Monzo's Alertmanager Slack templates

monzo-alertmanager-config.yaml

###################################################
##
## Alertmanager YAML configuration for routing.
##
## Will route alerts with a code_owner label to the slack-code-owners receiver 
## configured above, but will continue processing them to send to both a
## central Slack channel (slack-monitoring) and PagerDuty receivers
## (pd-warning and pd-critical)
##

routes:
  ###################################################
  ## Duplicate code_owner routes to teams
  ## These will send alerts to team channels but continue
  ## processing through the rest of the tree to handled by on-call
  - match_re:
      code_owner: '.+'
    routes:
      - match: {severity: info|warning|critical}
        continue: true
        receiver: slack-code-owners

  ###################################################
  ## Standard on-call routes
  - match_re:
      severity: info|warning|critical
    receiver: slack-monitoring
    continue: true


  ###################################################
  ## Pagerduty routes
  - match: {severity: warning}
    routes:
    - receiver: pd-warning
  - match: {severity: critical}
    routes:
    - receiver: pd-critical

monzo-alertmanager-receiver.yaml

receivers:
###################################################
## Slack Receivers
- name: slack-code-owners
  slack_configs:
  - channel: '#{{- template "slack.monzo.code_owner_channel" . -}}'
    send_resolved: true
    title: '{{ template "slack.monzo.title" . }}'
    icon_emoji: '{{ template "slack.monzo.icon_emoji" . }}'
    color: '{{ template "slack.monzo.color" . }}'
    text: '{{ template "slack.monzo.text" . }}'
    actions:
    - type: button
      text: 'Runbook :green_book:'
      url: '{{ (index .Alerts 0).Annotations.runbook }}'
    - type: button
      text: 'Query :mag:'
      url: '{{ (index .Alerts 0).GeneratorURL }}'
    - type: button
      text: 'Dashboard :grafana:'
      url: '{{ (index .Alerts 0).Annotations.dashboard }}'
    - type: button
      text: 'Silence :no_bell:'
      url: '{{ template "__alert_silence_link" . }}'
    - type: button
      text: '{{ template "slack.monzo.link_button_text" . }}'
      url: '{{ .CommonAnnotations.link_url }}'

monzo-slack-templates.tmpl

# This builds the silence URL.  We exclude the alertname in the range
# to avoid the issue of having trailing comma separator (%2C) at the end
# of the generated URL
{{ define "__alert_silence_link" -}}
    {{ .ExternalURL }}/#/silences/new?filter=%7B
    {{- range .CommonLabels.SortedPairs -}}
        {{- if ne .Name "alertname" -}}
            {{- .Name }}%3D"{{- .Value -}}"%2C%20
        {{- end -}}
    {{- end -}}
    alertname%3D"{{ .CommonLabels.alertname }}"%7D
{{- end }}



{{ define "__alert_severity_prefix" -}}
    {{ if ne .Status "firing" -}}
    :lgtm:
    {{- else if eq .Labels.severity "critical" -}}
    :fire:
    {{- else if eq .Labels.severity "warning" -}}
    :warning:
    {{- else -}}
    :question:
    {{- end }}
{{- end }}

{{ define "__alert_severity_prefix_title" -}}
    {{ if ne .Status "firing" -}}
    :lgtm:
    {{- else if eq .CommonLabels.severity "critical" -}}
    :fire:
    {{- else if eq .CommonLabels.severity "warning" -}}
    :warning:
    {{- else if eq .CommonLabels.severity "info" -}}
    :information_source:
    {{- else -}}
    :question:
    {{- end }}
{{- end }}


{{/* First line of Slack alerts */}}
{{ define "slack.monzo.title" -}}
    [{{ .Status | toUpper -}}
    {{ if eq .Status "firing" }}:{{ .Alerts.Firing | len }}{{- end -}}
    ] {{ template "__alert_severity_prefix_title" . }} {{ .CommonLabels.alertname }}
{{- end }}


{{/* Color of Slack attachment (appears as line next to alert )*/}}
{{ define "slack.monzo.color" -}}
    {{ if eq .Status "firing" -}}
        {{ if eq .CommonLabels.severity "warning" -}}
            warning
        {{- else if eq .CommonLabels.severity "critical" -}}
            danger
        {{- else -}}
            #439FE0
        {{- end -}}
    {{ else -}}
    good
    {{- end }}
{{- end }}


