AlertManager/Opsgenie - I can't template only by the responder type field

What did you do?
I was setting the built-in alert-manager integration with opsgenie.

What did you expect to see?
I want to template responder type field like all other fields that is templatable.

What did you see instead? Under which circumstances?
When I put a template string at the responder type field I got this error:

ts=2022-04-11T18:35:35.669Z caller=coordinator.go:118 level=error component=configuration msg="Loading configuration file failed" file=/etc/alertmanager/config.yaml err="OpsGenieConfig responder { {{ .CommonLabels.responder_name }}  {{ .commonlabels.responder_type }}} type does not match valid options ^(team|teams|user|escalation|schedule)$"

I think it is a bug because I'm able to template all other fields of opsgenie_configs, such as responder name.

Environment

• System information: quay.io/prometheus/alertmanager:v0.24.0 (conteiner image)
• Alertmanager version: 0.24.0 (branch=HEAD, revision=f484b17fa3c583ed1b2c8bbcec20ba1db2aa5f11)
• Prometheus version: 2.34.0 (prom/prometheus:2.34.0 conteiner image)
• Alertmanager configuration file:

templates:
- '/etc/alertmanager/template/*.tmpl'
global:
  opsgenie_api_key: xxx

receivers:
- name: 'opsgenie'
  opsgenie_configs:
  - send_resolved: true
    message: '{{ .CommonAnnotations.summary }}'
    description: '{{ .CommonAnnotations.description }}'
    source: '{{ .CommonLabels.source }}'
    details:
    responders: 
    - name: '{{ .CommonLabels.responder_name }}'
      # it doesn't work because of this code: 
      # https://github.com/prometheus/alertmanager/blob/a6d10bd5bc3f651e0ca04d47b981ed66e85a09a6/config/notifiers.go#L504
      type: '{{ .CommonLabels.responder_type }}'
    tags: '{{ .CommonLabels.tags }}'
    note: '{{ .CommonLabels.note }}'
    priority: '{{ .CommonLabels.priority }}'
    entity: '{{ .CommonLabels.app }}'
    actions: '{{ .CommonLabels.actions }}'
  

route:
  receiver: 'opsgenie'
  group_by: [ 'app', 'tenant', 'category' ]

• Prometheus - Alert Rules:

groups:
- name: my_alerting_rules
  rules:
  - alert: my_alert
    expr: sample_metric >= 3
    for: 5s
    labels:
      responder_name: 'my-team'
      responder_type: 'team'
      priority: 'P1'
    annotations:
      summary: "[SampleOverflow.Error]: Tenant {{ $labels.tenant }}"
      description: "{{ $value }} samples found for category {{ $labels.category }} on tenant {{ $labels.tenant }}"

• Logs:

"OpsGenieConfig responder { {{ .CommonLabels.responder_name }}  {{ .commonlabels.responder_type }}} type does not match valid options ^(team|teams|user|escalation|schedule)$"```

Start in config/notifiers.go at the referenced Opsgenie responder validation, then trace how responder fields are processed when configuration templates are rendered. Confirm the behavior with the supplied responder_type template and configuration; done means the configuration loads successfully while preserving validation for the allowed responder types.