MSTeams integration message cards actions not supported

[rgarcia89]

With the current state of the MSTeams integration we are not able to define actions next to the title, text and summary. Due to this it is not possible to define buttons that would, for example, provide a silence functionality or a URL to Prometheus, Alertmanager, Runbook or whatever.

https://learn.microsoft.com/en-us/outlook/actionable-messages/message-card-reference#openuri-action

Environment

• Alertmanager version: 0.26.0

  insert output of alertmanager --version here (repeat for each alertmanager
  version in your cluster, if relevant to the issue)

• Prometheus version: 0.70.0

  insert output of prometheus --version here (repeat for each prometheus
  version in your cluster, if relevant to the issue)

[PatrickSpies]

As a kind of workaround: We use html inside the text to add a silence-link:

      msteamsConfigs:
        - text: |2-
            {{ range $index, $alert := .Alerts }}
              {{ if $index }}
            <br />
              {{ end }}
            <hr style='border-color: #{{ if eq $.Status "resolved" }}2DC72D{{ else if eq $.Status "firing" }}{{ if eq $.CommonLabels.severity "critical" }}8C1A1A{{ else if eq $.CommonLabels.severity "error" }}FF4D00{{ else if eq $.CommonLabels.severity "warning" }}FFA500{{ else }}808080{{ end }}{{ else }}808080{{ end }}; border-width: 5px;' />
            <strong>{{ $alert.Annotations.description }}</strong><br />
            <br />
              {{ range $key, $value := $alert.Annotations }}
                {{- if and (ne $key "description") (ne $key "runbook_url") }}
            <strong>{{ $key }}</strong> {{ $value }}<br />
                {{ end -}}
              {{ end -}}
              {{- range $key, $value := $alert.Labels }}
                {{- if ne $key "prometheus" }}
            <strong>{{ $key }}</strong> {{ $value }}<br />
                {{ end -}}
              {{ end }}
              {{ if eq $.Status "firing" -}}
            <br />
            <a href="{{ $.ExternalURL }}/#/silences/new?filter=%7B{{$c := 0}}{{ range $key, $value := $alert.Labels }}{{if $c}}%22%2C%20{{ end }}{{ $c = 1 }}{{ $key }}%3D%22{{ $value }}{{- end }}%22%7D" target='_blank'><button>Silence alert</button></a><br />
              {{- end }}
            {{ end }}

[TheMeier]

See #3324 (comment)

Support for AdaptiveCards would be nice, maybe you can provide a merge request to implement that?