config: Add alert-mode

README.md

@@ -29,6 +29,9 @@ Example:
 http-address :8080
 # Log level (either debug, info, warning, error)
 log-level info
+# When multiple alerts are grouped together by Alertmanager, they can either be sent
+# each on their own (single mode) or be kept together (multi mode) (either single or multi; default is single)
+alert-mode single
 # Optionally protect with HTTP basic authentication
 user webhookUser
 password webhookPass

config.go

@@ -7,9 +7,17 @@ import (
 	"git.sr.ht/~emersion/go-scfg"
 )
 
+type alertMode int
+
+const (
+	single alertMode = iota
+	multi
+)
+
 type config struct {
 	HTTPAddress string
 	LogLevel    string
+	alertMode   alertMode
 	User        string
 	Password    string
 	ntfy        ntfyConfig
@@ -42,6 +50,7 @@ func readConfig(path string) (*config, error) {
 	// Set default values
 	config.HTTPAddress = "127.0.0.1:8080"
 	config.LogLevel = "info"
+	config.alertMode = single
 
 	d := cfg.Get("log-level")
 	if d != nil {
@@ -57,6 +66,25 @@ func readConfig(path string) (*config, error) {
 		}
 	}
 
+	d = cfg.Get("alert-mode")
+	if d != nil {
+		var mode string
+		if err := d.ParseParams(&mode); err != nil {
+			return nil, err
+		}
+
+		switch strings.ToLower(mode) {
+		case "single":
+			config.alertMode = single
+
+		case "multi":
+			config.alertMode = multi
+
+		default:
+			return nil, fmt.Errorf("%q directive: illegal mode %q", d.Name, mode)
+		}
+	}
+
 	d = cfg.Get("user")
 	if d != nil {
 		if err := d.ParseParams(&config.User); err != nil {

config_test.go

@@ -13,6 +13,9 @@ func TestReadConfig(t *testing.T) {
 http-address :8080
 # Log level (either debug, info, warning, error)
 log-level info
+# When multiple alerts are grouped together by Alertmanager, they can either be sent
+# each on their own (single mode) or be kept together (multi mode) (either single or multi; default is single)
+alert-mode multi
 # Optionally protect with HTTP basic authentication
 user webhookUser
 password webhookPass
@@ -44,7 +47,7 @@ ntfy {
 `
 
 	expectedCfg := &config{
-		HTTPAddress: ":8080", LogLevel: "info", User: "webhookUser", Password: "webhookPass",
+		HTTPAddress: ":8080", LogLevel: "info", alertMode: multi, User: "webhookUser", Password: "webhookPass",
 		ntfy: ntfyConfig{Topic: "https://ntfy.sh/alertmanager-alerts", User: "user", Password: "pass"},
 		labels: labels{Order: []string{"severity", "instance"},
 			Label: map[string]labelConfig{