# two bugs in the group depth parsing logic yielding wrong and inconsistently wrong depth values for groups **URL:** \ **Category:** Ansible Project\ **Created:** [May 17, 2013, 1:49pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819 "2013-05-17T13:49:16Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Serge\_van\_Ginderacht](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@Serge\_van\_Ginderacht](https://forum.ansible.com/u/Serge_van_Ginderacht)\ **Post date:** [May 17, 2013, 1:49pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/1 "2013-05-17T13:49:16Z")
Hi, As discussed with Michael on irc yesterday, I suspected something to be wrong with the calculated group depth, which is AFAICS used to have the right variable precedence according to the depth of a group in the parent-child tree. As I’m looking into making a custom inventory script, tailored to our very strict standardized environment, I wanted to have a way to more or less visualize the group tree, and be able to check it on possible errors. To test this (and also to troubleshoot other inventory related stuff) I wrote an “ansible-vars” script based on bin/ansible that parses the inventory, and can show a (tree) list of groups, and a list of hosts with all of their variables. It’s not super clean, but gets the job done for now. (If interested, you can check it out here: [https://github.com/ansible-contrib/ansible-plugins/blob/devel/bin/ansible-vars](https://github.com/ansible-contrib/ansible-plugins/blob/devel/bin/ansible-vars) ) It took me some time to figure this out, as the wrong depth values I got were inconsistent - depended on the level of subdirectories in which the ini files resided - depended on the order of groups as noted in the ini files As it turned out, those were two similar, but different bugs in group.y and dir.py Example: ---
**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:** [May 17, 2013, 2:41pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/2 "2013-05-17T14:41:50Z")
I’m not sure the internal variables in Ansible being weird for you are a symptom. What’s actually the problem? As nicely as possible, please keep “TLDR” in mind a bit 🙂 ---
**Author:** ![Serge\_van\_Ginderacht](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@Serge\_van\_Ginderacht](https://forum.ansible.com/u/Serge_van_Ginderacht)\ **Post date:** [May 18, 2013, 9:11pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/3 "2013-05-18T21:11:59Z")
As I said earlier, the effect on variable precedence can be a corner case. I started assembling a test inventory with some variables, and managed to find a setup where the problem shows. Inventory file, used commands, the expected result and the (wrong) command output can be found in this gist: [https://gist.github.com/sergevanginderachter/5605645](https://gist.github.com/sergevanginderachter/5605645) one example: hosts file contains groups with this structure; all the app\* groups have a variable set to the name of the group . site .. apache ... app2 .... app2-dev --\> these level groups contain the nodes .... app2-prod .. tomcat ... app1 .... app1-dev .... app1-prod running a debug task showing that var: app1-dev-node | success \>\> {"msg": "var=app1"} app1-prod-node | success \>\> {"msg": "var=app1-prod"} app2-dev-node | success \>\> {"msg": "var=app2-dev"} app2-prod-node | success \>\> {"msg": "var=app2"} So some nodes get their var from app1/2 instead of the subgroup with the environment. - pointing the inventory to the hosts file directly, or the parent dir also yields different results - restructuring the order in the ini hosts file can also influence this - in the mean time I discovered that the patch I made does not allways solve the problem More details in the gist.     Serge ---
**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:** [May 18, 2013, 11:59pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/4 "2013-05-18T23:59:12Z")
Please forgive my lack of brain processing power. So if I understand this correctly there are variables defined in the tomcat subtree and variables in the apache subtree, and you’d like them to override in some way? Or which two groups are you not seeing variables blended like you like from? This is why I strongly encourage the use of group\_vars/ to put variables in, makes inventory much easier to read. ---
**Author:** ![Serge\_van\_Ginderacht](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@Serge\_van\_Ginderacht](https://forum.ansible.com/u/Serge_van_Ginderacht)\ **Post date:** [May 19, 2013, 12:25am UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/5 "2013-05-19T00:25:21Z")
> So if I understand this correctly there are variables defined in the > tomcat subtree and variables in the apache subtree, and you'd like them to > override in some way? Or which two groups are you not seeing variables > blended like you like from? To keep things simple, just look that part of my example where the variable 'var' is defined on the app1 and app2 group, and on their respective subgroups. The four '-node' hosts are only defined in those subgroups, and only on 1 single place​​, so there is no overlap, except for parent and child groups 'app\*' Basically, I expect to be able to define var on the app1/2 groups, as a default, and to override them in the childgroups app1/2-dev/prod (in which the nodes are directly defined, and have the greatest depth. This is how precedence is documented: "" If a variable is defined in multiple groups and one group is a child of the other, the child group variable will override the variable set in the parent. "" My tests show that this doesn't allways happen. This is why I strongly encourage the use of group\_vars/\ to put > variables in, makes inventory much easier to read. I normally don't use variables defined in ini files, just did that now now for the sake of giving a complete inventory file.​ to test. ​Serge​ ---
