fedora-image-uploader: configure message publishing

The service will soon emit messages when new images are uploaded. This
grants it access to publish under the fedora_image_uploader topic.

Specific topics under the org.fedoraproject.prod prefix look like:

  fedora_image_uploader.azure.Fedora-Cloud-40.aarch64
  fedora_image_uploader.container.fedora.f40

playbooks/openshift-apps/cloud-image-uploader.yml

@@ -9,6 +9,10 @@
     - /srv/web/infra/ansible/vars/{{ ansible_distribution }}.yml
 
   roles:
+  - role: rabbit/user
+    username: "cloud-image-uploader{{ env_suffix }}"
+    sent_topics: ^org\.fedoraproject\.{{ env_short }}\.fedora_image_uploader\..*
+
   - role: rabbit/queue
     username: "cloud-image-uploader{{ env_suffix }}"
     queue_name: "cloud-image-uploader{{ env_suffix }}"

roles/openshift-apps/cloud-image-uploader/templates/config.toml

@@ -5,6 +5,12 @@
 amqp_url = "amqps://cloud-image-uploader{{ env_suffix }}:@rabbitmq{{ env_suffix }}.fedoraproject.org/%2Fpubsub"
 callback = "fedora_image_uploader:Uploader"
 passive_declares = true
+publish_exchange = "amq.topic"
+{% if env == "staging" %}
+topic_prefix = "org.fedoraproject.stg"
+{% else %}
+topic_prefix = "org.fedoraproject.prod"
+{% endif %}
 
 [tls]
 ca_cert = "/etc/pki/rabbitmq/ca/cloud-image-uploader.ca"