# How does merging hashes work?

**URL:** <https://forum.ansible.com/t/how-does-merging-hashes-work/13535>\
**Category:** Ansible Project\
**Created:** [September 23, 2013, 6:26pm UTC](https://forum.ansible.com/t/how-does-merging-hashes-work/13535 "2013-09-23T18:26:24Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![David\_Reagan](https://avatars.discourse-cdn.com/v4/letter/d/71e660/32.png) [@David\_Reagan](https://forum.ansible.com/u/David_Reagan)\
**Post date:** [September 23, 2013, 6:26pm UTC](https://forum.ansible.com/t/how-does-merging-hashes-work/13535/1 "2013-09-23T18:26:24Z")

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How does merging hashes work?

I’ve set “hash\_behaviour=merge” in my ansible.cfg file. So my hashes should merge. But they don’t. Or at least, not in a way that makes sense to me. Here’s pretty much what I have:

file: group\_vars/testgroup  
stuff:  
substuff:

- path: /b/a/c  
owner: root  
group: root  
recurse: no
- path: /for/the/breakfast  
owner: someone  
group: root  
recurse: no

file: host\_vars/testserver  
stuff:  
substuff:

- path: /another/dir  
owner: root  
group: root  
recurse: no
- path: /yet/another/dir  
owner: someone  
group: root  
recurse: no

testserver is in the testgroup.

What I expect is to get all 4 directories created or modified. What I get is only the directories in the host\_vars file.

Now, if I do something like:

file: group\_vars/testgroup  
stuff:  
substuff:  
blah: this is blah  
blah2: this is blah2

file: host\_vars/testserver  
stuff:  
substuff:  
blah3: this is blah3  
blah4: this is blah4

I do get all four “blah”'s. But that syntax is rather bad for adding things like owner and group…

So, why doesn’t the first one work?

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<div class="post-metadata">

**Author:** ![James\_Cammarata1](https://avatars.discourse-cdn.com/v4/letter/j/d26b3c/32.png) [@James\_Cammarata1](https://forum.ansible.com/u/James_Cammarata1)\
**Post date:** [September 23, 2013, 7:00pm UTC](https://forum.ansible.com/t/how-does-merging-hashes-work/13535/2 "2013-09-23T19:00:32Z")

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If the sub-entries are dictionaries, they will be merged as well. The issue appears that the substuff entry is a list, so it’s just re-assigning/copying those entries. If you make substuff a dictionary, I believe this will work as you expect.

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**Author:** ![David\_Reagan](https://avatars.discourse-cdn.com/v4/letter/d/71e660/32.png) [@David\_Reagan](https://forum.ansible.com/u/David_Reagan)\
**Post date:** [September 23, 2013, 7:09pm UTC](https://forum.ansible.com/t/how-does-merging-hashes-work/13535/3 "2013-09-23T19:09:39Z")

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Yeah, I just figured out that the ‘-’ indicates a list…

The problem is that when I switch to something like:

nfs\_automount:  
mountpoints:  
adminshare:  
path: /path/to/dir/  
owner: root  
group: root  
mode: 755  
recurse: no  
test:  
path: /mounts/test/  
owner: root  
group: root  
mode: 755  
recurse: no

And try to run a task like:

name: ensure nfs mountpoints exist  
file: path={{ nfs\_automount.mountpoints[item].path }} state=directory group={{ nfs\_automount.mountpoints[item].group }} owner={{ nfs\_automount.mountpoints[item].owner }} mode={{ nfs\_automount.mountpoints[item].mode }}  
with\_items: nfs\_automount.mountpoints|default()  
notify: restart nfs\_automount  
tags: nfs\_automount

It errors saying: with\_items expects a list.

So, I need a list in order to loop through the items. But I need a dictionary in order to merge things…

What I’d like to do is have some group values in the group\_vars file, but be able to override/add to them in the host\_vars file.

Is there a decent way I can do that? Or do I just need to copy the vars from group\_vars into host\_vars when I need to add/override them?

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<div class="post-metadata">

**Author:** ![David\_Reagan](https://avatars.discourse-cdn.com/v4/letter/d/71e660/32.png) [@David\_Reagan](https://forum.ansible.com/u/David_Reagan)\
**Post date:** [September 23, 2013, 11:00pm UTC](https://forum.ansible.com/t/how-does-merging-hashes-work/13535/4 "2013-09-23T23:00:09Z")

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Well, it took some experimenting, but I figured it out thanks to [https://groups.google.com/d/msg/ansible-project/M-FNUK9Wz98/1wF23CZ-6pIJ](https://groups.google.com/d/msg/ansible-project/M-FNUK9Wz98/1wF23CZ-6pIJ)

To summarize, I had to pass the dictionary to dictsort so that it would create a list. Then I had to figure out the correct syntax to reference the values. Below is what I ended up with.

- name: ensure nfs mountpoints exist  
file: path={{ item[1].path }} state=directory group={{ item[1].group }} owner={{ item[1].owner }} mode={{ item[1].mode }}  
with\_items: nfs\_automount.mountpoints|dictsort  
notify: restart nfs\_automount  
tags: nfs\_automount