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Lazily retry triggered alerts in case of failure

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This commit is contained in:
TwinProduction 2021-01-21 16:14:32 -05:00
parent e9ac115a95
commit 3204a79eb6
4 changed files with 162 additions and 213 deletions
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4
alerting/provider/custom/custom.go
View file

@ -2,6 +2,7 @@ package custom
import (
"bytes"
"errors"
"fmt"
"io/ioutil"
"net/http"
@ -76,6 +77,9 @@ func (provider *AlertProvider) buildHTTPRequest(serviceName, alertDescription st
// Send a request to the alert provider and return the body
func (provider *AlertProvider) Send(serviceName, alertDescription string, resolved bool) ([]byte, error) {
if os.Getenv("MOCK_ALERT_PROVIDER") == "true" {
if os.Getenv("MOCK_ALERT_PROVIDER_ERROR") == "true" {
return nil, errors.New("error")
}
return []byte("{}"), nil
}
request := provider.buildHTTPRequest(serviceName, alertDescription, resolved)

6
core/alert.go
View file

@ -26,6 +26,12 @@ type Alert struct {
// Triggered is used to determine whether an alert has been triggered. When an alert is resolved, this value
// should be set back to false. It is used to prevent the same alert from going out twice.
//
// This value should only be modified if the provider.AlertProvider's Send function does not return an error for an
// alert that hasn't been triggered yet. This doubles as a lazy retry. The reason why this behavior isn't also
// applied for alerts that are already triggered and has become "healthy" again is to prevent a case where, for
// some reason, the alert provider always returns errors when trying to send the resolved notification
// (SendOnResolved).
Triggered bool
}

16
watchdog/alerting.go
View file

@ -26,18 +26,18 @@ func handleAlertsToTrigger(service *core.Service, result *core.Result, cfg *conf
service.NumberOfFailuresInARow++
for _, alert := range service.Alerts {
// If the alert hasn't been triggered, move to the next one
if !alert.Enabled || alert.FailureThreshold != service.NumberOfFailuresInARow {
if !alert.Enabled || alert.FailureThreshold > service.NumberOfFailuresInARow {
continue
}
if alert.Triggered {
if cfg.Debug {
log.Printf("[watchdog][handleAlertsToTrigger] Alert with description='%s' has already been TRIGGERED, skipping", alert.Description)
log.Printf("[watchdog][handleAlertsToTrigger] Alert for service=%s with description='%s' has already been TRIGGERED, skipping", service.Name, alert.Description)
}
continue
}
alertProvider := config.GetAlertingProviderByAlertType(cfg, alert.Type)
if alertProvider != nil && alertProvider.IsValid() {
log.Printf("[watchdog][handleAlertsToTrigger] Sending %s alert because alert with description='%s' has been TRIGGERED", alert.Type, alert.Description)
log.Printf("[watchdog][handleAlertsToTrigger] Sending %s alert because alert for service=%s with description='%s' has been TRIGGERED", alert.Type, service.Name, alert.Description)
customAlertProvider := alertProvider.ToCustomAlertProvider(service, alert, result, false)
// TODO: retry on error
var err error
@ -47,7 +47,7 @@ func handleAlertsToTrigger(service *core.Service, result *core.Result, cfg *conf
if body, err = customAlertProvider.Send(service.Name, alert.Description, false); err == nil {
var response pagerDutyResponse
if err = json.Unmarshal(body, &response); err != nil {
log.Printf("[watchdog][handleAlertsToTrigger] Ran into error unmarshaling pager duty response: %s", err.Error())
log.Printf("[watchdog][handleAlertsToTrigger] Ran into error unmarshaling pagerduty response: %s", err.Error())
} else {
alert.ResolveKey = response.DedupKey
}
@ -57,7 +57,7 @@ func handleAlertsToTrigger(service *core.Service, result *core.Result, cfg *conf
_, err = customAlertProvider.Send(service.Name, alert.Description, false)
}
if err != nil {
log.Printf("[watchdog][handleAlertsToTrigger] Ran into error sending an alert: %s", err.Error())
log.Printf("[watchdog][handleAlertsToTrigger] Failed to send an alert for service=%s: %s", service.Name, err.Error())
} else {
alert.Triggered = true
}
@ -73,18 +73,20 @@ func handleAlertsToResolve(service *core.Service, result *core.Result, cfg *conf
if !alert.Enabled || !alert.Triggered || alert.SuccessThreshold > service.NumberOfSuccessesInARow {
continue
}
// Even if the alert provider returns an error, we still set the alert's Triggered variable to false.
// Further explanation can be found on Alert's Triggered field.
alert.Triggered = false
if !alert.SendOnResolved {
continue
}
alertProvider := config.GetAlertingProviderByAlertType(cfg, alert.Type)
if alertProvider != nil && alertProvider.IsValid() {
log.Printf("[watchdog][handleAlertsToResolve] Sending %s alert because alert with description='%s' has been RESOLVED", alert.Type, alert.Description)
log.Printf("[watchdog][handleAlertsToResolve] Sending %s alert because alert for service=%s with description='%s' has been RESOLVED", alert.Type, service.Name, alert.Description)
customAlertProvider := alertProvider.ToCustomAlertProvider(service, alert, result, true)
// TODO: retry on error
_, err := customAlertProvider.Send(service.Name, alert.Description, true)
if err != nil {
log.Printf("[watchdog][handleAlertsToResolve] Ran into error sending an alert: %s", err.Error())
log.Printf("[watchdog][handleAlertsToResolve] Failed to send an alert for service=%s: %s", service.Name, err.Error())
} else {
if alert.Type == core.PagerDutyAlert {
alert.ResolveKey = ""

