prometheus/alertmanager/notification/alerta.yml

parameters:
  _param:
    alertmanager_notification_alerta_host: alerta
    alertmanager_notification_alerta_port: 8080
  prometheus:
    alertmanager:
      enabled: true
      config:
        route:
          routes:
            alerta:
              receiver: HTTP-alerta
              continue: true
        receiver:
          HTTP-alerta:
            enabled: true
            webhook_configs:
              alerta:
                url: "http://${_param:alertmanager_notification_alerta_host}:${_param:alertmanager_notification_alerta_port}/api/webhooks/prometheus"
                send_resolved: true
                http_config:
                  basic_auth:
                    username: "${_param:alerta_admin_username}"
                    password: "${_param:alerta_admin_password}"