Alertmanager data source
Grafana includes built-in support for Prometheus Alertmanager. It is presently in alpha and not accessible unless 
 Note: Currently, the Cortex implementation of Prometheus Alertmanager is required to edit rules. Configure the Alertmanager data sources by updating Grafana’s configuration files. For more information on how it works and the settings available, refer to the provisioning docs page. Here is an example for provisioning the Alertmanager data source:
Provision the Alertmanager data source
apiVersion: 1
datasources:
  - name: Alertmanager
    type: alertmanager
    url: http://localhost:9090
    access: proxy
    # optionally
    basicAuth: true
    basicAuthUser: my_user
    basicAuthPassword: test_password