Adds ability to run specified alerts on startup

This is helpful to determine if your alerts are valid before an actual failure

main.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"strings"
 	"time"
 
 	"git.iamthefij.com/iamthefij/slog"
@@ -91,9 +92,38 @@ func checkMonitors(config *Config) error {
 	return nil
 }
 
+func sendFirstRunAlerts(config *Config, alertNames []string) error {
+	for _, alertName := range alertNames {
+		var err error
+
+		alert, ok := config.Alerts[alertName]
+		if !ok {
+			err = fmt.Errorf("unknown alert %s: %w", alertName, errUnknownAlert)
+		}
+
+		if err == nil {
+			_, err = alert.Send(AlertNotice{
+				AlertCount:      0,
+				FailureCount:    0,
+				IsUp:            true,
+				LastSuccess:     time.Now(),
+				MonitorName:     fmt.Sprintf("First Run Alert Test: %s", alert.Name),
+				LastCheckOutput: "",
+			})
+		}
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func main() {
 	showVersion := flag.Bool("version", false, "Display the version of minitor and exit")
 	configPath := flag.String("config", "config.yml", "Alternate configuration path (default: config.yml)")
+	firstRunAlerts := flag.String("first-run-alerts", "", "List of alerts to run on startup. This can help determine unhealthy alerts early on. (default \"\")")
 
 	flag.BoolVar(&slog.DebugLevel, "debug", false, "Enables debug logs (default: false)")
 	flag.BoolVar(&ExportMetrics, "metrics", false, "Enables prometheus metrics exporting (default: false)")
@@ -119,6 +149,14 @@ func main() {
 		go ServeMetrics()
 	}
 
+	if *firstRunAlerts != "" {
+		alertNames := strings.Split(*firstRunAlerts, ",")
+
+		err = sendFirstRunAlerts(&config, alertNames)
+
+		slog.OnErrPanicf(err, "Error running first run alerts")
+	}
+
 	// Start main loop
 	for {
 		err = checkMonitors(&config)

main_test.go

@@ -134,3 +134,64 @@ func TestCheckMonitors(t *testing.T) {
 		}
 	}
 }
+
+func TestFirstRunAlerts(t *testing.T) {
+	cases := []struct {
+		config         Config
+		expectErr      bool
+		firstRunAlerts []string
+		name           string
+	}{
+		{
+			config:         Config{},
+			expectErr:      false,
+			firstRunAlerts: []string{},
+			name:           "Empty",
+		},
+		{
+			config:         Config{},
+			expectErr:      true,
+			firstRunAlerts: []string{"missing"},
+			name:           "Unknown",
+		},
+		{
+			config: Config{
+				Alerts: map[string]*Alert{
+					"good": {
+						Command: CommandOrShell{Command: []string{"true"}},
+					},
+				},
+			},
+			expectErr:      false,
+			firstRunAlerts: []string{"good"},
+			name:           "Successful alert",
+		},
+		{
+			config: Config{
+				Alerts: map[string]*Alert{
+					"bad": {
+						Name:    "bad",
+						Command: CommandOrShell{Command: []string{"false"}},
+					},
+				},
+			},
+			expectErr:      true,
+			firstRunAlerts: []string{"bad"},
+			name:           "Failed alert",
+		},
+	}
+
+	for _, c := range cases {
+		err := c.config.Init()
+		if err != nil {
+			t.Errorf("sendFirstRunAlerts(%s): unexpected error reading config: %v", c.name, err)
+		}
+
+		err = sendFirstRunAlerts(&c.config, c.firstRunAlerts)
+		if err == nil && c.expectErr {
+			t.Errorf("sendFirstRunAlerts(%s): Expected error, the code did not error", c.name)
+		} else if err != nil && !c.expectErr {
+			t.Errorf("sendFirstRunAlerts(%s): Did not expect an error, but we got one anyway: %v", c.name, err)
+		}
+	}
+}