Add exporter container if metrics shall be exposed.

tasks/main.yml

@@ -62,6 +62,16 @@
     mode: '0640'
   tags: config
 
+- name: Provide metric exporter environment
+  template:
+    src: templates/exporter.env.j2
+    dest: "{{ jitsi_install_path }}/jitsi/exporter.env"
+    owner: "{{ jitsi_install_user }}"
+    group: "{{ jitsi_install_user }}"
+    mode: '0640'
+  tags: config
+  when: jitsi_expose_metrics
+
 - name: "docker-compose: Teardown existing Jitsi service"
   docker_compose:
     project_src: "{{ jitsi_install_path }}/jitsi/"