f3s: Kubernetes with FreeBSD - Part 2: Hardware and base installation

Published at 2024-12-02T23:48:21+02:00

This is the second blog post about my f3s series for my self-hosting demands in my home lab. f3s? The "f" stands for FreeBSD, and the "3s" stands for k3s, the Kubernetes distribution I will use on FreeBSD-based physical machines.

We set the stage last time; this time, we will set up the hardware for this project.

These are all the posts so far:

2024-11-17 f3s: Kubernetes with FreeBSD - Part 1: Setting the stage
2024-12-03 f3s: Kubernetes with FreeBSD - Part 2: Hardware and base installation (You are currently reading this)

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Let's continue...

f3s: Kubernetes with FreeBSD - Part 2: Hardware and base installation
Deciding on the hardware
⇢ Not ARM but Intel N100
⇢ Beelink unboxing
⇢ Network switch
Installing FreeBSD
⇢ Base install
⇢ Latest patch level and customizing /etc/hosts
⇢ After install
⇢ ⇢ Helix editor
⇢ ⇢ doas
⇢ ⇢ Periodic ZFS snapshotting
⇢ ⇢ Uptime tracking
Hardware check
⇢ Ethernet
⇢ RAM
⇢ CPUs
⇢ CPU throttling
Conclusion

Deciding on the hardware

Note that the OpenBSD VMs included in the f3s setup (which will be used later in this blog series for internet ingress - as you know from the first part of this blog series) are already there. These are virtual machines that I rent at OpenBSD Amsterdam and Hetzner.

https://openbsd.amsterdam
https://hetzner.cloud

This means that the FreeBSD boxes need to be covered, which will later be running k3s in Linux VMs via bhyve hypervisor.

I've been considering whether to use Raspberry Pis or look for alternatives. It turns out that complete N100-based mini-computers aren't much more expensive than Raspberry Pi 5s, and they don't require assembly. Furthermore, I like that they are AMD64 and not ARM-based, which increases compatibility with some applications (e.g., I might want to virtualize Windows (via bhyve) on one of those, though that's out of scope for this blog series).

Not ARM but Intel N100

I needed something compact, efficient, and capable enough to handle the demands of a small-scale Kubernetes cluster and preferably something I don't have to assemble a lot. After researching, I decided on the Beelink S12 Pro with Intel N100 CPUs.

Beelink Mini S12 Pro N100 official page

The Intel N100 CPUs are built on the "Alder Lake-N" architecture. These chips are designed to balance performance and energy efficiency well. With four cores, they're more than capable of running multiple containers, even with moderate workloads. Plus, they consume only around 8W of power (ok, that's more than the Pis...), keeping the electricity bill low enough and the setup quiet - perfect for 24/7 operation.

The Beelink comes with the following specs:

12th Gen Intel N100 processor, with four cores and four threads, and a maximum frequency of up to 3.4 GHz.
16 GB of DDR4 RAM, with a maximum (official) size of 16 GB (but people could install 32 GB on it).
500 GB M.2 SSD, with the option to install a 2nd 2.5 SSD drive (which I want to make use of later in this blog series).
GBit ethernet
Four USB 3.2 Gen2 ports (maybe I want to mount something externally at some point)
Dimensions and weight: 115*102*39mm, 280g
Silent cooling system.
HDMI output (needed only for the initial installation and maybe for troubleshooting later)
Auto power on via WoL (may make use of it)
Wi-Fi (not going to use it)

I bought three (3) of them for the cluster I intend to build.

Beelink unboxing

Unboxing was uneventful. Every Beelink PC came with:

An AC power adapter
An HDMI cable
A VESA mount with screws (not using it as of now)
Some manuals
The pre-assembled Beelink PC itself.
A "Hello" post card (??)

Overall, I love the small form factor.

Network switch

I went with the tp-link mini 5-port switch, as I had a spare one available. That switch will be plugged into my wall ethernet port, which connects directly to my fiber internet router with 100 Mbit/s down and 50 Mbit/s upload speed.

