schleppe-lab/_posts/2023-05-19-kvm.markdown

---
layout: post
title:  Network KVM for ALL of my Servers!
date:   2023-05-19 15:46:15 +0200
updated: 2023-05-19 15:52:00 +0200
tags: networking virtualization
---

Since I use a lot of repurposed computers as servers, I don’t have many with IPMI / remote access built in. Usually I can configure them remotely through SSH or their web UI, but sometimes things go wrong and it’s nice to have remote console access. Enter, PiKVM, a project to build a networked KVM switch with a Raspberry Pi. Unfortunately, I have a more than one server, and building a PiKVM for every one gets expensive, so I’m combining it with an 8 port rack mount KVM switch so I can remotely view and control all of the servers in my rack.

The KVM I’m using supports network control (but it’s not a network KVM, it can just switch inputs over the network) and I’ve configured that in this video.

# Contents

- [Networking Configuration](#networking-configuration)
- [PiKVM Configuration](#pikvm-configuration)

# Networking Configuration

The network configuration goes in `/etc/systemd/network/eth0.network`. Make sure to run `rw` to make the filesystem writeable before editing it, and `ro` when you are done.

```
[Match]
Name=eth0

[Network]
DHCP=yes
DNSSEC=no
# Use DHCP for primary address
# Add a static address in a /31 for the TESmart KVM
Address=192.168.1.11/31


[DHCP]
# Use same IP by forcing to use MAC address for clientID
ClientIdentifier=mac
# https://github.com/pikvm/pikvm/issues/583
RouteMetric=10
```

# PiKVM Configuration

The PiKVM configuration override goes in `/etc/kvmd/override.yaml`. Make sure to run `rw` to make the filesystem writeable before editing it, and `ro` when you are done. I’m using the default IP of the Tesmart and a /31 subnet to avoid changing it, but if you do change the IP you’d change it here as well.

{% highlight ruby %}
def print_hi(name)
  puts "Hi, #{name}"
end
print_hi('Tom')
#=> prints 'Hi, Tom' to STDOUT.
{% endhighlight %}


<figure id="highlight-figure">
  <figcaption>File: folderName/fileName.rb</figcaption>
    {% highlight ruby %}
    def print_hi(name)
      puts "Hi, #{name}"
    end
    print_hi('Tom')
    #=> prints 'Hi, Tom' to STDOUT.
    {% endhighlight %}
</figure>


<figure id="highlight-figure">
  <figcaption>File: folderName/fileName.rb</figcaption>
{% highlight yaml linenos %}
kvmd:
    gpio:
        drivers:
            tes:
                type: tesmart
                host: 192.168.1.10
                port: 5000
        scheme:
            server0_led:
                driver: tes
                pin: 0
                mode: input
            server0_switch:
                driver: tes
                pin: 0
                mode: output
                switch: false
            server1_led:
                driver: tes
                pin: 1
                mode: input
            server1_switch:
                driver: tes
                pin: 1
                mode: output
                switch: false    
            server2_led:
                driver: tes
                pin: 2
                mode: input
            server2_switch:
                driver: tes
                pin: 2
                mode: output
                switch: false    
            server3_led:
                driver: tes
                pin: 3
                mode: input
            server3_switch:
                driver: tes
                pin: 3
                mode: output
                switch: false    
            server4_led:
                driver: tes
                pin: 4
                mode: input
            server4_switch:
                driver: tes
                pin: 4
                mode: output
                switch: false    
            server5_led:
                driver: tes
                pin: 5
                mode: input
            server5_switch:
                driver: tes
                pin: 5
                mode: output
                switch: false    
            server6_led:
                driver: tes
                pin: 6
                mode: input
            server6_switch:
                driver: tes
                pin: 6
                mode: output
                switch: false    
            server7_led:
                driver: tes
                pin: 7
                mode: input
            server7_switch:
                driver: tes
                pin: 7
                mode: output
                switch: false
        view:
            table:
                - ["TESMART Switch"]
                - []
                - ["#Terra NAS", server0_led, server0_switch|Switch]
                - ["#Megalab", server1_led, server1_switch|Switch]
                - ["#PVE1", server2_led, server2_switch|Switch]
                - ["#PVE2", server3_led, server3_switch|Switch]
                - ["#PVE3", server4_led, server4_switch|Switch]
                - ["#Minilab", server5_led, server5_switch|Switch]
                - ["#OPNsense", server6_led, server6_switch|Switch]
                - ["#Iridium",  server7_led, server7_switch|Switch]
{% endhighlight %}
</figure>


{% highlight yaml linenos %}
kvmd:
    gpio:
        drivers:
            tes:
                type: tesmart
                host: 192.168.1.10
                port: 5000
        scheme:
            server0_led:
                driver: tes
                pin: 0
                mode: input
            server0_switch:
                driver: tes
                pin: 0
                mode: output
                switch: false
            server1_led:
                driver: tes
                pin: 1
                mode: input
            server1_switch:
                driver: tes
                pin: 1
                mode: output
                switch: false    
            server2_led:
                driver: tes
                pin: 2
                mode: input
            server2_switch:
                driver: tes
                pin: 2
                mode: output
                switch: false    
            server3_led:
                driver: tes
                pin: 3
                mode: input
            server3_switch:
                driver: tes
                pin: 3
                mode: output
                switch: false    
            server4_led:
                driver: tes
                pin: 4
                mode: input
            server4_switch:
                driver: tes
                pin: 4
                mode: output
                switch: false    
            server5_led:
                driver: tes
                pin: 5
                mode: input
            server5_switch:
                driver: tes
                pin: 5
                mode: output
                switch: false    
            server6_led:
                driver: tes
                pin: 6
                mode: input
            server6_switch:
                driver: tes
                pin: 6
                mode: output
                switch: false    
            server7_led:
                driver: tes
                pin: 7
                mode: input
            server7_switch:
                driver: tes
                pin: 7
                mode: output
                switch: false
        view:
            table:
                - ["TESMART Switch"]
                - []
                - ["#Terra NAS", server0_led, server0_switch|Switch]
                - ["#Megalab", server1_led, server1_switch|Switch]
                - ["#PVE1", server2_led, server2_switch|Switch]
                - ["#PVE2", server3_led, server3_switch|Switch]
                - ["#PVE3", server4_led, server4_switch|Switch]
                - ["#Minilab", server5_led, server5_switch|Switch]
                - ["#OPNsense", server6_led, server6_switch|Switch]
                - ["#Iridium",  server7_led, server7_switch|Switch]
{% endhighlight %}