Reload systemd after installing rabbitmq

To ensure that the rabbitmq-server service is registered, reload the
systemd daemon after installing the rabbitmq package.

Change-Id: I33f7e6d5647509371a29c368f5cf0a21ab2a5ef7

tasks/install_apt.yml

@@ -45,6 +45,7 @@
 - name: Install the RabbitMQ package
   apt:
     deb: "{{ rabbitmq_package_path }}"
+  register: install_rabbitmq
   tags:
     - rabbitmq-package-deb
     - rabbitmq-apt-packages

tasks/install_yum.yml

@@ -37,6 +37,7 @@
 - name: Install the RabbitMQ package
   yum:
     name: "{{ rabbitmq_package_path }}"
+  register: install_rabbitmq
   tags:
     - rabbitmq-package-rpm
     - rabbitmq-yum-packages

tasks/main.yml

@@ -24,6 +24,18 @@
   tags:
     - always
 
+- name: Check init system
+  command: cat /proc/1/comm
+  register: _pid1_name
+  tags:
+    - always
+
+- name: Set the name of pid1
+  set_fact:
+    pid1_name: "{{ _pid1_name.stdout }}"
+  tags:
+    - always
+
 - include: rabbitmq_pre_install.yml
 
 # The install process will be skipped if `rabbitmq_ignore_version_state=true`

tasks/rabbitmq_install.yml

@@ -27,6 +27,15 @@
   tags:
     - rabbitmq-yum-packages
 
+- name: Reload the systemd daemon
+  command: "systemctl daemon-reload"
+  when:
+    - install_rabbitmq | changed
+    - pid1_name == "systemd"
+  tags:
+    - rabbitmq-apt-packages
+    - rabbitmq-yum-packages
+
 - name: Install pip packages
   pip:
     name: "{{ item }}"