Installing FreeBSD

Base install

First, I downloaded the boot-only ISO of the latest FreeBSD release and dumped it on a USB stick via my Fedora laptop:

[paul@earth]~/Downloads% sudo dd \
  if=FreeBSD-14.1-RELEASE-amd64-bootonly.iso \
  of=/dev/sda conv=sync

Next, I plugged the Beelinks (one after another) into my monitor via HDMI (the resolution of the FreeBSD text console seems strangely stretched, as I am using the LG Dual Up monitor), connected Ethernet, an external USB keyboard, and the FreeBSD USB stick, and booted the devices up. With F7, I entered the boot menu and selected the USB stick for the FreeBSD installation.

The installation was uneventful. I selected:

Guided ZFS on root (pool zroot)
Unencrypted ZFS (I will encrypt separate datasets later; I want it to be able to boot without manual interaction)
Static IP configuration (to ensure that the boxes always have the same IPs, even after switching the router/DHCP server)
I decided to enable the SSH daemon, NTP server, and NTP time synchronization at boot, and I also enabled powerd for automatic CPU frequency scaling.
In addition to root, I added a personal user, paul, whom I placed in the wheel group.

After doing all that three times (once for each Beelink PC), I had three ready-to-use FreeBSD boxes! Their hostnames are f0, f1 and f2!

Latest patch level and customizing /etc/hosts

After the first boot, I upgraded to the latest FreeBSD patch level as follows:

root@f0:~ # freebsd-update fetch
root@f0:~ # freebsd-update install
root@f0:~ # freebsd-update reboot

I also added the following entries for the three FreeBSD boxes to the /etc/hosts file:

root@f0:~ # cat <<END >>/etc/hosts
192.168.1.130 f0 f0.lan f0.lan.buetow.org
192.168.1.131 f1 f1.lan f1.lan.buetow.org
192.168.1.132 f2 f2.lan f2.lan.buetow.org
END

After install

After that, I installed the following additional packages:

root@f0:~ # pkg install helix doas zfs-periodic uptimed

Helix editor

Helix? It's my favourite text editor. I have nothing against vi but like hx (Helix) more!

https://helix-editor.com/

doas

doas? It's a pretty neat (and KISS) replacement for sudo. It has far fewer features than sudo, which is supposed to make it more secure. Its origin is the OpenBSD project. For doas, I accepted the default configuration (where users in the wheel group are allowed to run commands as root):

root@f0:~ # cp /usr/local/etc/doas.conf.sample /usr/local/etc/doas.conf

https://man.openbsd.org/doas

Periodic ZFS snapshotting

zfs-periodic is a nifty tool for automatically creating ZFS snapshots. I decided to go with the following configuration here:

root@f0:~ # sysrc daily_zfs_snapshot_enable=YES
daily_zfs_snapshot_enable:  -> YES
root@f0:~ # sysrc daily_zfs_snapshot_pools=zroot
daily_zfs_snapshot_pools:  -> zroot
root@f0:~ # sysrc daily_zfs_snapshot_keep=7
daily_zfs_snapshot_keep:  -> 7
root@f0:~ # sysrc weekly_zfs_snapshot_enable=YES
weekly_zfs_snapshot_enable:  -> YES
root@f0:~ # sysrc weekly_zfs_snapshot_pools=zroot
weekly_zfs_snapshot_pools:  -> zroot
root@f0:~ # sysrc weekly_zfs_snapshot_keep=5
weekly_zfs_snapshot_keep:  -> 5
root@f0:~ # sysrc monthly_zfs_snapshot_enable=YES
monthly_zfs_snapshot_enable:  -> YES
root@f0:~ # sysrc monthly_zfs_snapshot_pools=zroot
monthly_zfs_snapshot_pools:  -> zroot
root@f0:~ # sysrc monthly_zfs_snapshot_keep=6
monthly_zfs_snapshot_keep: 2 -> 6

https://github.com/ross/zfs-periodic

Uptime tracking

uptimed? I like to track my uptimes. This is how I configured the daemon:

root@f0:~ # cp /usr/local/mimecast/etc/uptimed.conf-dist \
  /usr/local/mimecast/etc/uptimed.conf 
root@f0:~ # hx /usr/local/mimecast/etc/uptimed.conf

