feature: add alertmanager function

config/email.tmpl

@@ -1,6 +1,6 @@
 {{ define "email.to.html" }}
 {{ range .Alerts }}
----------------------------------------------------------
+-------------------------openim alert---------------------<br>
 告警程序: prometheus_alert<br>
 告警级别: {{ .Labels.severity }} 级<br>
 告警类型: {{ .Labels.alertname }}<br>
@@ -8,6 +8,8 @@
 故障服务: {{ .Labels.job }}<br>
 告警主题: {{ .Annotations.summary }}<br>
 触发时间: {{ .StartsAt.Format "2020-01-02 15:04:05"}} <br>
-----------------------------------------------------------
+----------------------------------------------------------<br>
+<br>
+<br>
 {{ end }}
 {{ end }}