90 lines
1.9 KiB
Go
90 lines
1.9 KiB
Go
package consul
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import (
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"log"
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"math/rand"
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"sync"
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"time"
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cstructs "github.com/hashicorp/nomad/client/driver/structs"
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)
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// CheckRunner runs a given check in a specific interval and update a
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// corresponding Consul TTL check
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type CheckRunner struct {
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check Check
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runCheck func(Check)
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logger *log.Logger
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stop bool
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stopCh chan struct{}
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stopLock sync.Mutex
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started bool
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startedLock sync.Mutex
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}
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// NewCheckRunner configures and returns a CheckRunner
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func NewCheckRunner(check Check, runCheck func(Check), logger *log.Logger) *CheckRunner {
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cr := CheckRunner{
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check: check,
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runCheck: runCheck,
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logger: logger,
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stopCh: make(chan struct{}),
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}
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return &cr
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}
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// Start is used to start the check. The check runs until stop is called
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func (r *CheckRunner) Start() {
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r.startedLock.Lock()
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defer r.startedLock.Unlock()
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if r.started {
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return
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}
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r.stopLock.Lock()
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defer r.stopLock.Unlock()
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go r.run()
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r.started = true
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}
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// Stop is used to stop the check.
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func (r *CheckRunner) Stop() {
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r.stopLock.Lock()
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defer r.stopLock.Unlock()
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if !r.stop {
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r.stop = true
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close(r.stopCh)
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}
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}
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// run is invoked by a goroutine to run until Stop() is called
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func (r *CheckRunner) run() {
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// Get the randomized initial pause time
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initialPauseTime := randomStagger(r.check.Interval())
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r.logger.Printf("[DEBUG] agent: pausing %v before first invocation of %s", initialPauseTime, r.check.ID())
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next := time.NewTimer(initialPauseTime)
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for {
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select {
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case <-next.C:
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r.runCheck(r.check)
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next.Reset(r.check.Interval())
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case <-r.stopCh:
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next.Stop()
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return
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}
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}
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}
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// Check is an interface which check providers can implement for Nomad to run
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type Check interface {
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Run() *cstructs.CheckResult
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ID() string
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Interval() time.Duration
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Timeout() time.Duration
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}
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// Returns a random stagger interval between 0 and the duration
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func randomStagger(intv time.Duration) time.Duration {
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return time.Duration(uint64(rand.Int63()) % uint64(intv))
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}
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