{{/* Emoji to display as user icon (custom emoji supported!) */}}
{{ define "slack.monzo.icon_emoji" }}:prometheus:{{ end }}

{{/* The test to display in the alert */}}
{{ define "slack.monzo.text" -}}
    {{ range .Alerts }}
        {{- if .Annotations.message }}
            {{ .Annotations.message }}
        {{- end }}
        {{- if .Annotations.description }}
            {{ .Annotations.description }}
        {{- end }}
    {{- end }}
{{- end }}



{{- /* If none of the below matches, send to #monitoring-no-owner, and we 
can then assign the expected code_owner to the alert or map the code_owner
to the correct channel */ -}}
{{ define "__get_channel_for_code_owner" -}}
    {{- if eq . "platform-team" -}}
        platform-alerts
    {{- else if eq . "security-team" -}}
        security-alerts
    {{- else -}}
        monitoring-no-owner
    {{- end -}}
{{- end }}

{{- /* Select the channel based on the code_owner. We only expect to get
into this template function if the code_owners label is present on an alert.
This is to defend against us accidentally breaking the routing logic. */ -}}
{{ define "slack.monzo.code_owner_channel" -}}
    {{- if .CommonLabels.code_owner }}
        {{ template "__get_channel_for_code_owner" .CommonLabels.code_owner }}
    {{- else -}}
        monitoring
    {{- end }}
{{- end }}

{{ define "slack.monzo.link_button_text" -}}
    {{- if .CommonAnnotations.link_text -}}
        {{- .CommonAnnotations.link_text -}}
    {{- else -}}
        Link
    {{- end }} :link:
{{- end }}

Thank for the template.
If anybody has issue with "Silence" button on mobile devices (when press Silence on phone nothing happens, button doesn't open Alertmanager silence link), just change quotes (") to (%22) in __alert_silence_link template.
Hope this help.

Awesome thx, why second, third alert has indentation?

It's not an indentation, it's censoring the name of their Prometheus instance

Hi @dewey ! ,

I think there is not about censoring , but actually some indentation appears at second , third , x, item of a range .
My example :

SSL certificate expires in less than 30 days for instance A .
           SSL certificate expires in less than 30 days for instance B.
           SSL certificate expires in less than 30 days for instance C .
           SSL certificate expires in less than 30 days for instance D.

No idea , how to get rid of it .
I changed the definition of text to take only description annotations in template but unfortunately it doesn't work .

                {{/* The text to display in the alert */}}
                {{ define "slack.monzo.text" -}}
                    {{ range .Alerts }}
                        {{- if .Annotations.description }}
                            {{ .Annotations.description }}
                        {{- end }}
                    {{- end }}
                {{- end }}

Have anyone ideas ?

@ioncoa Remove the indentation from the go template function. E.g.

{{/* The text to display in the alert */}}
{{ define "slack.monzo.text" -}}
{{ range .Alerts }}
{{- if .Annotations.description }}
{{ .Annotations.description }}
{{- end }}
{{- end }}
{{- end }}

Addition for Grafana Alerting integration with AlertManager:

ℹ️ You have to set alertmanger.externalUrl to your Grafana instance external URL

    {{ define "__grafana_alert_silence_link" -}}
        {{ .ExternalURL }}/alerting/silence/new?
        {{- range .CommonLabels.SortedPairs -}}
            matcher={{- .Name }}%3D{{- .Value | urlquery -}}&
        {{- end -}}
    {{- end }}

Addition for Grafana Alerting integration with AlertManager:

ℹ️ You have to set alertmanger.externalUrl to your Grafana instance external URL

    {{ define "__grafana_alert_silence_link" -}}
        {{ .ExternalURL }}/alerting/silence/new?
        {{- range .CommonLabels.SortedPairs -}}
            matcher={{- .Name }}%3D{{- .Value | urlquery -}}&
        {{- end -}}
    {{- end }}

Thanks @aorfanos

Have you also found a way to get the query button working towards Grafana? Alternatively, an external Prometheus?