**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:** [May 19, 2013, 1:39pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/6 "2013-05-19T13:39:18Z")
"To keep things simple, just look that part of my example " I’m sorry, your example is not simple. This is why it is very important to submit _minimal_ examples and work things down to the smallest possible question. Just define as few hosts and groups and variables as you possibly can to show this, and pastebin a gist of that. If it can be done with one variable and three groups, show me that. ---
**Author:** ![Serge\_van\_Ginderacht](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@Serge\_van\_Ginderacht](https://forum.ansible.com/u/Serge_van_Ginderacht)\ **Post date:** [May 19, 2013, 5:42pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/7 "2013-05-19T17:42:56Z")
> I'm sorry, your example is not simple. The problem isn't simple also. ​​ > This is why it is very important to submit \*minimal\* examples and work > things down to the smallest possible question. > > Just define as few hosts and groups and variables as you possibly can to > show this, and pastebin a gist of that. I already tried that, it's not easy to find good examples of showing a problem that only affects in certain conditions, in more complex environments. ​​ > If it can be done with one variable and three groups, show me that. ​My example does almost that, it only needs some other groups to trigger the problem/ I might find an example with one variable, defined on two or three group levels, and having some extra groups where no variable is defined. I'll look into that tonight or tomorrow.   Serge ​ ---
**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:** [May 19, 2013, 6:04pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/8 "2013-05-19T18:04:38Z")
Maybe you can draw up some ascii art that would help me understand better, something like this: [http://pastebin.com/PYm47hcu](http://pastebin.com/PYm47hcu) ? ---
**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:** [May 19, 2013, 6:06pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/9 "2013-05-19T18:06:01Z")
Sorry, corrected that a bit, this should be more clear for what I am looking for trying to understand: [http://pastebin.com/vzUrW6Ha](http://pastebin.com/vzUrW6Ha) ---
**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:** [May 19, 2013, 6:07pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/10 "2013-05-19T18:07:21Z")
Rarrgh 🙂 Use this one - [http://pastebin.com/vCRajgjX](http://pastebin.com/vCRajgjX) ---
**Author:** ![Serge\_van\_Ginderacht](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@Serge\_van\_Ginderacht](https://forum.ansible.com/u/Serge_van_Ginderacht)\ **Post date:** [May 20, 2013, 5:00pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/11 "2013-05-20T17:00:27Z")
​I managed to dumb it further down. This example doesn’t show all the possible effects when using the ‘hosts’ ini file directly ​as the inventory, but it does show when putting the hosts file in a subdirectory Keep in mind though that the problem can show up in more complex examples, when only using an ini file as inventory. I should be able to make a more complex example to show that. So I made a simple ini file, also with a small graph of the group tree, containing 2 levels of groups, 2 parent groups with each 2 child groups, 1 node per child group, 4 nodes in total. One single variable ‘var’ is defined on each of the groups. Each node is expected to get the variable of the respective child group it is the sole member of. ​O​ utput shows that​some​ nodes get the variable from the parent group​, in this case when pointing the inventory to a dir containing the ini file.​ ---
**Author:** ![Serge\_van\_Ginderacht](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@Serge\_van\_Ginderacht](https://forum.ansible.com/u/Serge_van_Ginderacht)\ **Post date:** [May 23, 2013, 6:21pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/12 "2013-05-23T18:21:12Z")
Michael, Did you have the time to look into this yet? Do you need more information? Serge ---
**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:** [May 23, 2013, 9:00pm UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/13 "2013-05-23T21:00:28Z")
Haven’t had any time yet, no. Please copy this into a github ticket so we don’t lose it. ---
**Author:** ![Serge\_van\_Ginderacht](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@Serge\_van\_Ginderacht](https://forum.ansible.com/u/Serge_van_Ginderacht)\ **Post date:** [May 24, 2013, 7:53am UTC](https://forum.ansible.com/t/two-bugs-in-the-group-depth-parsing-logic-yielding-wrong-and-inconsistently-wrong-depth-values-for-groups/12819/14 "2013-05-24T07:53:39Z")
​[https://github.com/ansible/ansible/issues/3009​](https://github.com/ansible/ansible/issues/3009%E2%80%8B)