Merge pull request #113 from TwinProduction/default-provider-alert

Implement default provider alert

README.md

@@ -250,6 +250,11 @@ ignored.
 | `alerting.custom.insecure`               | Whether to skip verifying the server's certificate chain and host name        | `false`        |
 | `alerting.custom.body`                   | Custom alerting request body.                                                 | `""`           |
 | `alerting.custom.headers`                | Custom alerting request headers                                               | `{}`           |
+| `alerting.*.default-alert.enabled`            | Whether to enable the alert                                                   | N/A       |
+| `alerting.*.default-alert.failure-threshold`  | Number of failures in a row needed before triggering the alert                | N/A       |
+| `alerting.*.default-alert.success-threshold`  | Number of successes in a row before an ongoing incident is marked as resolved | N/A       |
+| `alerting.*.default-alert.send-on-resolved`   | Whether to send a notification once a triggered alert is marked as resolved   | N/A       |
+| `alerting.*.default-alert.description`        | Description of the alert. Will be included in the alert sent                  | N/A       |
 
 
 #### Configuring Slack alerts
@@ -503,6 +508,59 @@ As a result, the `[ALERT_TRIGGERED_OR_RESOLVED]` in the body of first example of
 `partial_outage` when an alert is triggered and `operational` when an alert is resolved.
 
 
+#### Setting a default provider alert
+
+While you can specify the alert configuration directly in the service definition, it's tedious and may lead to a very
+long configuration file.
+
+To avoid such problem, you can use the `default-alert` parameter present in each provider configuration:
+```yaml
+alerting:
+  slack: 
+    webhook-url: "https://hooks.slack.com/services/**********/**********/**********"
+    default-alert:
+      enabled: true
+      description: "healthcheck failed"
+      send-on-resolved: true
+      failure-threshold: 5
+      success-threshold: 5
+```
+
+As a result, your service configuration looks a lot tidier:
+```yaml
+services:
+  - name: example
+    url: "https://example.org"
+    alerts:
+      - type: slack
+    conditions:
+      - "[STATUS] == 200"
+
+  - name: other-example
+    url: "https://example.com"
+    alerts:
+      - type: slack
+    conditions:
+      - "[STATUS] == 200"
+```
+
+It also allows you to do things like this:
+```yaml
+services:
+  - name: twinnation
+    url: "https://twinnation.org/health"
+    alerts:
+      - type: slack
+        failure-threshold: 5
+      - type: slack
+        failure-threshold: 10
+      - type: slack
+        failure-threshold: 15
+    conditions:
+      - "[STATUS] == 200"
+```
+
+
 ### Kubernetes (ALPHA)
 
 > **WARNING**: This feature is in ALPHA. This means that it is very likely to change in the near future, which means that

alerting/provider/custom/custom.go

@@ -22,6 +22,9 @@ type AlertProvider struct {
 	Body         string                       `yaml:"body,omitempty"`
 	Headers      map[string]string            `yaml:"headers,omitempty"`
 	Placeholders map[string]map[string]string `yaml:"placeholders,omitempty"`
+
+	// DefaultAlert is the default alert configuration to use for services with an alert of the appropriate type
+	DefaultAlert *core.Alert `yaml:"default-alert"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -112,3 +115,8 @@ func (provider *AlertProvider) Send(serviceName, alertDescription string, resolv
 	}
 	return ioutil.ReadAll(response.Body)
 }
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *core.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/discord/discord.go

@@ -11,6 +11,9 @@ import (
 // AlertProvider is the configuration necessary for sending an alert using Discord
 type AlertProvider struct {
 	WebhookURL string `yaml:"webhook-url"`
+
+	// DefaultAlert is the default alert configuration to use for services with an alert of the appropriate type
+	DefaultAlert *core.Alert `yaml:"default-alert"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -57,7 +60,12 @@ func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, aler
       ]
     }
   ]
-}`, message, alert.Description, colorCode, results),
+}`, message, alert.GetDescription(), colorCode, results),
 		Headers: map[string]string{"Content-Type": "application/json"},
 	}
 }
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *core.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/mattermost/mattermost.go

@@ -12,6 +12,9 @@ import (
 type AlertProvider struct {
 	WebhookURL string `yaml:"webhook-url"`
 	Insecure   bool   `yaml:"insecure,omitempty"`
+
+	// DefaultAlert is the default alert configuration to use for services with an alert of the appropriate type
+	DefaultAlert *core.Alert `yaml:"default-alert"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -69,7 +72,12 @@ func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, aler
       ]
     }
   ]
-}`, message, message, alert.Description, color, service.URL, results),
+}`, message, message, alert.GetDescription(), color, service.URL, results),
 		Headers: map[string]string{"Content-Type": "application/json"},
 	}
 }
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *core.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/messagebird/messagebird.go

@@ -17,6 +17,9 @@ type AlertProvider struct {
 	AccessKey  string `yaml:"access-key"`
 	Originator string `yaml:"originator"`
 	Recipients string `yaml:"recipients"`
+
+	// DefaultAlert is the default alert configuration to use for services with an alert of the appropriate type
+	DefaultAlert *core.Alert `yaml:"default-alert"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -29,9 +32,9 @@ func (provider *AlertProvider) IsValid() bool {
 func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, alert *core.Alert, _ *core.Result, resolved bool) *custom.AlertProvider {
 	var message string
 	if resolved {
-		message = fmt.Sprintf("RESOLVED: %s - %s", service.Name, alert.Description)
+		message = fmt.Sprintf("RESOLVED: %s - %s", service.Name, alert.GetDescription())
 	} else {
-		message = fmt.Sprintf("TRIGGERED: %s - %s", service.Name, alert.Description)
+		message = fmt.Sprintf("TRIGGERED: %s - %s", service.Name, alert.GetDescription())
 	}
 
 	return &custom.AlertProvider{
@@ -48,3 +51,8 @@ func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, aler
 		},
 	}
 }
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *core.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/pagerduty/pagerduty.go

@@ -11,6 +11,9 @@ import (
 // AlertProvider is the configuration necessary for sending an alert using PagerDuty
 type AlertProvider struct {
 	IntegrationKey string `yaml:"integration-key"`
+
+	// DefaultAlert is the default alert configuration to use for services with an alert of the appropriate type
+	DefaultAlert *core.Alert `yaml:"default-alert"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -24,11 +27,11 @@ func (provider *AlertProvider) IsValid() bool {
 func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, alert *core.Alert, _ *core.Result, resolved bool) *custom.AlertProvider {
 	var message, eventAction, resolveKey string
 	if resolved {
-		message = fmt.Sprintf("RESOLVED: %s - %s", service.Name, alert.Description)
+		message = fmt.Sprintf("RESOLVED: %s - %s", service.Name, alert.GetDescription())
 		eventAction = "resolve"
 		resolveKey = alert.ResolveKey
 	} else {
-		message = fmt.Sprintf("TRIGGERED: %s - %s", service.Name, alert.Description)
+		message = fmt.Sprintf("TRIGGERED: %s - %s", service.Name, alert.GetDescription())
 		eventAction = "trigger"
 		resolveKey = ""
 	}
@@ -50,3 +53,8 @@ func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, aler
 		},
 	}
 }
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *core.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/provider.go

