# hosts vs groups ini-style config **URL:** \ **Category:** Ansible Project\ **Created:** [May 19, 2012, 10:05pm UTC](https://forum.ansible.com/t/hosts-vs-groups-ini-style-config/11563 "2012-05-19T22:05:50Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Matt\_Goodall](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@Matt\_Goodall](https://forum.ansible.com/u/Matt_Goodall)\ **Post date:** [May 19, 2012, 10:05pm UTC](https://forum.ansible.com/t/hosts-vs-groups-ini-style-config/11563/1 "2012-05-19T22:05:50Z")
Hi, I realise I'm very new to this project, so I put on my flame-proof jacket before posting this ;-), but I \*believe\* the .ini style inventory can be simplified and perhaps made a little more consistent. It seems to me that the inventory is really just a graph of nodes, where each node is basically a name and a set of variables. Doesn't that mean that a host is really just a node with no children and a group is a node with children? Given that assumption, does it actually make sense to differentiate a group of hosts:     [g1]     h1     h2 > From a group of groups:     [g1:children]     g2     [g2]     h3 Couldn't this be simplified right down to:     [g1]     h1     h2     g2     [g2]     h3 This actually works quite nicely with vars too. For example if I have lots of vars for a particular host, I would now have the option to use a [:vars] block for a host as is currently possible for a group instead of a long line of text:     [g1]     h1     [g1:vars]     a=1     [h1:vars]     b=2     c=3     ...     z=26 I think the only downside to this is that you could accidentally end up with something that was supposed to be a group but has no children, and a node with no children is considered a host. However, I would suggest that you didn't mean to have a group with no children, so it should be removed (or commented out at the least). If you're interested in this idea, and I won't be offended it you're not, then I have a working .ini parser that builds the graph of nodes, including support for vars, host ports, etc that I would be happy to share or even try to wire in to Ansible myself. - Matt ---
**Author:** ![Matt\_Goodall](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@Matt\_Goodall](https://forum.ansible.com/u/Matt_Goodall)\ **Post date:** [May 19, 2012, 10:23pm UTC](https://forum.ansible.com/t/hosts-vs-groups-ini-style-config/11563/2 "2012-05-19T22:23:04Z")
> Hi, > > I realise I'm very new to this project, so I put on my flame-proof > jacket before posting this ;-), but I \*believe\* the .ini style > inventory can be simplified and perhaps made a little more consistent. > > It seems to me that the inventory is really just a graph of nodes, > where each node is basically a name and a set of variables. Doesn't > that mean that a host is really just a node with no children and a > group is a node with children? [...] > If you're interested in this idea, and I won't be offended it you're > not, then I have a working .ini parser that builds the graph of nodes, > including support for vars, host ports, etc that I would be happy to > share or even try to wire in to Ansible myself. Here you go, [https://gist.github.com/2732574](https://gist.github.com/2732574). - Matt ---
**Author:** ![Michael\_DeHaan](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Michael\_DeHaan](https://forum.ansible.com/u/Michael_DeHaan)\ **Post date:** [May 19, 2012, 11:02pm UTC](https://forum.ansible.com/t/hosts-vs-groups-ini-style-config/11563/3 "2012-05-19T23:02:22Z")
Well, that would imply a host name and a group name couldn't be the same, right? It is very unlikely but it would be ambiguous in that case. Otherwise I would agree. -- Michael ---
**Author:** ![Matt\_Goodall](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@Matt\_Goodall](https://forum.ansible.com/u/Matt_Goodall)\ **Post date:** [May 19, 2012, 11:12pm UTC](https://forum.ansible.com/t/hosts-vs-groups-ini-style-config/11563/4 "2012-05-19T23:12:57Z")
> Well, that would imply a host name and a group name couldn't be the same, right? It is very unlikely but it would be ambiguous in that case. Yeah, that's true. I'm struggling to come up with a scenario where I would ever name a host and group the same, but anything's possible. > Otherwise I would agree. OK, have a sleep on it in case you think of anything else. If you want me to have a play to see how it works out in practice then let me know, or just grab the code and try it yourself. Thanks for listening :). - Matt ---
**Author:** ![Michael\_DeHaan](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Michael\_DeHaan](https://forum.ansible.com/u/Michael_DeHaan)\ **Post date:** [May 20, 2012, 11:43am UTC](https://forum.ansible.com/t/hosts-vs-groups-ini-style-config/11563/5 "2012-05-20T11:43:32Z")
We're going to keep the 'children' syntax. A few other reasons. If you end up typo'ing a group name, you would end up creating a host, which would be confusing. I am pretty sure I like things being explicit, and not mixing hosts and groups, since the file is easier to audit that way to see if it is what you want it to be. ---
**Author:** ![Matt\_Goodall](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@Matt\_Goodall](https://forum.ansible.com/u/Matt_Goodall)\ **Post date:** [May 20, 2012, 1:30pm UTC](https://forum.ansible.com/t/hosts-vs-groups-ini-style-config/11563/6 "2012-05-20T13:30:59Z")
> > \> Well, that would imply a host name and a group name couldn't be the same, right? It is very unlikely but it would be ambiguous in that case. > > > > Yeah, that's true. I'm struggling to come up with a scenario where I > > would ever name a host and group the same, but anything's possible. > > We're going to keep the 'children' syntax. > > A few other reasons. > > If you end up typo'ing a group name, you would end up creating a host, which would be confusing. Hmm, it's probably worth me mentioning that I have already accidentally added a group to a non [:children] section and had the exact problem you mention above - a group mistaken as a host. Not a typo, but an easy enough mistake to make and took me a while to spot. I've also tried to add a host to a [:children] section, but that does at least give a decent enough error message IIRC. I'm sure I'll get used to where to put things soon ;). > I am pretty sure I like things being explicit, and not mixing hosts and groups, since the file is easier to audit that way to see > if it is what you want it to be. I like having anything in a group in one list, but that's clearly a subjective preference. OK, one more suggestion and then I promise to shut up ;), but if you're aiming for explicit, perhaps [:children] is a little vague? Maybe something like [:groups] would be better? - Matt ---
**Author:** ![Michael\_DeHaan](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Michael\_DeHaan](https://forum.ansible.com/u/Michael_DeHaan)\ **Post date:** [May 20, 2012, 1:52pm UTC](https://forum.ansible.com/t/hosts-vs-groups-ini-style-config/11563/7 "2012-05-20T13:52:30Z")
> OK, one more suggestion and then I promise to shut up ;), but if > you're aiming for explicit, perhaps [:children] is a little vague? > Maybe something like [:groups] would be better? Implicit vs Explicit is different than bike shedding the word choice 🙂 Subgroups is probably technically most accurate, though it's already established and I don't want the code littered with synonym logic. --Michael