introduce top level alerting config node

config/config.go

@@ -176,10 +176,10 @@ func (u URL) MarshalYAML() (interface{}, error) {
 
 // Config is the top-level configuration for Prometheus's config files.
 type Config struct {
-	GlobalConfig        GlobalConfig     `yaml:"global"`
-	AlertRelabelConfigs []*RelabelConfig `yaml:"alert_relabel_configs,omitempty"`
-	RuleFiles           []string         `yaml:"rule_files,omitempty"`
-	ScrapeConfigs       []*ScrapeConfig  `yaml:"scrape_configs,omitempty"`
+	GlobalConfig   GlobalConfig    `yaml:"global"`
+	AlertingConfig AlertingConfig  `yaml:"alerting,omitempty"`
+	RuleFiles      []string        `yaml:"rule_files,omitempty"`
+	ScrapeConfigs  []*ScrapeConfig `yaml:"scrape_configs,omitempty"`
 
 	// Catches all undefined fields and must be empty after parsing.
 	XXX map[string]interface{} `yaml:",inline"`
@@ -293,6 +293,11 @@ func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	return nil
 }
 
+// AlertingConfig configures alerting and alertmanager related configs
+type AlertingConfig struct {
+	AlertRelabelConfigs []*RelabelConfig `yaml:"alert_relabel_configs,omitempty"`
+}
+
 // GlobalConfig configures values that are used across other configuration
 // objects.
 type GlobalConfig struct {

notifier/notifier.go

@@ -138,7 +138,7 @@ func (n *Notifier) ApplyConfig(conf *config.Config) error {
 	defer n.mtx.Unlock()
 
 	n.opts.ExternalLabels = conf.GlobalConfig.ExternalLabels
-	n.opts.RelabelConfigs = conf.AlertRelabelConfigs
+	n.opts.RelabelConfigs = conf.AlertingConfig.AlertRelabelConfigs
 	return nil
 }