@@ -19,6 +19,31 @@ type AlertProvider interface {
 
 	// ToCustomAlertProvider converts the provider into a custom.AlertProvider
 	ToCustomAlertProvider(service *core.Service, alert *core.Alert, result *core.Result, resolved bool) *custom.AlertProvider
+
+	// GetDefaultAlert returns the provider's default alert configuration
+	GetDefaultAlert() *core.Alert
+}
+
+// ParseWithDefaultAlert parses a service alert by using the provider's default alert as a baseline
+func ParseWithDefaultAlert(providerDefaultAlert, serviceAlert *core.Alert) {
+	if providerDefaultAlert == nil || serviceAlert == nil {
+		return
+	}
+	if serviceAlert.Enabled == nil {
+		serviceAlert.Enabled = providerDefaultAlert.Enabled
+	}
+	if serviceAlert.SendOnResolved == nil {
+		serviceAlert.SendOnResolved = providerDefaultAlert.SendOnResolved
+	}
+	if serviceAlert.Description == nil {
+		serviceAlert.Description = providerDefaultAlert.Description
+	}
+	if serviceAlert.FailureThreshold == 0 {
+		serviceAlert.FailureThreshold = providerDefaultAlert.FailureThreshold
+	}
+	if serviceAlert.SuccessThreshold == 0 {
+		serviceAlert.SuccessThreshold = providerDefaultAlert.SuccessThreshold
+	}
 }
 
 var (

alerting/provider/provider_test.go

@@ -0,0 +1,153 @@
+package provider
+
+import (
+	"testing"
+
+	"github.com/TwinProduction/gatus/core"
+)
+
+func TestParseWithDefaultAlert(t *testing.T) {
+	type Scenario struct {
+		Name                                            string
+		DefaultAlert, ServiceAlert, ExpectedOutputAlert *core.Alert
+	}
+	enabled := true
+	disabled := false
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []Scenario{
+		{
+			Name: "service-alert-type-only",
+			DefaultAlert: &core.Alert{
+				Enabled:          &enabled,
+				SendOnResolved:   &enabled,
+				Description:      &firstDescription,
+				FailureThreshold: 5,
+				SuccessThreshold: 10,
+			},
+			ServiceAlert: &core.Alert{
+				Type: core.DiscordAlert,
+			},
+			ExpectedOutputAlert: &core.Alert{
+				Type:             core.DiscordAlert,
+				Enabled:          &enabled,
+				SendOnResolved:   &enabled,
+				Description:      &firstDescription,
+				FailureThreshold: 5,
+				SuccessThreshold: 10,
+			},
+		},
+		{
+			Name: "service-alert-overwrites-default-alert",
+			DefaultAlert: &core.Alert{
+				Enabled:          &disabled,
+				SendOnResolved:   &disabled,
+				Description:      &firstDescription,
+				FailureThreshold: 5,
+				SuccessThreshold: 10,
+			},
+			ServiceAlert: &core.Alert{
+				Type:             core.TelegramAlert,
+				Enabled:          &enabled,
+				SendOnResolved:   &enabled,
+				Description:      &secondDescription,
+				FailureThreshold: 6,
+				SuccessThreshold: 11,
+			},
+			ExpectedOutputAlert: &core.Alert{
+				Type:             core.TelegramAlert,
+				Enabled:          &enabled,
+				SendOnResolved:   &enabled,
+				Description:      &secondDescription,
+				FailureThreshold: 6,
+				SuccessThreshold: 11,
+			},
+		},
+		{
+			Name: "service-alert-partially-overwrites-default-alert",
+			DefaultAlert: &core.Alert{
+				Enabled:          &enabled,
+				SendOnResolved:   &enabled,
+				Description:      &firstDescription,
+				FailureThreshold: 5,
+				SuccessThreshold: 10,
+			},
+			ServiceAlert: &core.Alert{
+				Type:             core.DiscordAlert,
+				Enabled:          nil,
+				SendOnResolved:   nil,
+				FailureThreshold: 6,
+				SuccessThreshold: 11,
+			},
+			ExpectedOutputAlert: &core.Alert{
+				Type:             core.DiscordAlert,
+				Enabled:          &enabled,
+				SendOnResolved:   &enabled,
+				Description:      &firstDescription,
+				FailureThreshold: 6,
+				SuccessThreshold: 11,
+			},
+		},
+		{
+			Name: "default-alert-type-should-be-ignored",
+			DefaultAlert: &core.Alert{
+				Type:             core.TelegramAlert,
+				Enabled:          &enabled,
+				SendOnResolved:   &enabled,
+				Description:      &firstDescription,
+				FailureThreshold: 5,
+				SuccessThreshold: 10,
+			},
+			ServiceAlert: &core.Alert{
+				Type: core.DiscordAlert,
+			},
+			ExpectedOutputAlert: &core.Alert{
+				Type:             core.DiscordAlert,
+				Enabled:          &enabled,
+				SendOnResolved:   &enabled,
+				Description:      &firstDescription,
+				FailureThreshold: 5,
+				SuccessThreshold: 10,
+			},
+		},
+		{
+			Name: "no-default-alert",
+			DefaultAlert: &core.Alert{
+				Type:             core.DiscordAlert,
+				Enabled:          nil,
+				SendOnResolved:   nil,
+				Description:      &firstDescription,
+				FailureThreshold: 2,
+				SuccessThreshold: 5,
+			},
+			ServiceAlert:        nil,
+			ExpectedOutputAlert: nil,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			ParseWithDefaultAlert(scenario.DefaultAlert, scenario.ServiceAlert)
+			if scenario.ExpectedOutputAlert == nil {
+				if scenario.ServiceAlert != nil {
+					t.Fail()
+				}
+				return
+			}
+			if scenario.ServiceAlert.IsEnabled() != scenario.ExpectedOutputAlert.IsEnabled() {
+				t.Errorf("expected ServiceAlert.IsEnabled() to be %v, got %v", scenario.ExpectedOutputAlert.IsEnabled(), scenario.ServiceAlert.IsEnabled())
+			}
+			if scenario.ServiceAlert.IsSendingOnResolved() != scenario.ExpectedOutputAlert.IsSendingOnResolved() {
+				t.Errorf("expected ServiceAlert.IsSendingOnResolved() to be %v, got %v", scenario.ExpectedOutputAlert.IsSendingOnResolved(), scenario.ServiceAlert.IsSendingOnResolved())
+			}
+			if scenario.ServiceAlert.GetDescription() != scenario.ExpectedOutputAlert.GetDescription() {
+				t.Errorf("expected ServiceAlert.GetDescription() to be %v, got %v", scenario.ExpectedOutputAlert.GetDescription(), scenario.ServiceAlert.GetDescription())
+			}
+			if scenario.ServiceAlert.FailureThreshold != scenario.ExpectedOutputAlert.FailureThreshold {
+				t.Errorf("expected ServiceAlert.FailureThreshold to be %v, got %v", scenario.ExpectedOutputAlert.FailureThreshold, scenario.ServiceAlert.FailureThreshold)
+			}
+			if scenario.ServiceAlert.SuccessThreshold != scenario.ExpectedOutputAlert.SuccessThreshold {
+				t.Errorf("expected ServiceAlert.SuccessThreshold to be %v, got %v", scenario.ExpectedOutputAlert.SuccessThreshold, scenario.ServiceAlert.SuccessThreshold)
+			}
+		})
+	}
+}

alerting/provider/slack/slack.go

@@ -11,6 +11,9 @@ import (
 // AlertProvider is the configuration necessary for sending an alert using Slack
 type AlertProvider struct {
 	WebhookURL string `yaml:"webhook-url"` // Slack webhook URL
+
+	// DefaultAlert is the default alert configuration to use for services with an alert of the appropriate type
+	DefaultAlert *core.Alert `yaml:"default-alert"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -57,7 +60,12 @@ func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, aler
       ]
     }
   ]
-}`, message, alert.Description, color, results),
+}`, message, alert.GetDescription(), color, results),
 		Headers: map[string]string{"Content-Type": "application/json"},
 	}
 }
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *core.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/telegram/telegram.go

