alertmanager.yml

global:
  resolve_timeout: 5m

route:
  group_by: ['alertname']
  group_wait: 10s
  group_interval: 10s
  repeat_interval: 10m
  receiver: 'prometheus-alerter'

receivers:
  - name: 'prometheus-alerter'
    slack_configs:
      - api_url: "${{ secrets.SLACK_API_KEY }}"
        channel: '#alerts'
        icon_url: https://avatars3.githubusercontent.com/u/3380462
        send_resolved: true
        title: |-
          [{{ .Status | toUpper }}{{ if eq .Status "firing" }}:{{ .Alerts.Firing | len }}{{ end }}] {{ .CommonLabels.alertname }} for {{ .CommonLabels.job }}
          {{- if gt (len .CommonLabels) (len .GroupLabels) -}}
            {{" "}}(
            {{- with .CommonLabels.Remove .GroupLabels.Names }}
              {{- range $index, $label := .SortedPairs -}}
                {{ if $index }}, {{ end }}
                {{- $label.Name }}="{{ $label.Value -}}"
              {{- end }}
            {{- end -}}
            )
          {{- end }}
        text: >-      
          *Alert details*:
          
          {{ range .Alerts -}}
            *Alert:* {{ .Annotations.title }}{{ if .Labels.severity }} - `{{ .Labels.severity }}`{{ end }}
          *Description:* {{ .Annotations.description }}
          *Details:*
            {{ range .Labels.SortedPairs }} • *{{ .Name }}:* `{{ .Value }}`
            {{ end }}
          {{ end }}