349
watchdog/alerting_test.go
View file

@ -39,103 +39,23 @@ func TestHandleAlerting(t *testing.T) {
},
}
if service.NumberOfFailuresInARow != 0 {
t.Fatal("service.NumberOfFailuresInARow should've started at 0, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've started at 0, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't start triggered")
}
verify(t, service, 0, 0, false, "The alert shouldn't start triggered")
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 1 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 0 to 1, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't have triggered")
}
verify(t, service, 1, 0, false, "The alert shouldn't have triggered")
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 2 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 1 to 2, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if !service.Alerts[0].Triggered {
t.Fatal("The alert should've triggered")
}
verify(t, service, 2, 0, true, "The alert should've triggered")
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 3 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 2 to 3, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if !service.Alerts[0].Triggered {
t.Fatal("The alert should still show as triggered")
}
verify(t, service, 3, 0, true, "The alert should still be triggered")
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 4 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 3 to 4, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if !service.Alerts[0].Triggered {
t.Fatal("The alert should still show as triggered")
}
verify(t, service, 4, 0, true, "The alert should still be triggered")
HandleAlerting(service, &core.Result{Success: true})
if service.NumberOfFailuresInARow != 0 {
t.Fatal("service.NumberOfFailuresInARow should've reset to 0, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 1 {
t.Fatal("service.NumberOfSuccessesInARow should've increased from 0 to 1, got", service.NumberOfSuccessesInARow)
}
if !service.Alerts[0].Triggered {
t.Fatal("The alert should still be triggered (because service.Alerts[0].SuccessThreshold is 3)")
}
verify(t, service, 0, 1, true, "The alert should still be triggered (because service.Alerts[0].SuccessThreshold is 3)")
HandleAlerting(service, &core.Result{Success: true})
if service.NumberOfFailuresInARow != 0 {
t.Fatal("service.NumberOfFailuresInARow should've stayed at 0, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 2 {
t.Fatal("service.NumberOfSuccessesInARow should've increased from 1 to 2, got", service.NumberOfSuccessesInARow)
}
if !service.Alerts[0].Triggered {
t.Fatal("The alert should still be triggered")
}
verify(t, service, 0, 2, true, "The alert should still be triggered (because service.Alerts[0].SuccessThreshold is 3)")
HandleAlerting(service, &core.Result{Success: true})
if service.NumberOfFailuresInARow != 0 {
t.Fatal("service.NumberOfFailuresInARow should've stayed at 0, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 3 {
t.Fatal("service.NumberOfSuccessesInARow should've increased from 2 to 3, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert should not be triggered")
}
verify(t, service, 0, 3, false, "The alert should've been resolved")
HandleAlerting(service, &core.Result{Success: true})
if service.NumberOfFailuresInARow != 0 {
t.Fatal("service.NumberOfFailuresInARow should've stayed at 0, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 4 {
t.Fatal("service.NumberOfSuccessesInARow should've increased from 3 to 4, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert should no longer be triggered")
}
verify(t, service, 0, 4, false, "The alert should no longer be triggered")
}
func TestHandleAlertingWhenAlertingConfigIsNil(t *testing.T) {
@ -172,92 +92,11 @@ func TestHandleAlertingWithBadAlertProvider(t *testing.T) {
},
}
if service.NumberOfFailuresInARow != 0 {
t.Fatal("service.NumberOfFailuresInARow should've started at 0, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've started at 0, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't start triggered")
}
verify(t, service, 0, 0, false, "The alert shouldn't start triggered")
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 1 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 0 to 1, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't have triggered")
}
