Add default values for AlertEvery

There is also a test error corrected in TestMonitorFailureAlertEvery
where the same test conditions were repeated twice.

README.md

@@ -55,6 +55,9 @@ The global configurations are:
 |key|value|
 |---|---|
 |`check_interval`|Maximum frequency to run checks for each monitor as duration, eg. 1m2s.|
+|`default_alert_after`|A default value used as an `alert_after` value for a monitor if not specified or 0.|
+|`default_alert_down`|Default down alerts to used by a monitor in case none are provided.|
+|`default_alert_up`|Default up alerts to used by a monitor in case none are provided.|
 |`monitors`|List of all monitors. Detailed description below|
 |`alerts`|List of all alerts. Detailed description below|
 

config.go

@@ -14,6 +14,10 @@ var errInvalidConfig = errors.New("Invalid configuration")
 // Config type is contains all provided user configuration
 type Config struct {
 	CheckInterval     SecondsOrDuration `yaml:"check_interval"`
+	DefaultAlertAfter int16             `yaml:"default_alert_after"`
+	DefaultAlertEvery *int16            `yaml:"default_alert_every"`
+	DefaultAlertDown  []string          `yaml:"default_alert_down"`
+	DefaultAlertUp    []string          `yaml:"default_alert_up"`
 	Monitors          []*Monitor
 	Alerts            map[string]*Alert
 }
@@ -135,8 +139,27 @@ func (config Config) IsValid() (isValid bool) {
 
 // Init performs extra initialization on top of loading the config from file
 func (config *Config) Init() (err error) {
+	for _, monitor := range config.Monitors {
+		if monitor.AlertAfter == 0 && config.DefaultAlertAfter > 0 {
+			monitor.AlertAfter = config.DefaultAlertAfter
+		}
+
+		if monitor.AlertEvery == nil && config.DefaultAlertEvery != nil {
+			monitor.AlertEvery = config.DefaultAlertEvery
+		}
+
+		if len(monitor.AlertDown) == 0 && len(config.DefaultAlertDown) > 0 {
+			monitor.AlertDown = config.DefaultAlertDown
+		}
+
+		if len(monitor.AlertUp) == 0 && len(config.DefaultAlertUp) > 0 {
+			monitor.AlertUp = config.DefaultAlertUp
+		}
+	}
+
 	for name, alert := range config.Alerts {
 		alert.Name = name
+
 		if err = alert.BuildTemplates(); err != nil {
 			return
 		}

config_test.go

@@ -14,6 +14,7 @@ func TestLoadConfig(t *testing.T) {
 		pyCompat   bool
 	}{
 		{"./test/valid-config.yml", false, "Valid config file", false},
+		{"./test/valid-config-default-values.yml", false, "Valid config file with default values", false},
 		{"./test/valid-default-log-alert.yml", false, "Valid config file with default log alert PyCompat", true},
 		{"./test/valid-default-log-alert.yml", true, "Invalid config file no log alert", false},
 		{"./test/does-not-exist", true, "Invalid config path", false},

monitor.go

@@ -12,7 +12,7 @@ import (
 type Monitor struct { //nolint:maligned
 	// Config values
 	AlertAfter    int16             `yaml:"alert_after"`
-	AlertEvery    int16             `yaml:"alert_every"`
+	AlertEvery    *int16            `yaml:"alert_every"`
 	CheckInterval SecondsOrDuration `yaml:"check_interval"`
 	Name          string
 	AlertDown     []string `yaml:"alert_down"`
@@ -129,16 +129,16 @@ func (monitor *Monitor) failure() (notice *AlertNotice) {
 
 	// Use alert cadence to determine if we should alert
 	switch {
-	case monitor.AlertEvery > 0:
+	case monitor.AlertEvery == nil, *monitor.AlertEvery == 0:
-		// Handle integer number of failures before alerting
-		if failureCount%monitor.AlertEvery == 0 {
-			notice = monitor.createAlertNotice(false)
-		}
-	case monitor.AlertEvery == 0:
 		// Handle alerting on first failure only
 		if failureCount == 0 {
 			notice = monitor.createAlertNotice(false)
 		}
+	case *monitor.AlertEvery > 0:
+		// Handle integer number of failures before alerting
+		if failureCount%*monitor.AlertEvery == 0 {
+			notice = monitor.createAlertNotice(false)
+		}
 	default:
 		// Handle negative numbers indicating an exponential backoff
 		if failureCount >= int16(math.Pow(2, float64(monitor.alertCount))-1) { //nolint:gomnd

monitor_test.go

@@ -141,17 +141,19 @@ func TestMonitorSuccess(t *testing.T) {
 // TestMonitorFailureAlertAfter tests that alerts will not trigger until
 // hitting the threshold provided by AlertAfter
 func TestMonitorFailureAlertAfter(t *testing.T) {
+	var alertEvery int16 = 1
+
 	cases := []struct {
 		monitor      Monitor
 		expectNotice bool
 		name         string
 	}{
 		{Monitor{AlertAfter: 1}, true, "Empty"}, // Defaults to true because and AlertEvery default to 0
-		{Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: 1}, true, "Alert after 1: first failure"},
+		{Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: &alertEvery}, true, "Alert after 1: first failure"},
-		{Monitor{failureCount: 1, AlertAfter: 1, AlertEvery: 1}, true, "Alert after 1: second failure"},
+		{Monitor{failureCount: 1, AlertAfter: 1, AlertEvery: &alertEvery}, true, "Alert after 1: second failure"},
-		{Monitor{failureCount: 0, AlertAfter: 20, AlertEvery: 1}, false, "Alert after 20: first failure"},
+		{Monitor{failureCount: 0, AlertAfter: 20, AlertEvery: &alertEvery}, false, "Alert after 20: first failure"},
-		{Monitor{failureCount: 19, AlertAfter: 20, AlertEvery: 1}, true, "Alert after 20: 20th failure"},
+		{Monitor{failureCount: 19, AlertAfter: 20, AlertEvery: &alertEvery}, true, "Alert after 20: 20th failure"},
-		{Monitor{failureCount: 20, AlertAfter: 20, AlertEvery: 1}, true, "Alert after 20: 21st failure"},
+		{Monitor{failureCount: 20, AlertAfter: 20, AlertEvery: &alertEvery}, true, "Alert after 20: 21st failure"},
 	}
 
