group_vars on many groups ?

[Charly Koza]

Hello !

I somehow need to

- assign applications to groups of hosts

- have a host in several groups in the platform

- get the list of deployed applications in the platform

- be able to get the list of hosts with the application.

I tried like that : 

I'm trying to have a variable (dokku_apps) defined for multiple groups.

depending on the target server (testing, prod, and so on), a single host can use many groups or only one.

the idea is that a group should configure some dokku apps. so if a host is in many groups it should configure dokku apps specific to each of its group

my problem is that when a host is in many groups, the dokku_apps (configured in group_vars) is only from a single group (the latest i think) and is not merged (as expected from documentation) 

I'm also using this list (dokku_apps) to configure varnish.

How can i achieve that ?

[Serge van Ginderachter]

​Given that variables are merged according to group priorities, and there is no some default way to add-up some lists, this is hard to achive cleanly.​

A workaround might be to put this data in dictionaries, and enable dict merging in ansible.cfg

TBH, I never found a clean wat to do this kind of construct. It should be something we want to enable when revamping inventory things.