@@ -12,6 +12,9 @@ import (
 type AlertProvider struct {
 	Token string `yaml:"token"`
 	ID    string `yaml:"id"`
+
+	// DefaultAlert is the default alert configuration to use for services with an alert of the appropriate type
+	DefaultAlert *core.Alert `yaml:"default-alert"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -37,8 +40,8 @@ func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, aler
 		results += fmt.Sprintf("%s - `%s`\\n", prefix, conditionResult.Condition)
 	}
 	var text string
-	if len(alert.Description) > 0 {
-		text = fmt.Sprintf("⛑ *Gatus* \\n%s \\n*Description* \\n_%s_  \\n\\n*Condition results*\\n%s", message, alert.Description, results)
+	if len(alert.GetDescription()) > 0 {
+		text = fmt.Sprintf("⛑ *Gatus* \\n%s \\n*Description* \\n_%s_  \\n\\n*Condition results*\\n%s", message, alert.GetDescription(), results)
 	} else {
 		text = fmt.Sprintf("⛑ *Gatus* \\n%s \\n*Condition results*\\n%s", message, results)
 	}
@@ -49,3 +52,8 @@ func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, aler
 		Headers: map[string]string{"Content-Type": "application/json"},
 	}
 }
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *core.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/telegram/telegram_test.go

@@ -46,7 +46,8 @@ func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
 
 func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
 	provider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "0123456789"}
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Service{}, &core.Alert{Description: "Healthcheck Successful"}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "UNSUCCESSFUL_CONDITION", Success: false}}}, false)
+	description := "Healthcheck Successful"
+	customAlertProvider := provider.ToCustomAlertProvider(&core.Service{}, &core.Alert{Description: &description}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "UNSUCCESSFUL_CONDITION", Success: false}}}, false)
 	if customAlertProvider == nil {
 		t.Fatal("customAlertProvider shouldn't have been nil")
 	}

alerting/provider/twilio/twilio.go

@@ -16,6 +16,9 @@ type AlertProvider struct {
 	Token string `yaml:"token"`
 	From  string `yaml:"from"`
 	To    string `yaml:"to"`
+
+	// DefaultAlert is the default alert configuration to use for services with an alert of the appropriate type
+	DefaultAlert *core.Alert `yaml:"default-alert"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -27,9 +30,9 @@ func (provider *AlertProvider) IsValid() bool {
 func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, alert *core.Alert, _ *core.Result, resolved bool) *custom.AlertProvider {
 	var message string
 	if resolved {
-		message = fmt.Sprintf("RESOLVED: %s - %s", service.Name, alert.Description)
+		message = fmt.Sprintf("RESOLVED: %s - %s", service.Name, alert.GetDescription())
 	} else {
-		message = fmt.Sprintf("TRIGGERED: %s - %s", service.Name, alert.Description)
+		message = fmt.Sprintf("TRIGGERED: %s - %s", service.Name, alert.GetDescription())
 	}
 	return &custom.AlertProvider{
 		URL:    fmt.Sprintf("https://api.twilio.com/2010-04-01/Accounts/%s/Messages.json", provider.SID),
@@ -45,3 +48,8 @@ func (provider *AlertProvider) ToCustomAlertProvider(service *core.Service, aler
 		},
 	}
 }
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *core.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/twilio/twilio_test.go

@@ -31,7 +31,8 @@ func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
 		From:  "3",
 		To:    "4",
 	}
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Service{Name: "service-name"}, &core.Alert{Description: "alert-description"}, &core.Result{}, true)
+	description := "alert-description"
+	customAlertProvider := provider.ToCustomAlertProvider(&core.Service{Name: "service-name"}, &core.Alert{Description: &description}, &core.Result{}, true)
 	if customAlertProvider == nil {
 		t.Fatal("customAlertProvider shouldn't have been nil")
 	}
@@ -56,7 +57,8 @@ func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
 		From:  "2",
 		To:    "1",
 	}
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Service{Name: "service-name"}, &core.Alert{Description: "alert-description"}, &core.Result{}, false)
+	description := "alert-description"
+	customAlertProvider := provider.ToCustomAlertProvider(&core.Service{Name: "service-name"}, &core.Alert{Description: &description}, &core.Result{}, false)
 	if customAlertProvider == nil {
 		t.Fatal("customAlertProvider shouldn't have been nil")
 	}

config/config.go

@@ -222,6 +222,10 @@ func validateSecurityConfig(config *Config) {
 	}
 }
 
+// validateAlertingConfig validates the alerting configuration
+// Note that the alerting configuration has to be validated before the service configuration, because the default alert
+// returned by provider.AlertProvider.GetDefaultAlert() must be parsed before core.Service.ValidateAndSetDefaults()
+// sets the default alert values when none are set.
 func validateAlertingConfig(config *Config) {
 	if config.Alerting == nil {
 		log.Printf("[config][validateAlertingConfig] Alerting is not configured")
@@ -242,6 +246,19 @@ func validateAlertingConfig(config *Config) {
 		alertProvider := GetAlertingProviderByAlertType(config, alertType)
 		if alertProvider != nil {
 			if alertProvider.IsValid() {
+				// Parse alerts with the provider's default alert
+				if alertProvider.GetDefaultAlert() != nil {
+					for _, service := range config.Services {
+						for alertIndex, alert := range service.Alerts {
+							if alertType == alert.Type {
+								if config.Debug {
+									log.Printf("[config][validateAlertingConfig] Parsing alert %d with provider's default alert for provider=%s in service=%s", alertIndex, alertType, service.Name)
+								}
+								provider.ParseWithDefaultAlert(alertProvider.GetDefaultAlert(), alert)
+							}
+						}
+					}
+				}
 				validProviders = append(validProviders, alertType)
 			} else {
 				log.Printf("[config][validateAlertingConfig] Ignoring provider=%s because configuration is invalid", alertType)

