# loops and variables **URL:** \ **Category:** Ansible Project\ **Created:** [May 22, 2014, 12:21pm UTC](https://forum.ansible.com/t/loops-and-variables/15302 "2014-05-22T12:21:35Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Makimoto\_Marakatti](https://avatars.discourse-cdn.com/v4/letter/m/e19adc/32.png) [@Makimoto\_Marakatti](https://forum.ansible.com/u/Makimoto_Marakatti)\ **Post date:** [May 22, 2014, 12:21pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/1 "2014-05-22T12:21:35Z")
Hi all Could someone lend me a hand to figure looping over variables? I’ve got a number of hosts which are grouped in the inventory quite strictly in a rather traditional way: ` dev-group1 hostA hostB tst-group1 hostC hostD pre-group1 hostE hostF pro-group1 hostG hostH dev-group2 hostI hostJ tst-group2 hostK hostL and so on… ` I’m about to replace/template a great number of files in them and I’d like to have local backups first 😉 The only requirement is that the files have to be fetched to an already established structure that mimics the inventory: ` /backup/dev-group1/ /backup/tst-group1/ etc… ` So I made an attempt to loop over each group: ` $ ansible-playbook fetch\_from\_server.yml -sK --extra-vars “@fetch\_loop\_vars.yml” -v ` fetch\_loop\_vars.yml looks like this: ` ---
**Author:** ![Abhijit\_Menon-Sen2](https://avatars.discourse-cdn.com/v4/letter/a/ea5d25/32.png) [@Abhijit\_Menon-Sen2](https://forum.ansible.com/u/Abhijit_Menon-Sen2)\ **Post date:** [May 22, 2014, 12:40pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/2 "2014-05-22T12:40:03Z")
This task isn't actually using a loop in the Ansible sense. You need to provide a list to iterate over using with\_items: or similar. For a more detailed explanation, see [http://docs.ansible.com/playbooks\_loops.html](http://docs.ansible.com/playbooks_loops.html) (it has lots of examples). That said, I don't know the best way to iterate over the hosts in a subset of all your groups in quite the way you describe. Perhaps the examples on the following page will prove helpful: [http://docs.ansible.com/playbooks\_variables.html#magic-variables-and-how-to-access-information-about-other-hosts](http://docs.ansible.com/playbooks_variables.html#magic-variables-and-how-to-access-information-about-other-hosts) -- ams ---
**Author:** ![Abhijit\_Menon-Sen2](https://avatars.discourse-cdn.com/v4/letter/a/ea5d25/32.png) [@Abhijit\_Menon-Sen2](https://forum.ansible.com/u/Abhijit_Menon-Sen2)\ **Post date:** [May 22, 2014, 1:04pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/3 "2014-05-22T13:04:59Z")
I'm sorry, my earlier answer was short-sighted. I started thinking about loops because your Subject said "loop", but you were right to not use an Ansible loop in the first place—at least not over groups/hosts. As I understand it, trying to write a single task that loops over groups and hosts isn't the way to do things in Ansible. One should write a task that fetches the desired files, and run it against the desired hosts by using the existing host-selection mechanism, as described in [http://docs.ansible.com/intro\_patterns.html](http://docs.ansible.com/intro_patterns.html) So you could do something like:     - name: fetch files from the server       fetch: src={{ item }}         dest=/backup/{{ group\_names[0] }}/{{ inventory\_hostname }}/{{ item | basename }}       with\_items:         - /root/.bash\_profile         - /some/other/file Note that group\_names is a list variable that contains the name of all groups that the current host is in. If your hosts aren't in multiple groups, this should not matter to you. If they are, then the backups will be stored only in the directory of the first group by this task. Hope this helps. -- ams ---
**Author:** ![Makimoto\_Marakatti](https://avatars.discourse-cdn.com/v4/letter/m/e19adc/32.png) [@Makimoto\_Marakatti](https://forum.ansible.com/u/Makimoto_Marakatti)\ **Post date:** [May 22, 2014, 1:21pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/4 "2014-05-22T13:21:28Z")
Thanks for the insightful answer. I’m definitely going to try this and will write here how it goes ---
