Ridiculous, but collectd exec plugins cannot accept arguments.

So we have to template our script and "hardcode" the process we want to
monitor there.

playbooks/groups/notifs-backend.yml

@@ -63,6 +63,8 @@
   roles:
   - fedmsg/hub
   - notifs/backend
+  - role: collectd/fedmsg-service
+    process: fedmsg-hub
 
   vars_files: 
    - /srv/web/infra/ansible/vars/global.yml

roles/collectd/fedmsg-service/tasks/main.yml

@@ -2,13 +2,13 @@
 
 - name: Copy in /usr/local/bin/fedmsg-service-collectd
   copy: >
-    src=fedmsg-service-collectd.py
+    template=fedmsg-service-collectd.py
-    dest=/usr/local/bin/fedmsg-service-collectd
+    dest="/usr/local/bin/fedmsg-service-collectd-{{ process }}"
     mode=0755
   notify: restart collectd
 
 - name: Copy in /etc/collectd.d/fedmsg-service.conf
   template: >
     src=fedmsg-service.conf
-    dest=/etc/collectd.d/{{ process }}-conf
+    dest=/etc/collectd.d/{{ process }}.conf
   notify: restart collectd

roles/collectd/fedmsg-service/templates/fedmsg-service-collectd.py

@@ -43,7 +43,7 @@ def print_producer(service, producer):
 
 
 if __name__ == '__main__':
-    service, = sys.argv[-1:]
+    service = "{{ process }}"
     fname = '/var/run/fedmsg/monitoring-%s.socket' % service
 
     if not os.path.exists(fname):

roles/collectd/fedmsg-service/templates/fedmsg-service.conf

@@ -1,4 +1,4 @@
 LoadPlugin exec
 <Plugin exec>
-    Exec "{{ process }}" "/usr/local/bin/fedmsg-service-collectd {{ process }}"
+    Exec "fedmsg" "/usr/local/bin/fedmsg-service-collectd-{{ process }}"
 </Plugin>