config/config_test.go

@@ -351,6 +351,8 @@ alerting:
     webhook-url: "http://example.org"
   pagerduty:
     integration-key: "00000000000000000000000000000000"
+  mattermost:
+    webhook-url: "http://example.com"
   messagebird:
     access-key: "1"
     originator: "31619191918"
@@ -358,6 +360,12 @@ alerting:
   telegram:
     token: 123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11
     id: 0123456789
+  twilio:
+    sid: "1234"
+    token: "5678"
+    from: "+1-234-567-8901"
+    to: "+1-234-567-8901"
+
 services:
   - name: twinnation
     url: https://twinnation.org/health
@@ -369,14 +377,196 @@ services:
         failure-threshold: 7
         success-threshold: 5
         description: "Healthcheck failed 7 times in a row"
+      - type: mattermost
+        enabled: true
       - type: messagebird
       - type: discord
         enabled: true
         failure-threshold: 10
       - type: telegram
         enabled: true
+      - type: twilio
+        enabled: true
+        failure-threshold: 12
+        success-threshold: 15
     conditions:
       - "[STATUS] == 200"
+`))
+	if err != nil {
+		t.Error("expected no error, got", err.Error())
+	}
+	if config == nil {
+		t.Fatal("Config shouldn't have been nil")
+	}
+	// Alerting providers
+	if config.Alerting == nil {
+		t.Fatal("config.Alerting shouldn't have been nil")
+	}
+	if config.Alerting.Slack == nil || !config.Alerting.Slack.IsValid() {
+		t.Fatal("Slack alerting config should've been valid")
+	}
+	// Services
+	if len(config.Services) != 1 {
+		t.Error("There should've been 1 service")
+	}
+	if config.Services[0].URL != "https://twinnation.org/health" {
+		t.Errorf("URL should have been %s", "https://twinnation.org/health")
+	}
+	if config.Services[0].Interval != 60*time.Second {
+		t.Errorf("Interval should have been %s, because it is the default value", 60*time.Second)
+	}
+	if len(config.Services[0].Alerts) != 7 {
+		t.Fatal("There should've been 7 alerts configured")
+	}
+
+	if config.Services[0].Alerts[0].Type != core.SlackAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.SlackAlert, config.Services[0].Alerts[0].Type)
+	}
+	if !config.Services[0].Alerts[0].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[0].FailureThreshold != 3 {
+		t.Errorf("The default failure threshold of the alert should've been %d, but it was %d", 3, config.Services[0].Alerts[0].FailureThreshold)
+	}
+	if config.Services[0].Alerts[0].SuccessThreshold != 2 {
+		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 2, config.Services[0].Alerts[0].SuccessThreshold)
+	}
+
+	if config.Services[0].Alerts[1].Type != core.PagerDutyAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.PagerDutyAlert, config.Services[0].Alerts[1].Type)
+	}
+	if config.Services[0].Alerts[1].GetDescription() != "Healthcheck failed 7 times in a row" {
+		t.Errorf("The description of the alert should've been %s, but it was %s", "Healthcheck failed 7 times in a row", config.Services[0].Alerts[1].GetDescription())
+	}
+	if config.Services[0].Alerts[1].FailureThreshold != 7 {
+		t.Errorf("The failure threshold of the alert should've been %d, but it was %d", 7, config.Services[0].Alerts[1].FailureThreshold)
+	}
+	if config.Services[0].Alerts[1].SuccessThreshold != 5 {
+		t.Errorf("The success threshold of the alert should've been %d, but it was %d", 5, config.Services[0].Alerts[1].SuccessThreshold)
+	}
+
+	if config.Services[0].Alerts[2].Type != core.MattermostAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.MattermostAlert, config.Services[0].Alerts[2].Type)
+	}
+	if !config.Services[0].Alerts[2].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[2].FailureThreshold != 3 {
+		t.Errorf("The default failure threshold of the alert should've been %d, but it was %d", 3, config.Services[0].Alerts[2].FailureThreshold)
+	}
+	if config.Services[0].Alerts[2].SuccessThreshold != 2 {
+		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 2, config.Services[0].Alerts[2].SuccessThreshold)
+	}
+
+	if config.Services[0].Alerts[3].Type != core.MessagebirdAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.MessagebirdAlert, config.Services[0].Alerts[3].Type)
+	}
+	if config.Services[0].Alerts[3].IsEnabled() {
+		t.Error("The alert should've been disabled")
+	}
+
+	if config.Services[0].Alerts[4].Type != core.DiscordAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.DiscordAlert, config.Services[0].Alerts[4].Type)
+	}
+	if !config.Services[0].Alerts[4].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[4].FailureThreshold != 10 {
+		t.Errorf("The failure threshold of the alert should've been %d, but it was %d", 10, config.Services[0].Alerts[4].FailureThreshold)
+	}
+	if config.Services[0].Alerts[4].SuccessThreshold != 2 {
+		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 2, config.Services[0].Alerts[4].SuccessThreshold)
+	}
+
+	if config.Services[0].Alerts[5].Type != core.TelegramAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.TelegramAlert, config.Services[0].Alerts[5].Type)
+	}
+	if !config.Services[0].Alerts[5].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[5].FailureThreshold != 3 {
+		t.Errorf("The default failure threshold of the alert should've been %d, but it was %d", 3, config.Services[0].Alerts[5].FailureThreshold)
+	}
+	if config.Services[0].Alerts[5].SuccessThreshold != 2 {
+		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 2, config.Services[0].Alerts[5].SuccessThreshold)
+	}
+
+	if config.Services[0].Alerts[6].Type != core.TwilioAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.TwilioAlert, config.Services[0].Alerts[6].Type)
+	}
+	if !config.Services[0].Alerts[6].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[6].FailureThreshold != 12 {
+		t.Errorf("The default failure threshold of the alert should've been %d, but it was %d", 12, config.Services[0].Alerts[6].FailureThreshold)
+	}
+	if config.Services[0].Alerts[6].SuccessThreshold != 15 {
+		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 15, config.Services[0].Alerts[6].SuccessThreshold)
+	}
+}
+
+func TestParseAndValidateConfigBytesWithAlertingAndDefaultAlert(t *testing.T) {
+	config, err := parseAndValidateConfigBytes([]byte(`
+debug: true
+
+alerting:
+  slack:
+    webhook-url: "http://example.com"
+    default-alert:
+      enabled: true
+  discord:
+    webhook-url: "http://example.org"
+    default-alert:
+      enabled: true
+      failure-threshold: 10
+      success-threshold: 1
+  pagerduty:
+    integration-key: "00000000000000000000000000000000"
+    default-alert:
+      enabled: true
+      description: default description
+      failure-threshold: 7
+      success-threshold: 5
+  mattermost:
+    webhook-url: "http://example.com"
+    default-alert:
+      enabled: true
+  messagebird:
+    access-key: "1"
+    originator: "31619191918"
+    recipients: "31619191919"
+    default-alert:
+      enabled: false
+      send-on-resolved: true
+  telegram:
+    token: 123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11
+    id: 0123456789
+    default-alert:
+      enabled: true
+  twilio:
+    sid: "1234"
+    token: "5678"
+    from: "+1-234-567-8901"
+    to: "+1-234-567-8901"
+    default-alert:
+      enabled: true
+      failure-threshold: 12
+      success-threshold: 15
+
+services:
+ - name: twinnation
+   url: https://twinnation.org/health
+   alerts:
+     - type: slack
+     - type: pagerduty
+     - type: mattermost
+     - type: messagebird
+     - type: discord
+       success-threshold: 2 # test service alert override
+     - type: telegram
+     - type: twilio
+   conditions:
+     - "[STATUS] == 200"
 `))
 	if err != nil {
 		t.Error("expected no error, got", err.Error())
@@ -394,19 +584,36 @@ services:
 	if config.Alerting.Slack == nil || !config.Alerting.Slack.IsValid() {
 		t.Fatal("Slack alerting config should've been valid")
 	}
+	if config.Alerting.Slack.GetDefaultAlert() == nil {
+		t.Fatal("Slack.GetDefaultAlert() shouldn't have returned nil")
+	}
 	if config.Alerting.Slack.WebhookURL != "http://example.com" {
 		t.Errorf("Slack webhook should've been %s, but was %s", "http://example.com", config.Alerting.Slack.WebhookURL)
 	}
+
 	if config.Alerting.PagerDuty == nil || !config.Alerting.PagerDuty.IsValid() {
 		t.Fatal("PagerDuty alerting config should've been valid")
 	}
+	if config.Alerting.PagerDuty.GetDefaultAlert() == nil {
+		t.Fatal("PagerDuty.GetDefaultAlert() shouldn't have returned nil")
+	}
 	if config.Alerting.PagerDuty.IntegrationKey != "00000000000000000000000000000000" {
 		t.Errorf("PagerDuty integration key should've been %s, but was %s", "00000000000000000000000000000000", config.Alerting.PagerDuty.IntegrationKey)
 	}
 
