help - how to customize template tinc-up.j2?

[damko]

I need to force a couple of routes in tinc-up.j2 for just one specific host but I don't get how to do it.

I realize that this is probably more "lack of understanding of the whole debops structure" than "a debops.tinc issue". I apologize for this.

However, I see in main.yml

src: 'etc/tinc/network/tinc-up.j2'

I suppose that I can put tinc-up.j2 in some prioritized subdir in my ansible tree but I don't get where and with which structure so that my custom template will apply to just one machine.

[drybjed]

Funnily enough, this is what the template_src lookup plugin whould let you do if it was used here. Unfortunately, it's not a part of Ansible core, and makes usage of roles that use these plugins a bit more difficult, so I try to avoid them and would like to fix the issues that call for their usage in DebOps.

Instead, perhaps you could introduce new parameters, item.tinc_up_options and item.tinc_down_options, that allow for extra commands at the end of the scripts. That way you can do something like this:

In ansible/inventory/host_vars/hostname/tinc.yml add:

extra_routes: [ 'list', 'of', 'route', 'commands' ]

tinc__networks:
  'mesh0':
    tinc_up_options: '{{ extra_routes }}'

Just a mockup, not sure if it works. I see a problem with this right now since debops.tinc works on a list of networks and it would be hard in the current design of the role to add routes just on one node in a specific network...

Perhaps another alternative would be to add something akin to an "include", since the tinc-up and tinc-down scripts are shell scripts, they should easily be able to execute other commands. Maybe something like tinc-pre-up-hook, tinc-post-up-hook, tinc-pre-down-hook, tinc-post-down-hook. These scripts wouldn't be managed by debops.tinc itself, but you could create them either by hand or via debops.resources role, with fine-grained control over what goes where.

I think that would be a much more elegant solution... Do you want to try it? If so, work on debops/debops repository fork, so it can be easily merged later.

[damko]

thank you a lot for the awesome reply and, wow, the debops.resources you've mentioned is a true revelation for me! Is this module even mentioned in the "get started" and "customization" parts of the manual?

I like a lot the second solution with hooks which I'd love to try and experiment. I need to find some time for it though.

For now, as quick fix, I've used a per-host playbook that I run this way:

debops service/tinc -l hostname_here ansible/playbooks/hostname_here.yml

Basically in the playbook I simply manipulate the tinc-up content. Maybe this tip can come in handy to someone else.

[drybjed]

No, debops.resources role is not mentioned in any guides, and maybe it should be. At the moment, documentation in the DebOps monorepo is in an unfinished state - I want to move the role documentation to the main docs/ directory, but at the moment that would break lots of reference links, so I need to deal with the defaults/main.yml files first, ie. generate .rst files from them. I know how, just go sidetracked by the role tests. But it's coming. :-)

[damko]

I see the issue but, to be clear, be aware that I wasn't complaining at all. I was just wondering. Debops is just AWESOME. Period.

[drybjed]

Of couse, I know. And thanks. :-)