In the Helix editor session, I changed LOG_MAXIMUM_ENTRIES to 0 to keep all uptime entries forever and not cut off at 50 (the default config). After that, I enabled and started uptimed:

root@f0:~ # service uptimed enable
root@f0:~ # service uptimed start

To check the current uptime stats, I can now run uprecords:

 root@f0:~ # uprecords
     #               Uptime | System                                     Boot up
----------------------------+---------------------------------------------------
->   1     0 days, 00:07:34 | FreeBSD 14.1-RELEASE      Mon Dec  2 12:21:44 2024
----------------------------+---------------------------------------------------
NewRec     0 days, 00:07:33 | since                     Mon Dec  2 12:21:44 2024
    up     0 days, 00:07:34 | since                     Mon Dec  2 12:21:44 2024
  down     0 days, 00:00:00 | since                     Mon Dec  2 12:21:44 2024
   %up              100.000 | since                     Mon Dec  2 12:21:44 2024

This is how I track the uptimes for all of my host:

Unveiling guprecords.raku: Global Uptime Records with Raku-
https://github.com/rpodgorny/uptimed

Hardware check

Ethernet

Works. Nothing eventful, really. It's a cheap Realtek chip, but it will do what it is supposed to do.

paul@f0:~ % ifconfig re0
re0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
        options=8209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC,LINKSTATE>
        ether e8:ff:1e:d7:1c:ac
        inet 192.168.1.130 netmask 0xffffff00 broadcast 192.168.1.255
        inet6 fe80::eaff:1eff:fed7:1cac%re0 prefixlen 64 scopeid 0x1
        inet6 fd22:c702:acb7:0:eaff:1eff:fed7:1cac prefixlen 64 detached autoconf
        inet6 2a01:5a8:304:1d5c:eaff:1eff:fed7:1cac prefixlen 64 autoconf pltime 10800 vltime 14400
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
        nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>

RAM

All there:

paul@f0:~ % sysctl hw.physmem
hw.physmem: 16902905856

CPUs

They work:

paul@f0:~ % sysctl dev.cpu | grep freq:
dev.cpu.3.freq: 705
dev.cpu.2.freq: 705
dev.cpu.1.freq: 604
dev.cpu.0.freq: 604

CPU throttling

With powerd running, CPU freq is dowthrottled when the box isn't jam-packed. To stress it a bit, I run ubench to see the frequencies being unthrottled again:

paul@f0:~ % doas pkg install ubench
paul@f0:~ % rehash # For tcsh to find the newly installed command
paul@f0:~ % ubench &
paul@f0:~ % sysctl dev.cpu | grep freq:
dev.cpu.3.freq: 2922
dev.cpu.2.freq: 2922
dev.cpu.1.freq: 2923
dev.cpu.0.freq: 2922

Idle, all three Beelinks plus the switch consumed 26.2W. But with ubench stressing all the CPUs, it went up to 38.8W.

Conclusion

The Beelink S12 Pro with Intel N100 CPUs checks all the boxes for a k3s project: Compact, efficient, expandable, and affordable. Its compatibility with both Linux and FreeBSD makes it versatile for other use cases, whether as part of your cluster or as a standalone system. If you’re looking for hardware that punches above its weight for Kubernetes, this little device deserves a spot on your shortlist.

To ease cable management, I need to get shorter ethernet cables. I will place the tower on my shelf, where most of the cables will be hidden (together with a UPS, which will also be added to the setup).

What will be covered in the next post of this series? Maybe ttttbhyve/Rocky Linux and WireGuard setup as described in part 1 of this series...

Other *BSD-related posts:

2016-04-09 Jails and ZFS with Puppet on FreeBSD
2022-07-30 Let's Encrypt with OpenBSD and Rex
2022-10-30 Installing DTail on OpenBSD
2024-01-13 One reason why I love OpenBSD
2024-04-01 KISS high-availability with OpenBSD
2024-11-17 f3s: Kubernetes with FreeBSD - Part 1: Setting the stage
2024-12-03 f3s: Kubernetes with FreeBSD - Part 2: Hardware and base installation (You are currently reading this)

E-Mail your comments to paul@nospam.buetow.org :-)

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