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completes munin

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waldek 2021-07-08 22:27:26 +02:00
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modules/qualifying/learning_centralized_system_monitoring.md
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@ -22,9 +22,7 @@ When monitoring for example ten workstations or servers you will have **one** ma
![munin architecture](./assets/munin_architecture.png)
### First installation
#### The master
### The master
First we'll install one munin **master** for everybody in the classroom.
The installation documentation on the official [website](http://guide.munin-monitoring.org/en/latest/installation/install.html) is very good so we'll follow that one.
@ -34,7 +32,7 @@ The overall processes has three components.
2. configure the master to query some future nodes
3. install a web server to serve the monitor pages
##### Installing
#### Installing
Installing can be done through the Debian package manager.
Do a `tab-complete` to see all available packages and note that on the **master** you need the `munin` package.
@ -55,7 +53,7 @@ Why does the master also install the node?
Well, just so it can monitor itself and display it in the web gui.
This gives you already a good idea of what will need to be installed and configured on the nodes.
##### Configuring
#### Configuring
The main configuration file for munin is located at `/etc/munin/munin.conf`.
Open up your favorite text editor and browse through it.
@ -88,7 +86,7 @@ On my demonstration server the configuration is as follows.
For now we'll just leave it as is and move on to installing the web server.
##### The web server
#### The web server
Here you have a choice to make but any way you go, you can't really go wrong.
My web server of choice is often `nginx` and we'll install that one together because I'm most comfortable with it.
@ -165,7 +163,7 @@ Web servers are an essential part of any Linux system administrator's life.
**Can you figure out how to password protect this folder so it behaves like my munin server?**
#### The first node
### The first node
Let's add some nodes!
The nodes have to be in the same network in order to be contactable by the master.
@ -190,7 +188,33 @@ By default the node only accepts incoming connections from the localhost.
We can add as many **masters** as we like to this list but we must respect the regex syntax.
I'll leave that up to you to figure out.
#### Plugins
## Hints
Munin works with [plugins](https://guide.munin-monitoring.org/en/latest/plugin/use.html#plugin-use) to supply the master with data to plot.
You can install extra plugins or even write your own in [bash](https://guide.munin-monitoring.org/en/latest/develop/plugins/howto-write-plugins.html#howto-write-plugins) or in [python](https://aouyar.github.io/PyMunin/).
To have your node auto detect which plugins should be used you can execute the following command as root (not sudo).
```
munin-node-configure --shell --families=contrib,auto | sh -x
```
## Other operating systems
Because the munin server client model is so basic you can find node software for most operating systems.
I've run it successfully on [freeNAS](https://www.truenas.com/community/threads/install-munin-node.79224/#post-549934) but you can try a [windows](https://github.com/munin-monitoring/munin-node-win32) node as well.
## Alternatives
There are quite a few alternatives out there to choose from.
One of the better known is [nagios](https://www.nagios.org/) which can be installed on Debian as well.
There are ways to have munin and nagios work together that are described [here](https://guide.munin-monitoring.org/en/latest/tutorial/nagios.html?highlight=nagios).
## Notes and hints
You might feel munin is too simple or basic because it does not offer any tweaking via it's web GUI but that's the main reason why I *like* and use it so much.
Because it's so simple, it's not a real security risk.
I would however **not** expose a master to the internet without **SSL** and a good **htpasswd**.
There are some known exploits in the CGI part of munin.
* the Debian system administrator handbook has a good [section](https://debian-handbook.info/browse/stable/sect.monitoring.html#sect.munin) on munin
* if your dynamic zoom is not working have a look [here](https://serverfault.com/questions/615048/munin-dynamic-graph-zoom-dynazoom-not-working-nginx-php-fpm)