+	if config.Alerting.Mattermost == nil || !config.Alerting.Mattermost.IsValid() {
+		t.Fatal("Mattermost alerting config should've been valid")
+	}
+	if config.Alerting.Mattermost.GetDefaultAlert() == nil {
+		t.Fatal("Mattermost.GetDefaultAlert() shouldn't have returned nil")
+	}
+
 	if config.Alerting.Messagebird == nil || !config.Alerting.Messagebird.IsValid() {
 		t.Fatal("Messagebird alerting config should've been valid")
 	}
+	if config.Alerting.Messagebird.GetDefaultAlert() == nil {
+		t.Fatal("Messagebird.GetDefaultAlert() shouldn't have returned nil")
+	}
 	if config.Alerting.Messagebird.AccessKey != "1" {
 		t.Errorf("Messagebird access key should've been %s, but was %s", "1", config.Alerting.Messagebird.AccessKey)
 	}
@@ -420,18 +627,34 @@ services:
 	if config.Alerting.Discord == nil || !config.Alerting.Discord.IsValid() {
 		t.Fatal("Discord alerting config should've been valid")
 	}
+	if config.Alerting.Discord.GetDefaultAlert() == nil {
+		t.Fatal("Discord.GetDefaultAlert() shouldn't have returned nil")
+	}
 	if config.Alerting.Discord.WebhookURL != "http://example.org" {
 		t.Errorf("Discord webhook should've been %s, but was %s", "http://example.org", config.Alerting.Discord.WebhookURL)
 	}
+	if GetAlertingProviderByAlertType(config, core.DiscordAlert) != config.Alerting.Discord {
+		t.Error("expected discord configuration")
+	}
 
+	if config.Alerting.Telegram == nil || !config.Alerting.Telegram.IsValid() {
+		t.Fatal("Telegram alerting config should've been valid")
+	}
+	if config.Alerting.Telegram.GetDefaultAlert() == nil {
+		t.Fatal("Telegram.GetDefaultAlert() shouldn't have returned nil")
+	}
 	if config.Alerting.Telegram.Token != "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11" {
 		t.Errorf("Telegram token should've been %s, but was %s", "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", config.Alerting.Telegram.Token)
 	}
 	if config.Alerting.Telegram.ID != "0123456789" {
 		t.Errorf("Telegram ID should've been %s, but was %s", "012345689", config.Alerting.Telegram.ID)
 	}
-	if GetAlertingProviderByAlertType(config, core.DiscordAlert) != config.Alerting.Discord {
-		t.Error("expected discord configuration")
+
+	if config.Alerting.Twilio == nil || !config.Alerting.Twilio.IsValid() {
+		t.Fatal("Twilio alerting config should've been valid")
+	}
+	if config.Alerting.Twilio.GetDefaultAlert() == nil {
+		t.Fatal("Twilio.GetDefaultAlert() shouldn't have returned nil")
 	}
 	// Services
 	if len(config.Services) != 1 {
@@ -443,14 +666,14 @@ services:
 	if config.Services[0].Interval != 60*time.Second {
 		t.Errorf("Interval should have been %s, because it is the default value", 60*time.Second)
 	}
-	if len(config.Services[0].Alerts) != 5 {
-		t.Fatal("There should've been 5 alerts configured")
+	if len(config.Services[0].Alerts) != 7 {
+		t.Fatal("There should've been 7 alerts configured")
 	}
 
 	if config.Services[0].Alerts[0].Type != core.SlackAlert {
 		t.Errorf("The type of the alert should've been %s, but it was %s", core.SlackAlert, config.Services[0].Alerts[0].Type)
 	}
-	if !config.Services[0].Alerts[0].Enabled {
+	if !config.Services[0].Alerts[0].IsEnabled() {
 		t.Error("The alert should've been enabled")
 	}
 	if config.Services[0].Alerts[0].FailureThreshold != 3 {
@@ -463,28 +686,155 @@ services:
 	if config.Services[0].Alerts[1].Type != core.PagerDutyAlert {
 		t.Errorf("The type of the alert should've been %s, but it was %s", core.PagerDutyAlert, config.Services[0].Alerts[1].Type)
 	}
-	if config.Services[0].Alerts[1].Description != "Healthcheck failed 7 times in a row" {
-		t.Errorf("The description of the alert should've been %s, but it was %s", "Healthcheck failed 7 times in a row", config.Services[0].Alerts[1].Description)
+	if config.Services[0].Alerts[1].GetDescription() != "default description" {
+		t.Errorf("The description of the alert should've been %s, but it was %s", "default description", config.Services[0].Alerts[1].GetDescription())
+	}
+	if config.Services[0].Alerts[1].FailureThreshold != 7 {
+		t.Errorf("The failure threshold of the alert should've been %d, but it was %d", 7, config.Services[0].Alerts[1].FailureThreshold)
 	}
 	if config.Services[0].Alerts[1].SuccessThreshold != 5 {
 		t.Errorf("The success threshold of the alert should've been %d, but it was %d", 5, config.Services[0].Alerts[1].SuccessThreshold)
 	}
 
-	if config.Services[0].Alerts[2].Type != core.MessagebirdAlert {
-		t.Errorf("The type of the alert should've been %s, but it was %s", core.MessagebirdAlert, config.Services[0].Alerts[2].Type)
+	if config.Services[0].Alerts[2].Type != core.MattermostAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.MattermostAlert, config.Services[0].Alerts[2].Type)
 	}
-	if config.Services[0].Alerts[2].Enabled {
-		t.Error("The alert should've been disabled")
+	if !config.Services[0].Alerts[2].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[2].FailureThreshold != 3 {
+		t.Errorf("The default failure threshold of the alert should've been %d, but it was %d", 3, config.Services[0].Alerts[2].FailureThreshold)
+	}
+	if config.Services[0].Alerts[2].SuccessThreshold != 2 {
+		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 2, config.Services[0].Alerts[2].SuccessThreshold)
 	}
 