verify(t, service, 1, 0, false, "The alert shouldn't have triggered")
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 2 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 1 to 2, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't have triggered, because the provider wasn't configured properly")
}
}
func TestHandleAlertingWithoutSendingAlertOnResolve(t *testing.T) {
_ = os.Setenv("MOCK_ALERT_PROVIDER", "true")
defer os.Clearenv()
cfg := &config.Config{
Alerting: &alerting.Config{},
}
config.Set(cfg)
service := &core.Service{
URL: "http://example.com",
Alerts: []*core.Alert{
{
Type: core.CustomAlert,
Enabled: true,
FailureThreshold: 1,
SuccessThreshold: 1,
SendOnResolved: false,
Triggered: false,
},
},
}
if service.NumberOfFailuresInARow != 0 {
t.Fatal("service.NumberOfFailuresInARow should've started at 0, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've started at 0, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't start triggered")
}
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 1 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 0 to 1, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't have triggered")
}
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 2 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 1 to 2, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't have triggered, because the provider wasn't configured properly")
}
verify(t, service, 2, 0, false, "The alert shouldn't have triggered, because the provider wasn't configured properly")
}
func TestHandleAlertingWhenTriggeredAlertIsAlmostResolvedButServiceStartFailingAgain(t *testing.T) {
@ -291,15 +130,7 @@ func TestHandleAlertingWhenTriggeredAlertIsAlmostResolvedButServiceStartFailingA
// This test simulate an alert that was already triggered
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 2 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 1 to 2, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if !service.Alerts[0].Triggered {
t.Fatal("The alert was already triggered at the beginning of this test")
}
verify(t, service, 2, 0, true, "The alert was already triggered at the beginning of this test")
}
func TestHandleAlertingWhenTriggeredAlertIsResolvedButSendOnResolvedIsFalse(t *testing.T) {
@ -332,15 +163,7 @@ func TestHandleAlertingWhenTriggeredAlertIsResolvedButSendOnResolvedIsFalse(t *t
}
HandleAlerting(service, &core.Result{Success: true})
if service.NumberOfFailuresInARow != 0 {
t.Fatal("service.NumberOfFailuresInARow should've decreased from 1 to 0, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 1 {
t.Fatal("service.NumberOfSuccessesInARow should've increased from 0 to 1, got", service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't be triggered anymore")
}
verify(t, service, 0, 1, false, "The alert should've been resolved")
}
func TestHandleAlertingWhenTriggeredAlertIsResolvedPagerDuty(t *testing.T) {
@ -372,24 +195,138 @@ func TestHandleAlertingWhenTriggeredAlertIsResolvedPagerDuty(t *testing.T) {
}
HandleAlerting(service, &core.Result{Success: false})
if service.NumberOfFailuresInARow != 1 {
t.Fatal("service.NumberOfFailuresInARow should've increased from 0 to 1, got", service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != 0 {
t.Fatal("service.NumberOfSuccessesInARow should've stayed at 0, got", service.NumberOfSuccessesInARow)
}
if !service.Alerts[0].Triggered {
t.Fatal("The alert should've been triggered")
}
verify(t, service, 1, 0, true, "")
HandleAlerting(service, &core.Result{Success: true})
if service.NumberOfFailuresInARow != 0 {
t.Fatal("service.NumberOfFailuresInARow should've decreased from 1 to 0, got", service.NumberOfFailuresInARow)
verify(t, service, 0, 1, false, "The alert should've been resolved")
}
func TestHandleAlertingWithProviderThatReturnsAnError(t *testing.T) {
_ = os.Setenv("MOCK_ALERT_PROVIDER", "true")
defer os.Clearenv()
cfg := &config.Config{
Debug: true,
Alerting: &alerting.Config{
Custom: &custom.AlertProvider{
URL: "https://twinnation.org/health",
Method: "GET",
},
},
}
if service.NumberOfSuccessesInARow != 1 {
t.Fatal("service.NumberOfSuccessesInARow should've increased from 0 to 1, got", service.NumberOfSuccessesInARow)
config.Set(cfg)
service := &core.Service{
URL: "http://example.com",
Alerts: []*core.Alert{
{
Type: core.CustomAlert,
Enabled: true,
FailureThreshold: 2,