**Author:** ![Makimoto\_Marakatti](https://avatars.discourse-cdn.com/v4/letter/m/e19adc/32.png) [@Makimoto\_Marakatti](https://forum.ansible.com/u/Makimoto_Marakatti)\ **Post date:** [May 22, 2014, 2:57pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/5 "2014-05-22T14:57:10Z")
Well it does work… but for the ‘wrong’ groups. Let me explain: There’s another layer of groups in the inventory to define in which datacentre a particular host is. So in a group like dev-group1 we might have 2 machines in datacentre-A and other 2 hosts in datacentre-B. In this case I’m not interested in where a box is. I need to refer to it by it’s role. (Not the ansible role, but what it does 🙂 ) So that is why I had this arbitrary list of groups read from a variable. And that is still what I would need. I’m thinking to make a play to define those vars and including another one so I can use the “with\_items” construct. If someone has come across something like this before, I would love to hear about it! We have a number of defined groups which we need ---
**Author:** ![Brian\_Coca1](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Brian\_Coca1](https://forum.ansible.com/u/Brian_Coca1)\ **Post date:** [May 22, 2014, 3:51pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/6 "2014-05-22T15:51:54Z")
you can try just rewriting my\_groups this way: my\_groups: “0dm-sap:dev-sap:tst-sap:pre-sap:pro-sap” ---
**Author:** ![Makimoto\_Marakatti](https://avatars.discourse-cdn.com/v4/letter/m/e19adc/32.png) [@Makimoto\_Marakatti](https://forum.ansible.com/u/Makimoto_Marakatti)\ **Post date:** [May 23, 2014, 10:05am UTC](https://forum.ansible.com/t/loops-and-variables/15302/7 "2014-05-23T10:05:25Z")
Brian: Unfortunately that yields this: ` changed: [hostA] =\> {“changed”: true, “dest”: “/backup/ **0dm-sap:dev-sap:tst-sap:pre-sap:pro-sap/hostA/hostA** /root/.bash\_profile”, “md5sum”: “bab9333347e752b87add49020919a078”, “remote\_md5sum”: “bab9333347e752b87add49020919a078”} ` I also failed to make this work declaring vars and including another play. So I guess it’s back to the usual: roles. But for this particular task, that seems so inelegant… thanks to all ---
**Author:** ![Brian\_Coca1](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Brian\_Coca1](https://forum.ansible.com/u/Brian_Coca1)\ **Post date:** [May 23, 2014, 12:16pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/8 "2014-05-23T12:16:23Z")
yeah, didn’t realize you were reusing it for the task also, my ‘fix’ would work only for hosts: entry.​ ---
**Author:** ![Michael\_DeHaan1](https://avatars.discourse-cdn.com/v4/letter/m/5e9695/32.png) [@Michael\_DeHaan1](https://forum.ansible.com/u/Michael_DeHaan1)\ **Post date:** [May 23, 2014, 12:44pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/9 "2014-05-23T12:44:41Z")
Or make a group that contains those groups as children, so it’s cleaner 🙂 ---
**Author:** ![Michael\_DeHaan1](https://avatars.discourse-cdn.com/v4/letter/m/5e9695/32.png) [@Michael\_DeHaan1](https://forum.ansible.com/u/Michael_DeHaan1)\ **Post date:** [May 23, 2014, 12:47pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/10 "2014-05-23T12:47:28Z")
You could make a backup role and do something like this: - hosts: group1 roles: - { role: backup, path: ‘group1’ } - hosts: group2 roles: - { role: backup, path: ‘group2’ } A host can be in lots of groups, so you shouldn’t rely on the group\_names variable to tell you what you are looping over. For instance, a host could be in a group based on purpose and another based on geography. ---
**Author:** ![Makimoto\_Marakatti](https://avatars.discourse-cdn.com/v4/letter/m/e19adc/32.png) [@Makimoto\_Marakatti](https://forum.ansible.com/u/Makimoto_Marakatti)\ **Post date:** [May 23, 2014, 12:54pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/11 "2014-05-23T12:54:06Z")
> A host can be in lots of groups, so you shouldn’t rely on the group\_names variable to tell you what you are looping over. Well that was why I was using “my\_groups”. I do have a lot of groups in the inventory… Your suggestion seems to be like something that could work. I’ll try to adapt that and report back. Thanks! ---
**Author:** ![Dimon](https://avatars.discourse-cdn.com/v4/letter/d/eb8c5e/32.png) [@Dimon](https://forum.ansible.com/u/Dimon)\ **Post date:** [May 23, 2014, 8:04pm UTC](https://forum.ansible.com/t/loops-and-variables/15302/12 "2014-05-23T20:04:55Z")
Why not “with\_nested”? as per ams: - name: fetch files from the server fetch: src={{ item }} dest=/backup/{{ item[1] }}/{{ inventory\_hostname }}/{{ item[0] | basename }} with\_nested: - [/root/.bash\_profile, /some/other/file] - group\_names better yet - provide list of files as a variable. ---
**Author:** ![Makimoto\_Marakatti](https://avatars.discourse-cdn.com/v4/letter/m/e19adc/32.png) [@Makimoto\_Marakatti](https://forum.ansible.com/u/Makimoto_Marakatti)\ **Post date:** [May 26, 2014, 10:19am UTC](https://forum.ansible.com/t/loops-and-variables/15302/13 "2014-05-26T10:19:40Z")
Just seen this today. Will give it a try soon… Thanks!