-	if config.Services[0].Alerts[3].Type != core.DiscordAlert {
-		t.Errorf("The type of the alert should've been %s, but it was %s", core.DiscordAlert, config.Services[0].Alerts[3].Type)
+	if config.Services[0].Alerts[3].Type != core.MessagebirdAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.MessagebirdAlert, config.Services[0].Alerts[3].Type)
 	}
-	if config.Services[0].Alerts[3].FailureThreshold != 10 {
-		t.Errorf("The failure threshold of the alert should've been %d, but it was %d", 10, config.Services[0].Alerts[3].FailureThreshold)
+	if config.Services[0].Alerts[3].IsEnabled() {
+		t.Error("The alert should've been disabled")
 	}
-	if config.Services[0].Alerts[3].SuccessThreshold != 2 {
-		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 2, config.Services[0].Alerts[3].SuccessThreshold)
+	if !config.Services[0].Alerts[3].IsSendingOnResolved() {
+		t.Error("The alert should be sending on resolve")
+	}
+
+	if config.Services[0].Alerts[4].Type != core.DiscordAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.DiscordAlert, config.Services[0].Alerts[4].Type)
+	}
+	if !config.Services[0].Alerts[4].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[4].FailureThreshold != 10 {
+		t.Errorf("The failure threshold of the alert should've been %d, but it was %d", 10, config.Services[0].Alerts[4].FailureThreshold)
+	}
+	if config.Services[0].Alerts[4].SuccessThreshold != 2 {
+		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 2, config.Services[0].Alerts[4].SuccessThreshold)
+	}
+
+	if config.Services[0].Alerts[5].Type != core.TelegramAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.TelegramAlert, config.Services[0].Alerts[5].Type)
+	}
+	if !config.Services[0].Alerts[5].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[5].FailureThreshold != 3 {
+		t.Errorf("The default failure threshold of the alert should've been %d, but it was %d", 3, config.Services[0].Alerts[5].FailureThreshold)
+	}
+	if config.Services[0].Alerts[5].SuccessThreshold != 2 {
+		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 2, config.Services[0].Alerts[5].SuccessThreshold)
+	}
+
+	if config.Services[0].Alerts[6].Type != core.TwilioAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.TwilioAlert, config.Services[0].Alerts[6].Type)
+	}
+	if !config.Services[0].Alerts[6].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[6].FailureThreshold != 12 {
+		t.Errorf("The default failure threshold of the alert should've been %d, but it was %d", 12, config.Services[0].Alerts[6].FailureThreshold)
+	}
+	if config.Services[0].Alerts[6].SuccessThreshold != 15 {
+		t.Errorf("The default success threshold of the alert should've been %d, but it was %d", 15, config.Services[0].Alerts[6].SuccessThreshold)
+	}
+}
+
+func TestParseAndValidateConfigBytesWithAlertingAndDefaultAlertAndMultipleAlertsOfSameTypeWithOverriddenParameters(t *testing.T) {
+	config, err := parseAndValidateConfigBytes([]byte(`
+alerting:
+  slack:
+    webhook-url: "http://example.com"
+    default-alert:
+      enabled: true
+      description: "description"
+
+services:
+ - name: twinnation
+   url: https://twinnation.org/health
+   alerts:
+     - type: slack
+       failure-threshold: 10
+     - type: slack
+       failure-threshold: 20
+       description: "wow"
+     - type: slack
+       enabled: false
+       failure-threshold: 30
+   conditions:
+     - "[STATUS] == 200"
+`))
+	if err != nil {
+		t.Error("expected no error, got", err.Error())
+	}
+	if config == nil {
+		t.Fatal("Config shouldn't have been nil")
+	}
+	// Alerting providers
+	if config.Alerting == nil {
+		t.Fatal("config.Alerting shouldn't have been nil")
+	}
+	if config.Alerting.Slack == nil || !config.Alerting.Slack.IsValid() {
+		t.Fatal("Slack alerting config should've been valid")
+	}
+	// Services
+	if len(config.Services) != 1 {
+		t.Error("There should've been 2 services")
+	}
+	if config.Services[0].Alerts[0].Type != core.SlackAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.SlackAlert, config.Services[0].Alerts[0].Type)
+	}
+	if config.Services[0].Alerts[1].Type != core.SlackAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.SlackAlert, config.Services[0].Alerts[1].Type)
+	}
+	if config.Services[0].Alerts[2].Type != core.SlackAlert {
+		t.Errorf("The type of the alert should've been %s, but it was %s", core.SlackAlert, config.Services[0].Alerts[2].Type)
+	}
+	if !config.Services[0].Alerts[0].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if !config.Services[0].Alerts[1].IsEnabled() {
+		t.Error("The alert should've been enabled")
+	}
+	if config.Services[0].Alerts[2].IsEnabled() {
+		t.Error("The alert should've been disabled")
+	}
+	if config.Services[0].Alerts[0].GetDescription() != "description" {
+		t.Errorf("The description of the alert should've been %s, but it was %s", "description", config.Services[0].Alerts[0].GetDescription())
+	}
+	if config.Services[0].Alerts[1].GetDescription() != "wow" {
+		t.Errorf("The description of the alert should've been %s, but it was %s", "description", config.Services[0].Alerts[1].GetDescription())
+	}
+	if config.Services[0].Alerts[2].GetDescription() != "description" {
+		t.Errorf("The description of the alert should've been %s, but it was %s", "description", config.Services[0].Alerts[2].GetDescription())
+	}
+	if config.Services[0].Alerts[0].FailureThreshold != 10 {
+		t.Errorf("The failure threshold of the alert should've been %d, but it was %d", 10, config.Services[0].Alerts[0].FailureThreshold)
+	}
+	if config.Services[0].Alerts[1].FailureThreshold != 20 {
+		t.Errorf("The failure threshold of the alert should've been %d, but it was %d", 20, config.Services[0].Alerts[1].FailureThreshold)
+	}
+	if config.Services[0].Alerts[2].FailureThreshold != 30 {
+		t.Errorf("The failure threshold of the alert should've been %d, but it was %d", 30, config.Services[0].Alerts[2].FailureThreshold)
 	}
 }
 
@@ -711,7 +1061,7 @@ services:
 func TestParseAndValidateConfigBytesWithValidSecurityConfig(t *testing.T) {
 	const expectedUsername = "admin"
 	const expectedPasswordHash = "6b97ed68d14eb3f1aa959ce5d49c7dc612e1eb1dafd73b1e705847483fd6a6c809f2ceb4e8df6ff9984c6298ff0285cace6614bf8daa9f0070101b6c89899e22"
-	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`
+	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`debug: true
 security:
   basic:
     username: "%s"

core/alert.go

@@ -2,20 +2,29 @@ package core
 
 // Alert is the service's alert configuration
 type Alert struct {
-	// Type of alert
+	// Type of alert (required)
 	Type AlertType `yaml:"type"`
 
 	// Enabled defines whether or not the alert is enabled
-	Enabled bool `yaml:"enabled"`
+	//
+	// This is a pointer, because it is populated by YAML and we need to know whether it was explicitly set to a value
+	// or not for provider.ParseWithDefaultAlert to work.
+	Enabled *bool `yaml:"enabled"`
 
 	// FailureThreshold is the number of failures in a row needed before triggering the alert
 	FailureThreshold int `yaml:"failure-threshold"`
 