SuccessThreshold: 2,
SendOnResolved: true,
Triggered: false,
},
},
}
if service.Alerts[0].Triggered {
t.Fatal("The alert shouldn't be triggered anymore")
_ = os.Setenv("MOCK_ALERT_PROVIDER_ERROR", "true")
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 1, 0, false, "")
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 2, 0, false, "The alert should have failed to trigger, because the alert provider is returning an error")
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 3, 0, false, "The alert should still not be triggered, because the alert provider is still returning an error")
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 4, 0, false, "The alert should still not be triggered, because the alert provider is still returning an error")
_ = os.Setenv("MOCK_ALERT_PROVIDER_ERROR", "false")
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 5, 0, true, "The alert should've been triggered because the alert provider is no longer returning an error")
HandleAlerting(service, &core.Result{Success: true})
verify(t, service, 0, 1, true, "The alert should've still been triggered")
_ = os.Setenv("MOCK_ALERT_PROVIDER_ERROR", "true")
HandleAlerting(service, &core.Result{Success: true})
verify(t, service, 0, 2, false, "The alert should've been resolved DESPITE THE ALERT PROVIDER RETURNING AN ERROR. See Alert.Triggered for further explanation.")
_ = os.Setenv("MOCK_ALERT_PROVIDER_ERROR", "false")
// Make sure that everything's working as expected after a rough patch
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 1, 0, false, "")
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 2, 0, true, "The alert should have triggered")
HandleAlerting(service, &core.Result{Success: true})
verify(t, service, 0, 1, true, "The alert should still be triggered")
HandleAlerting(service, &core.Result{Success: true})
verify(t, service, 0, 2, false, "The alert should have been resolved")
}
func TestHandleAlertingWithProviderThatOnlyReturnsErrorOnResolve(t *testing.T) {
_ = os.Setenv("MOCK_ALERT_PROVIDER", "true")
defer os.Clearenv()
cfg := &config.Config{
Debug: true,
Alerting: &alerting.Config{
Custom: &custom.AlertProvider{
URL: "https://twinnation.org/health",
Method: "GET",
},
},
}
config.Set(cfg)
service := &core.Service{
URL: "http://example.com",
Alerts: []*core.Alert{
{
Type: core.CustomAlert,
Enabled: true,
FailureThreshold: 1,
SuccessThreshold: 1,
SendOnResolved: true,
Triggered: false,
},
},
}
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 1, 0, true, "")
_ = os.Setenv("MOCK_ALERT_PROVIDER_ERROR", "true")
HandleAlerting(service, &core.Result{Success: true})
verify(t, service, 0, 1, false, "")
_ = os.Setenv("MOCK_ALERT_PROVIDER_ERROR", "false")
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 1, 0, true, "")
_ = os.Setenv("MOCK_ALERT_PROVIDER_ERROR", "true")
HandleAlerting(service, &core.Result{Success: true})
verify(t, service, 0, 1, true, "")
_ = os.Setenv("MOCK_ALERT_PROVIDER_ERROR", "false")
// Make sure that everything's working as expected after a rough patch
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 1, 0, false, "")
HandleAlerting(service, &core.Result{Success: false})
verify(t, service, 2, 0, true, "The alert should have triggered")
HandleAlerting(service, &core.Result{Success: true})
verify(t, service, 0, 1, true, "The alert should still be triggered")
HandleAlerting(service, &core.Result{Success: true})
verify(t, service, 0, 2, false, "The alert should have been resolved")
}
func verify(t *testing.T, service *core.Service, expectedNumberOfFailuresInARow, expectedNumberOfSuccessInARow int, expectedTriggered bool, expectedTriggeredReason string) {
if service.NumberOfFailuresInARow != expectedNumberOfFailuresInARow {
t.Fatalf("service.NumberOfFailuresInARow should've been %d, got %d", expectedNumberOfFailuresInARow, service.NumberOfFailuresInARow)
}
if service.NumberOfSuccessesInARow != expectedNumberOfSuccessInARow {
t.Fatalf("service.NumberOfSuccessesInARow should've been %d, got %d", expectedNumberOfSuccessInARow, service.NumberOfSuccessesInARow)
}
if service.Alerts[0].Triggered != expectedTriggered {
if len(expectedTriggeredReason) != 0 {
t.Fatal(expectedTriggeredReason)
} else {
if expectedTriggered {
t.Fatal("The alert should've been triggered")
} else {
t.Fatal("The alert shouldn't have been triggered")
}
}
}
}