Setting up Alertmanager

Since we are already using Prometheus, it makes sense to deploy Prometheus' companion Alertmanager. It will receive alerts, filter and forward them to the end-points we'll define. Slack will be the first.

Alertmanager Docker image expect us to define a configuration file that defines routes, receivers, and a few other things. One possible configuration can be as follows.

route: 
  receiver: "slack" 
  repeat_interval: 1h 
 
receivers: 
    - name: "slack" 
      slack_configs: 
          - send_resolved: true 
            text: "Something horrible happened! Run for your lives!" 
            api_url: "https://hooks.slack.com/services\
/T308SC7HD/B59ER97SS/S0KvvyStVnIt3ZWpIaLnqLCu" 

The configuration defines the route with slack as the receiver of the alerts. In the receivers section, we specified that we want...