 	// Description of the alert. Will be included in the alert sent.
-	Description string `yaml:"description"`
+	//
+	// This is a pointer, because it is populated by YAML and we need to know whether it was explicitly set to a value
+	// or not for provider.ParseWithDefaultAlert to work.
+	Description *string `yaml:"description"`
 
 	// SendOnResolved defines whether to send a second notification when the issue has been resolved
-	SendOnResolved bool `yaml:"send-on-resolved"`
+	//
+	// This is a pointer, because it is populated by YAML and we need to know whether it was explicitly set to a value
+	// or not for provider.ParseWithDefaultAlert to work. Use Alert.IsSendingOnResolved() for a non-pointer
+	SendOnResolved *bool `yaml:"send-on-resolved"`
 
 	// SuccessThreshold defines how many successful executions must happen in a row before an ongoing incident is marked as resolved
 	SuccessThreshold int `yaml:"success-threshold"`
@@ -35,6 +44,30 @@ type Alert struct {
 	Triggered bool
 }
 
+// GetDescription retrieves the description of the alert
+func (alert Alert) GetDescription() string {
+	if alert.Description == nil {
+		return ""
+	}
+	return *alert.Description
+}
+
+// IsEnabled returns whether an alert is enabled or not
+func (alert Alert) IsEnabled() bool {
+	if alert.Enabled == nil {
+		return false
+	}
+	return *alert.Enabled
+}
+
+// IsSendingOnResolved returns whether an alert is sending on resolve or not
+func (alert Alert) IsSendingOnResolved() bool {
+	if alert.SendOnResolved == nil {
+		return false
+	}
+	return *alert.SendOnResolved
+}
+
 // AlertType is the type of the alert.
 // The value will generally be the name of the alert provider
 type AlertType string

core/alert_test.go

@@ -0,0 +1,36 @@
+package core
+
+import "testing"
+
+func TestAlert_IsEnabled(t *testing.T) {
+	if (Alert{Enabled: nil}).IsEnabled() {
+		t.Error("alert.IsEnabled() should've returned false, because Enabled was set to nil")
+	}
+	if value := false; (Alert{Enabled: &value}).IsEnabled() {
+		t.Error("alert.IsEnabled() should've returned false, because Enabled was set to false")
+	}
+	if value := true; !(Alert{Enabled: &value}).IsEnabled() {
+		t.Error("alert.IsEnabled() should've returned true, because Enabled was set to true")
+	}
+}
+
+func TestAlert_GetDescription(t *testing.T) {
+	if (Alert{Description: nil}).GetDescription() != "" {
+		t.Error("alert.GetDescription() should've returned an empty string, because Description was set to nil")
+	}
+	if value := "description"; (Alert{Description: &value}).GetDescription() != value {
+		t.Error("alert.GetDescription() should've returned false, because Description was set to 'description'")
+	}
+}
+
+func TestAlert_IsSendingOnResolved(t *testing.T) {
+	if (Alert{SendOnResolved: nil}).IsSendingOnResolved() {
+		t.Error("alert.IsSendingOnResolved() should've returned false, because SendOnResolved was set to nil")
+	}
+	if value := false; (Alert{SendOnResolved: &value}).IsSendingOnResolved() {
+		t.Error("alert.IsSendingOnResolved() should've returned false, because SendOnResolved was set to false")
+	}
+	if value := true; !(Alert{SendOnResolved: &value}).IsSendingOnResolved() {
+		t.Error("alert.IsSendingOnResolved() should've returned true, because SendOnResolved was set to true")
+	}
+}

core/service.go

@@ -161,7 +161,7 @@ func (service *Service) GetAlertsTriggered() []Alert {
 		return alerts
 	}
 	for _, alert := range service.Alerts {
-		if alert.Enabled && alert.FailureThreshold == service.NumberOfFailuresInARow {
+		if alert.IsEnabled() && alert.FailureThreshold == service.NumberOfFailuresInARow {
 			alerts = append(alerts, *alert)
 			continue
 		}

core/service_test.go

@@ -28,7 +28,7 @@ func TestService_ValidateAndSetDefaults(t *testing.T) {
 	if len(service.Alerts) != 1 {
 		t.Error("Service should've had 1 alert")
 	}
-	if service.Alerts[0].Enabled {
+	if service.Alerts[0].IsEnabled() {
 		t.Error("Service alert should've defaulted to disabled")
 	}
 	if service.Alerts[0].SuccessThreshold != 2 {
@@ -93,11 +93,12 @@ func TestService_ValidateAndSetDefaultsWithDNS(t *testing.T) {
 
 func TestService_GetAlertsTriggered(t *testing.T) {
 	condition := Condition("[STATUS] == 200")
+	enabled := true
 	service := Service{
 		Name:       "twinnation-health",
 		URL:        "https://twinnation.org/health",
 		Conditions: []*Condition{&condition},
-		Alerts:     []*Alert{{Type: PagerDutyAlert, Enabled: true}},
+		Alerts:     []*Alert{{Type: PagerDutyAlert, Enabled: &enabled}},
 	}
 	service.ValidateAndSetDefaults()
 	if service.NumberOfFailuresInARow != 0 {

jsonpath/jsonpath.go

@@ -41,7 +41,7 @@ func extractValue(currentKey string, value interface{}) interface{} {
 		tmp := strings.SplitN(currentKey, "[", 3)
 		arrayIndex, err := strconv.Atoi(strings.Replace(tmp[1], "]", "", 1))
 		if err != nil {
-			return value
+			return nil
 		}
 		currentKey := tmp[0]
 		// if currentKey contains only an index (i.e. [0] or 0)

jsonpath/jsonpath_test.go

@@ -20,6 +20,15 @@ func TestEval(t *testing.T) {
 	}
 }
 
+func TestEvalWithInvalidData(t *testing.T) {
+	path := "simple"
+	data := `invalid data`
+	_, _, err := Eval(path, []byte(data))
+	if err == nil {
+		t.Error("expected an error")
+	}
+}
+
 func TestEvalWithInvalidPath(t *testing.T) {
 	path := "errors"
 	data := `{}`
@@ -75,6 +84,16 @@ func TestEvalWithArrayOfValues(t *testing.T) {
 	}
 }
 
+func TestEvalWithArrayOfValuesAndInvalidIndex(t *testing.T) {
+	path := "ids[wat]"
+	data := `{"ids": [1, 2]}`
+
+	_, _, err := Eval(path, []byte(data))
+	if err == nil {
+		t.Error("Expected an error")
+	}
+}
+
 func TestEvalWithRootArrayOfValues(t *testing.T) {
 	path := "[1]"
 	data := `[1, 2]`

