# Run task only if server belong to some group. **URL:** \ **Category:** Ansible Project\ **Created:** [September 26, 2013, 10:58am UTC](https://forum.ansible.com/t/run-task-only-if-server-belong-to-some-group/13561 "2013-09-26T10:58:38Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Marcin\_Praczko](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@Marcin\_Praczko](https://forum.ansible.com/u/Marcin_Praczko)\ **Post date:** [September 26, 2013, 10:58am UTC](https://forum.ansible.com/t/run-task-only-if-server-belong-to-some-group/13561/1 "2013-09-26T10:58:38Z")
Hi, I have question whether is possible to run task only if server belong to specific group? — Quick scenario — Lets say that on Inventory I have: [targets] srv01 srv02 [webservers] srv01 Now I would like to play ‘common’ roles with tasks following (pseudo code): - name: Do something action: Ansible - action when: server is in webservers group. I know that is possible run another play which runs only on webserves but not quite sure whether this suits to my issue: — Long scenario — I have to cofigure a lot servers belongs to specific groups (web servers / db servers) and munin plugins have some common plugins / and depends of group (www / db). - When one is installing munin-node from RPM (RH based systems) a lot of munin-plugins are created: - Now common role from ansible - removes not requried plugins - restarting munin-node - Then some additional plugins should be configured for server belongs to group www/db Do I would like to avoid situation that: Common plugin removes not required plugins from munin-node (including those for www - like apache), and then another play install this back. I woud really achive somethign like that: - name: Remove not required munin plugins action: when: Server not belong to group WWW … - name: Add plugins for WWW action: when: Server belong to group WWW I look forward to hearing from you. Best regards. ---
**Author:** ![benno\_joy](https://avatars.discourse-cdn.com/v4/letter/b/73ab20/32.png) [@benno\_joy](https://forum.ansible.com/u/benno_joy)\ **Post date:** [September 26, 2013, 11:41am UTC](https://forum.ansible.com/t/run-task-only-if-server-belong-to-some-group/13561/2 "2013-09-26T11:41:27Z")
Hi Marcin, You could do when: ‘webserver’ in group\_names This would make the task run if the current host belongs to webserver group. when: ‘webserver’ not in group\_names would run the task if the current host is not on the webserver group. Hope this helps. Regards, Benno ---
**Author:** ![Michael\_DeHaan2](https://avatars.discourse-cdn.com/v4/letter/m/da6949/32.png) [@Michael\_DeHaan2](https://forum.ansible.com/u/Michael_DeHaan2)\ **Post date:** [September 26, 2013, 12:30pm UTC](https://forum.ansible.com/t/run-task-only-if-server-belong-to-some-group/13561/3 "2013-09-26T12:30:34Z")
“I know that is possible run another play which runs only on webserves but not quite sure whether this suits to my issue:” Actually, it does. hosts: maingroup:&othergroup Means “all hosts in maingroup that are also in othergroup” (maingroup:othergroup would be an “OR”) This is cleaner than the when statement and will produce better output, because it won’t show ‘skipped’ for all the other tasks. ---
**Author:** ![Marcin\_Praczko](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@Marcin\_Praczko](https://forum.ansible.com/u/Marcin_Praczko)\ **Post date:** [September 26, 2013, 5:12pm UTC](https://forum.ansible.com/t/run-task-only-if-server-belong-to-some-group/13561/4 "2013-09-26T17:12:11Z")
Hi, Thank you for help. Both answers are great: 1. Is really nice that ansible supports condition for task based on this whether server belong to group or not. 2. And I agree that is nicer to split tasks on seperate roles to avoid a lot of ‘skipped’ tasks. One more time - thank you for help. ---
**Author:** ![Marcin\_Praczko](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@Marcin\_Praczko](https://forum.ansible.com/u/Marcin_Praczko)\ **Post date:** [October 9, 2013, 3:02pm UTC](https://forum.ansible.com/t/run-task-only-if-server-belong-to-some-group/13561/5 "2013-10-09T15:02:34Z")
Hi, Are you sure that this is working - just tested on ansible 1.3 and I have error: ERROR: Syntax Error while loading YAML script, /src/ansible/roles/mysql-munin/tasks/main.yml Note: The error may actually appear before this position: line 34, column 27 - mysql\_seconds\_behind\_master when: ‘dbslave’ in group\_names ^ I created special role: mysql-munin There are 3 tasks which should be run - 2 of them on DB master - 1 on DB slave. But so far I am struggeling to run task only on server which belongs to specific group. Tasks list: play #3 (Database | Configurtion for database servers): MySQL-munin | Create Munin configuration - Template # Should run on DB servers MySQL-munin | Link Official munin plugins # Should run on DB servers MySQL-munin | Link Custom munin plugins # Should run ONLY on Slave DB server Task: #3 - name: MySQL-munin | Link Custom munin plugins file: src=/opt/munin/lib/plugins/{{ item }} dest=/etc/munin/plugins/{{ item }} state=link with\_items: - mysql\_seconds\_behind\_master notify: - restart munin-node tags: - munin\_conf\_plugin\_mysql # Adding this line when: ‘dbslave’ in group\_names - breaks formating for yaml - Displaying error which I’ve described above. Best regards, Marcin Praczko ---
**Author:** ![Michael\_DeHaan2](https://avatars.discourse-cdn.com/v4/letter/m/da6949/32.png) [@Michael\_DeHaan2](https://forum.ansible.com/u/Michael_DeHaan2)\ **Post date:** [October 9, 2013, 3:07pm UTC](https://forum.ansible.com/t/run-task-only-if-server-belong-to-some-group/13561/6 "2013-10-09T15:07:58Z")
Yep, as this says, this is a YAML syntax error. Since you started the line with a quote, YAML was expecting the whole line to be quoted. This can be fixed by changing when: ‘dbslave’ in group\_names To: when: “‘dbslave’ in group\_names” ---
**Author:** ![Marcin\_Praczko](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@Marcin\_Praczko](https://forum.ansible.com/u/Marcin_Praczko)\ **Post date:** [October 9, 2013, 3:47pm UTC](https://forum.ansible.com/t/run-task-only-if-server-belong-to-some-group/13561/7 "2013-10-09T15:47:21Z")
Hi Michael, This is working now as expected - thank you very much for help. Marcin ---
**Author:** ![Dhruvin\_Shah](https://avatars.discourse-cdn.com/v4/letter/d/dbc845/32.png) [@Dhruvin\_Shah](https://forum.ansible.com/u/Dhruvin_Shah)\ **Post date:** [January 9, 2015, 10:31pm UTC](https://forum.ansible.com/t/run-task-only-if-server-belong-to-some-group/13561/8 "2015-01-09T22:31:36Z")
Surprisingly simple and powerful. It works like a charm. Thanks Michael and everyone.