How to create new system service by ansible-playbook

Question

I have created a script to start/stop my application. Now I want to add it as a centos system service. First I created a task to create a link from my script to /etc/init.d/service_name as below.

---  - name: create startup link   file: src={{ cooltoo_service_script }} dest={{ cooltoo_service_init }} state=link 

After create the service, I want to add it to system service. The command used to do that is "chkconfig --add service_name". I wonder whether there is a ansible module to do that instead of hardcoded the command in ansible-playbook file. I have looked at this page http://docs.ansible.com/ansible/service_module.html but it only shows how to manage a service not create a new one.

Answer 1

The below code snippet will create Service in CentOS 7.

Code

Tasks

/tasks/main.yml

- name: TeamCity | Create environment file   template: src=teamcity.env.j2 dest=/etc/sysconfig/teamcity - name: TeamCity | Create Unit file   template: src=teamcity.service.j2 dest=/lib/systemd/system/teamcity.service mode=644   notify:     - reload systemctl - name: TeamCity | Start teamcity   service: name=teamcity.service state=started enabled=yes 

Templates

/templates/teamcity.service.j2

[Unit] Description=JetBrains TeamCity Requires=network.target After=syslog.target network.target [Service] Type=forking EnvironmentFile=/etc/sysconfig/teamcity ExecStart={{teamcity.installation_path}}/bin/teamcity-server.sh start ExecStop={{teamcity.installation_path}}/bin/teamcity-server.sh stop User=teamcity PIDFile={{teamcity.installation_path}}/teamcity.pid Environment="TEAMCITY_PID_FILE_PATH={{teamcity.installation_path}}/teamcity.pid" [Install] WantedBy=multi-user.target 

\templates\teamcity.env.j2

TEAMCITY_DATA_PATH="{{ teamcity.data_path }}" 

Handlers

\handlers\main.yml

- name: reload systemctl   command: systemctl daemon-reload 

Reference :

• Ansible playbook structure: http://docs.ansible.com/ansible/playbooks_intro.html
• SystemCtl: https://www.digitalocean.com/community/tutorials/how-to-use-systemctl-to-manage-systemd-services-and-units

Answer 2

The 'service' module supports an 'enabled' argument.

Here's an example part of a playbook, which I will freely admit does look like a newbie attempt. This assumes RHEL/CentOS 6.x, which uses SysV, not systemd.

  - name: install rhel sysv supervisord init script     copy: src=etc/rc.d/init.d/supervisord dest=/etc/rc.d/init.d/supervisord owner=root group=root mode=0755    - name: install rhel sysv supervisord sysconfig     copy: src=etc/sysconfig/supervisord dest=/etc/sysconfig/supervisord owner=root group=root mode=0640    - name: enable sysv supervisord service     service: name=supervisord enabled=yes    - name: start supervisord     service: name=supervisord state=started 

IMPORTANT A lot of custom init scripts WILL FAIL with Ansible and SysV init; the reason being that the 'status' option (service supervisord status) needs to a return an LSB-compliant return code. Otherwise, Ansible will not know if a service is up or down, and idempotency will fail (restart will still work because that is unconditional)

Here's part of a script, which I've just rewritten to make use of the 'status' function within /etc/init.d/functions (you'll notice this same pattern in other Red Hat provided init-scripts in /etc/init.d/

status)     /usr/bin/supervisorctl $OPTIONS status     status -p $PIDFILE supervisord     # The 'status' option should return one of the LSB-defined return-codes,     # in particular, return-code 3 should mean that the service is not     # currently running. This is particularly important for Ansible's 'service'     # module, as without this behaviour it won't know if a service is up or down.     RETVAL=$?     ;; 

Reference: http://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/iniscrptact.html

If the status action is requested, the init script will return the following exit status codes.

0 program is running or service is OK 1 program is dead and /var/run pid file exists 2 program is dead and /var/lock lock file exists 3 program is not running 4 program or service status is unknown 5-99 reserved for future LSB use 100-149 reserved for distribution use 150-199 reserved for application use 200-254 reserved