 	for _, c := range cases {
@@ -172,6 +174,11 @@ func TestMonitorFailureAlertAfter(t *testing.T) {
 // TestMonitorFailureAlertEvery tests that alerts will trigger
 // on the expected intervals
 func TestMonitorFailureAlertEvery(t *testing.T) {
+	var alertEvery0, alertEvery1, alertEvery2 int16
+	alertEvery0 = 0
+	alertEvery1 = 1
+	alertEvery2 = 2
+
 	cases := []struct {
 		monitor      Monitor
 		expectNotice bool
@@ -186,20 +193,20 @@ func TestMonitorFailureAlertEvery(t *testing.T) {
 
 			For usabilty, this should be consistent. Consistent with what though? minitor-py? Or itself? Dun dun duuuunnnnn!
 		*/
-		{Monitor{AlertAfter: 1}, true, "Empty"}, // Defaults to true because AlertAfter and AlertEvery default to 0
+		{Monitor{AlertAfter: 1}, true, "Empty"}, // Defaults to true because AlertAfter and AlertEvery default to nil
 		// Alert first time only, after 1
-		{Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: 0}, true, "Alert first time only after 1: first failure"},
+		{Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: &alertEvery0}, true, "Alert first time only after 1: first failure"},
-		{Monitor{failureCount: 1, AlertAfter: 1, AlertEvery: 0}, false, "Alert first time only after 1: second failure"},
+		{Monitor{failureCount: 1, AlertAfter: 1, AlertEvery: &alertEvery0}, false, "Alert first time only after 1: second failure"},
-		{Monitor{failureCount: 2, AlertAfter: 1, AlertEvery: 0}, false, "Alert first time only after 1: third failure"},
+		{Monitor{failureCount: 2, AlertAfter: 1, AlertEvery: &alertEvery0}, false, "Alert first time only after 1: third failure"},
 		// Alert every time, after 1
-		{Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: 1}, true, "Alert every time after 1: first failure"},
+		{Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: &alertEvery1}, true, "Alert every time after 1: first failure"},
-		{Monitor{failureCount: 1, AlertAfter: 1, AlertEvery: 1}, true, "Alert every time after 1: second failure"},
+		{Monitor{failureCount: 1, AlertAfter: 1, AlertEvery: &alertEvery1}, true, "Alert every time after 1: second failure"},
-		{Monitor{failureCount: 1, AlertAfter: 1, AlertEvery: 1}, true, "Alert every time after 1: third failure"},
+		{Monitor{failureCount: 2, AlertAfter: 1, AlertEvery: &alertEvery1}, true, "Alert every time after 1: third failure"},
 		// Alert every other time, after 1
-		{Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: 2}, true, "Alert every other time after 1: first failure"},
+		{Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: &alertEvery2}, true, "Alert every other time after 1: first failure"},
-		{Monitor{failureCount: 1, AlertAfter: 1, AlertEvery: 2}, false, "Alert every other time after 1: second failure"},
+		{Monitor{failureCount: 1, AlertAfter: 1, AlertEvery: &alertEvery2}, false, "Alert every other time after 1: second failure"},
-		{Monitor{failureCount: 2, AlertAfter: 1, AlertEvery: 2}, true, "Alert every other time after 1: third failure"},
+		{Monitor{failureCount: 2, AlertAfter: 1, AlertEvery: &alertEvery2}, true, "Alert every other time after 1: third failure"},
-		{Monitor{failureCount: 3, AlertAfter: 1, AlertEvery: 2}, false, "Alert every other time after 1: fourth failure"},
+		{Monitor{failureCount: 3, AlertAfter: 1, AlertEvery: &alertEvery2}, false, "Alert every other time after 1: fourth failure"},
 	}
 
 	for _, c := range cases {
@@ -220,6 +227,8 @@ func TestMonitorFailureAlertEvery(t *testing.T) {
 // TestMonitorFailureExponential tests that alerts will trigger
 // with an exponential backoff after repeated failures
 func TestMonitorFailureExponential(t *testing.T) {
+	var alertEveryExp int16 = -1
+
 	cases := []struct {
 		expectNotice bool
 		name         string
@@ -236,7 +245,7 @@ func TestMonitorFailureExponential(t *testing.T) {
 
 	// Unlike previous tests, this one requires a static Monitor with repeated
 	// calls to the failure method
-	monitor := Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: -1}
+	monitor := Monitor{failureCount: 0, AlertAfter: 1, AlertEvery: &alertEveryExp}
 
 	for _, c := range cases {
 		log.Printf("Testing case %s", c.name)

test/valid-config-default-values.yml

@@ -0,0 +1,12 @@
+---
+check_interval: 1
+default_alert_down: ["log_command"]
+default_alert_after: 1
+
+monitors:
+  - name: Command
+    command: ["echo", "$PATH"]
+
+alerts:
+  log_command:
+    command: ["echo", "regular", '"command!!!"', "{{.MonitorName}}"]