11:16 a.m.
hey there,
during the last couple of days I was thinking about how to structure multiple systems with
groups and child-groups [1].
In my view, maybe there are two ways how to solve it. You can group by logical/physical
location (all systems on one base-machine), or you can differ between the services running
on systems (e.g. webserver-systems, vm-basis etc.).
Actually this is fine, if you use ansible without DebOps. But actually I would like to use
DebOps ;) and this leads me to an unexpected behavior.
The possibility to provide groups variables which will be combined with host variables are
really nice, if you need to specify more details host configurations. But the situation,
that a host can be part of multiple groups and every group can have special configuration
does not well.
For example:
HostA is part of GroupA und GroupB. If you specify apt_install
'apt_install__group_packages' for both groups in 'inventory/groups_vars/',
there is no combination and no easy way to find out, which
'apt_install__group_packages' are taken. Furthermore there is no easy way to
determine what are all group_vars, which will be are relevant for a hosts, maybe to detect
variable-collisions.
Now I am wondering, what are your 'best practices' to manage your
groups/group_vars. Are you only using groups_vars for services and never for locations.
But how will you even handle this problem there. What if your systems are base machine,
which are in group [debops_service_libvirtd] and you want to additionally install libvirt
extensions with 'apt_install' and parallel the same systems are in
[debops_service_mount] and you want to 'apt_install' extensions there too.
best and thanks for any conversation : )
javud
[1]
https://docs.ansible.com/ansible/latest/user_guide/intro_inventory.html#i...
12:47 p.m.
Hello
In order to specify a host as belonging to two groups I wrote an
inventory plugin to solve this issue. The plugin automatically merges /
appends group variables that are lists.
It's still experimental, but it works, and I use it myself of course.
You can find an example of group merging in the test case roster-14.yml.
https://gitlab.com/ansible-kheops/plugins/roster
Regards,
Julien
On 08.10.2020 11:16, javud wrote:
> hey there,
>
> during the last couple of days I was thinking about how to structure
> multiple systems with groups and child-groups [1].
> In my view, maybe there are two ways how to solve it. You can group by
> logical/physical location (all systems on one base-machine), or you
> can differ between the services running on systems (e.g.
> webserver-systems, vm-basis etc.).
>
> Actually this is fine, if you use ansible without DebOps. But actually
> I would like to use DebOps ;) and this leads me to an unexpected
> behavior.
> The possibility to provide groups variables which will be combined
> with host variables are really nice, if you need to specify more
> details host configurations. But the situation, that a host can be
> part of multiple groups and every group can have special configuration
> does not well.
>
> For example:
> HostA is part of GroupA und GroupB. If you specify apt_install
> 'apt_install__group_packages' for both groups in
> 'inventory/groups_vars/', there is no combination and no easy way to
> find out, which 'apt_install__group_packages' are taken. Furthermore
> there is no easy way to determine what are all group_vars, which will
> be are relevant for a hosts, maybe to detect variable-collisions.
>
> Now I am wondering, what are your 'best practices' to manage your
> groups/group_vars. Are you only using groups_vars for services and
> never for locations. But how will you even handle this problem there.
> What if your systems are base machine, which are in group
> [debops_service_libvirtd] and you want to additionally install libvirt
> extensions with 'apt_install' and parallel the same systems are in
> [debops_service_mount] and you want to 'apt_install' extensions there
> too.
>
> best and thanks for any conversation : )
> javud
>
> [1]
>
https://docs.ansible.com/ansible/latest/user_guide/intro_inventory.html#i...
1:43 p.m.
On paź 08, javud wrote:
Now I am wondering, what are your 'best practices' to manage
your
groups/group_vars. Are you only using groups_vars for services and never for
locations. But how will you even handle this problem there. What if your
systems are base machine, which are in group [debops_service_libvirtd] and
you want to additionally install libvirt extensions with 'apt_install' and
parallel the same systems are in [debops_service_mount] and you want to
'apt_install' extensions there too.
One possibility is to just use a dynamic inventory script and handle the
variables in that script. You can either write your own or use an existing
implementation. But this might be relatively easier than wrestling with YAML
in the Ansible inventory and merging multiple variables by hand.
If you care only about APT package installation itself, there's a trick in
DebOps you can use to your advantage. All DebOps roles have a special variable
for listing additional packages to install, usually named
'<role>__packages'.
Based on your example, if you want to install some packages on all hosts with
the 'libvirtd' service, you can add them into the role group variables:
---
# ansible/inventory/group_vars/debops_service_libvirtd
libvirtd__packages:
- 'zsh'
- 'tmux'
With this, the additional packages will be installed when you execute the
'libvirtd' role.
-- Maciej
2:03 p.m.
On paź 08, Maciej Delmanowski wrote:
---
# ansible/inventory/group_vars/debops_service_libvirtd
libvirtd__packages:
- 'zsh'
- 'tmux'
A better location for the variables:
---
# ansible/inventory/group_vars/debops_service_libvirtd/libvirtd.yml
libvirtd__packages:
- 'zsh'
- 'tmux'
Cheers,
Maciej
5:32 p.m.
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Hash: SHA512
Hi
This is also an issue for me with no really good solution. One of my workarounds is to put
it into group_vars/all/default.yml, example:
```yaml
resources__files:
- path: '/usr/lib/check_mk_agent/plugins/entropy_avail'
src:
'/home/user/src/HeinleinSupport/check_mk/entropy_avail/agents/plugins/entropy_avail'
mode: '0755'
state: '{{ "present" if (ansible_distribution == "Debian" and
"debops_service_checkmk_agent" in group_names) else "absent" }}'
```
For SaltStack, I did quite a bit of research and found
https://docs.saltstack.com/en/master/ref/pillar/all/salt.pillar.stack.html which solves
this for me at work. Note that in the SaltStack world, it is way more common to have
hierarchical pillar structure (comparable to Ansible inventory) like `resources.files` so
some merging strategy is also way more important than with Ansible.
I have yet to find something like that for Ansible. But I have not really looked around so
I will closely follow this thread :)
- --
Live long and prosper
Robin `ypid` Schneider -- https://me.ypid.de/
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1293
days inactive
1295
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4 comments
4 participants
participants (4)
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javud -
Julien Lecomte -
Maciej Delmanowski -
Robin Schneider