munin_async
Ansible role for munin-async agent
This Ansible role installs and configure munin-async, a monitoring agent that complements munin-node.
Compared to a bare munin-node setup, the addition of munin-async allows to:
- fetch data over SSH instead of the insecure TCP-based communication protocol used by munin-node
- fetch data asynchronously: the munin-async agent will poll the local munin-node every 5 minutes and persist the resulting data, allowing a munin master to fetch data from munin-async at any time (e.g. every 30 minutes)
See the Munin documentation on munin-async for a more complete overview.
Features and overview
This role does only two things, but does them well:
- install
munin-async
andmunin-node
on a target system, with support for several operating systems - copy the public SSH key of the munin master so that it can fetch data from this target system
It is recommended to use a separate role to configure munin-node to your liking, such as the munin-node role from geerlingguy.
Configuration of the munin master needs to be done separately.
Installation
This role is available on Ansible Galaxy
Requirements
This role has been tested to run on Debian (from wheezy to bullseye), Ubuntu, CentOS 7 and 8, Fedora, and OpenBSD.
It should also work on all other Debian-derivatives and RedHat-derivatives.
Role variables
This role has a single variable:
munin_async_sshpubkeys: []
A list of SSH public keys that will be installed in the munin-async user home, to allow the munin master node to connect via SSH.
How to use
Start by generating a pair of SSH keys on your munin master:
$ sudo -u munin ssh-keygen
$ cat /var/lib/munin/.ssh/id_rsa.pub
On your ansible controller, add this SSH key to the munin_async_sshpubkeys
variable.
This can be done either through a group_vars
file, or directly in your playbook.
Assuming you have a group named monitorednodes
:
# Playbook: munin-async.yml
- hosts: monitorednodes
vars:
munin_async_sshpubkeys: ["ssh-rsa AAAAB3NzaC1y...m/mRpZR munin@munin-master"]
roles:
- { role: munin-async }
Apply this playbook to your nodes:
$ ansible-playbook munin-async.yml
This will install and configure munin-async
with the SSH key of the munin master.
Finally, on your munin master, you need to declare each node that needs to be monitored:
# /etc/munin/munin-conf.d/machines.conf
[foo.example.com]
address ssh://[email protected]:22
use_node_name yes
Of course, you could write a simple role/playbook to manage that through ansible as well.
Hacking
Adding support for an OS
To add support for a new OS, the first step is to add variables in
vars/OSFAMILY.yml
where OSFAMILY
is what ansible reports as ansible_os_family
.
For example:
munin_async_service: munin-asyncd
munin_async_clientbin: /usr/share/munin/munin-async
munin_async_user: munin-async
munin_async_group: munin-async
munin_async_home: /var/lib/munin-async
These variables should match the munin-async package for the OS where applicable.
If no user is created by the package, the username and home can be chosen arbitrarily.
It is recommended to use munin-async
for consistency (to help configure the munin master
in an uniform way). This user should have read access to the munin-async data, e.g.
/var/lib/munin-async/
on Debian or /var/lib/munin/spool/
on Red-Hat systems.
Then, add a file tasks/install-YOUROS.yml
that should:
- install an appropriate munin-async package (or even install it manually)
- if necessary, create a user named
{{ munin_async_user }}
with home directory{{ munin_async_home }}
- if necessary, create a service named
{{ munin_async_service }}
to start/stop the daemon
Lastly, include this file in the main tasks file with the right conditional.
License
MIT
ansible-galaxy install zorun/ansible-role-munin-async