watchdog/alerting.go

@@ -26,25 +26,25 @@ 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.IsEnabled() || alert.FailureThreshold > service.NumberOfFailuresInARow {
 			continue
 		}
 		if alert.Triggered {
 			if cfg.Debug {
-				log.Printf("[watchdog][handleAlertsToTrigger] Alert for service=%s with description='%s' has already been TRIGGERED, skipping", service.Name, alert.Description)
+				log.Printf("[watchdog][handleAlertsToTrigger] Alert for service=%s with description='%s' has already been TRIGGERED, skipping", service.Name, alert.GetDescription())
 			}
 			continue
 		}
 		alertProvider := config.GetAlertingProviderByAlertType(cfg, alert.Type)
 		if alertProvider != nil && alertProvider.IsValid() {
-			log.Printf("[watchdog][handleAlertsToTrigger] Sending %s alert because alert for service=%s with description='%s' has been TRIGGERED", alert.Type, service.Name, 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.GetDescription())
 			customAlertProvider := alertProvider.ToCustomAlertProvider(service, alert, result, false)
 			// TODO: retry on error
 			var err error
 			// We need to extract the DedupKey from PagerDuty's response
 			if alert.Type == core.PagerDutyAlert {
 				var body []byte
-				if body, err = customAlertProvider.Send(service.Name, alert.Description, false); err == nil {
+				if body, err = customAlertProvider.Send(service.Name, alert.GetDescription(), false); err == nil {
 					var response pagerDutyResponse
 					if err = json.Unmarshal(body, &response); err != nil {
 						log.Printf("[watchdog][handleAlertsToTrigger] Ran into error unmarshaling pagerduty response: %s", err.Error())
@@ -54,7 +54,7 @@ func handleAlertsToTrigger(service *core.Service, result *core.Result, cfg *conf
 				}
 			} else {
 				// All other alert types don't need to extract anything from the body, so we can just send the request right away
-				_, err = customAlertProvider.Send(service.Name, alert.Description, false)
+				_, err = customAlertProvider.Send(service.Name, alert.GetDescription(), false)
 			}
 			if err != nil {
 				log.Printf("[watchdog][handleAlertsToTrigger] Failed to send an alert for service=%s: %s", service.Name, err.Error())
@@ -70,21 +70,21 @@ func handleAlertsToTrigger(service *core.Service, result *core.Result, cfg *conf
 func handleAlertsToResolve(service *core.Service, result *core.Result, cfg *config.Config) {
 	service.NumberOfSuccessesInARow++
 	for _, alert := range service.Alerts {
-		if !alert.Enabled || !alert.Triggered || alert.SuccessThreshold > service.NumberOfSuccessesInARow {
+		if !alert.IsEnabled() || !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 {
+		if !alert.IsSendingOnResolved() {
 			continue
 		}
 		alertProvider := config.GetAlertingProviderByAlertType(cfg, alert.Type)
 		if alertProvider != nil && alertProvider.IsValid() {
-			log.Printf("[watchdog][handleAlertsToResolve] Sending %s alert because alert for service=%s with description='%s' has been RESOLVED", alert.Type, service.Name, 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.GetDescription())
 			customAlertProvider := alertProvider.ToCustomAlertProvider(service, alert, result, true)
 			// TODO: retry on error
-			_, err := customAlertProvider.Send(service.Name, alert.Description, true)
+			_, err := customAlertProvider.Send(service.Name, alert.GetDescription(), true)
 			if err != nil {
 				log.Printf("[watchdog][handleAlertsToResolve] Failed to send an alert for service=%s: %s", service.Name, err.Error())
 			} else {

watchdog/alerting_test.go

@@ -25,15 +25,16 @@ func TestHandleAlerting(t *testing.T) {
 		},
 	}
 	config.Set(cfg)
+	enabled := true
 	service := &core.Service{
 		URL: "http://example.com",
 		Alerts: []*core.Alert{
 			{
 				Type:             core.CustomAlert,
-				Enabled:          true,
+				Enabled:          &enabled,
 				FailureThreshold: 2,
 				SuccessThreshold: 3,
-				SendOnResolved:   true,
+				SendOnResolved:   &enabled,
 				Triggered:        false,
 			},
 		},
@@ -78,15 +79,16 @@ func TestHandleAlertingWithBadAlertProvider(t *testing.T) {
 		Alerting: &alerting.Config{},
 	}
 	config.Set(cfg)
+	enabled := true
 	service := &core.Service{
 		URL: "http://example.com",
 		Alerts: []*core.Alert{
 			{
 				Type:             core.CustomAlert,
-				Enabled:          true,
+				Enabled:          &enabled,
 				FailureThreshold: 1,
 				SuccessThreshold: 1,
-				SendOnResolved:   true,
+				SendOnResolved:   &enabled,
 				Triggered:        false,
 			},
 		},
@@ -113,15 +115,16 @@ func TestHandleAlertingWhenTriggeredAlertIsAlmostResolvedButServiceStartFailingA
 		},
 	}
 	config.Set(cfg)
+	enabled := true
 	service := &core.Service{
 		URL: "http://example.com",
 		Alerts: []*core.Alert{
 			{
 				Type:             core.CustomAlert,
-				Enabled:          true,
+				Enabled:          &enabled,
 				FailureThreshold: 2,
 				SuccessThreshold: 3,
-				SendOnResolved:   true,
+				SendOnResolved:   &enabled,
 				Triggered:        true,
 			},
 		},
@@ -147,15 +150,17 @@ func TestHandleAlertingWhenTriggeredAlertIsResolvedButSendOnResolvedIsFalse(t *t
 		},
 	}
 	config.Set(cfg)
+	enabled := true
+	disabled := false
 	service := &core.Service{
 		URL: "http://example.com",
 		Alerts: []*core.Alert{
 			{
 				Type:             core.CustomAlert,
-				Enabled:          true,
+				Enabled:          &enabled,
 				FailureThreshold: 1,
 				SuccessThreshold: 1,
-				SendOnResolved:   false,
+				SendOnResolved:   &disabled,
 				Triggered:        true,
 			},
 		},
@@ -179,15 +184,16 @@ func TestHandleAlertingWhenTriggeredAlertIsResolvedPagerDuty(t *testing.T) {
 		},
 	}
 	config.Set(cfg)
+	enabled := true
 	service := &core.Service{
 		URL: "http://example.com",
 		Alerts: []*core.Alert{
 			{
 				Type:             core.PagerDutyAlert,
-				Enabled:          true,
+				Enabled:          &enabled,
 				FailureThreshold: 1,
 				SuccessThreshold: 1,
-				SendOnResolved:   true,
+				SendOnResolved:   &enabled,
 				Triggered:        false,
 			},
 		},
@@ -215,15 +221,16 @@ func TestHandleAlertingWithProviderThatReturnsAnError(t *testing.T) {
 		},
 	}
 	config.Set(cfg)
+	enabled := true
 	service := &core.Service{
 		URL: "http://example.com",
 		Alerts: []*core.Alert{
 			{
 				Type:             core.CustomAlert,
-				Enabled:          true,
+				Enabled:          &enabled,
 				FailureThreshold: 2,
 				SuccessThreshold: 2,
-				SendOnResolved:   true,
+				SendOnResolved:   &enabled,
 				Triggered:        false,
 			},
 		},
@@ -273,15 +280,16 @@ func TestHandleAlertingWithProviderThatOnlyReturnsErrorOnResolve(t *testing.T) {
 		},
 	}
 	config.Set(cfg)
+	enabled := true
 	service := &core.Service{
 		URL: "http://example.com",
 		Alerts: []*core.Alert{
 			{
 				Type:             core.CustomAlert,
-				Enabled:          true,
+				Enabled:          &enabled,
 				FailureThreshold: 1,
 				SuccessThreshold: 1,
-				SendOnResolved:   true,
+				SendOnResolved:   &enabled,
 				Triggered:        false,
 			},
 		},