic.StoreInt64(&f.currentState, stateDegraded)
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f.process.Infof("Detected Teleport is running in a degraded state.")
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// If the current state is degraded, and a OK event has been
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// received, change the state to recovering. If the current state is
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// recovering and a OK events is received, if it's been longer
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// than the recovery time (2 time the server heartbeat ttl), change
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// state to OK.
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case TeleportOKEvent:
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switch atomic.LoadInt64(&f.currentState) {
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case stateDegraded:
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atomic.StoreInt64(&f.currentState, stateRecovering)
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f.recoveryTime = f.process.Clock.Now()
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f.process.Infof("Teleport is recovering from a degraded state.")
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case stateRecovering:
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if f.process.Clock.Now().Sub(f.recoveryTime) > defaults.ServerHeartbeatTTL*2 {
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atomic.StoreInt64(&f.currentState, stateOK)
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f.process.Infof("Teleport has recovered from a degraded state.")
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}
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}
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}
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}
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// GetState returns the current state of the system.
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func (f *processState) GetState() int64 {
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return atomic.LoadInt64(&f.currentState)
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}
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