State of the Homelab
Published: September 12, 2022
I've been sinking some time recently into organizing my homelab, spurred by the recent addition of a NAS, and thought it might be a good time to write about it.
Birds Eye View
Here's the network topology:
┌──────────────┐ ┌───────┐ │ Wifi Clients │ │ Wired │ └──────────────┘ │Clients│ : └───┬───┘ : │ ┌───────▼───────┐ ┌────▼─────┐ Internet │ Verizon ├────► OpenBSD │ ─────────► Router │ │ Router │ │ (FiosGateway) ◄────┤ (apu2e4) │ └──────┬──▲─────┘ └──┬───▲───┘ │ │ │ │ ┌───▼──┴──┐ ┌───▼───┴────┐ │ pi.hole │ │ NAS/Git │ │ (Rpi4b) │ │(Odroid HC4)│ └─────────┘ └────────────┘
Excluding the Fios router, that's 3 servers hosting the following services:
- A git server for private repos (public repos hosted on git.alexkarle.com, and sourcehut).
- A NAS (network attached storage) for backups, photos, music, etc
- A network wide ad-blocker (pi-hole)
- An OpenBSD router/firewall (dhcp / pf) to provide extra security to my wired devices.
Why Bother with a Homelab, Anyways?
Before I dive into each component, I want to take a step back and ask why.
In a world where you can pay
$HIP_COMPANY $5/mo to
run or host anything, it may seem like a homelab
is a waste of time and effort. Looking at what I'm running,
a lot of it could even be hosted for free!
Despite the time cost of tending to this digital garden, I've found that running my homelab has been an incredible source of learning from hands-on experimentation. At this stage in my career, this type of experience is invaluable, especially because a lot of it (hardware tinkering, sysadmin tasks, linux distros, etc) doesn't come across my desk often.
As an added bonus, I really enjoy the feeling of digital ownership I get from hosting my private data. It certainly comes with the weight of responsibility that I need to keep (and test!) backups, but the learning and ownership feel worthwhile for now.
The Nitty Gritty
I have no special attachment to Verizon--I wouldn't go so far as to endorse them, but my coworkers don't complain about lag during video calls, so I haven't mustered the courage to switch providers.
It's on my long todo list to switch to a more local ISP, but with both me and my fiance working from home it's the last place I want an outage.
Pi-hole is a network wide adblocker. It works by acting as the DNS server for your network and responding with localhost (0.0.0.0) for known spammy domains.
As a concrete example, with pi-hole running right now, I can't access doubleclick.net (Google ads):
# Response from my router $ host doubleclick.net 192.168.1.1 Using domain server: Name: 192.168.1.1 Address: 192.168.1.1#53 Aliases: doubleclick.net has address 0.0.0.0 doubleclick.net has IPv6 address :: # Response from Google's DNS resolver $ host doubleclick.net 192.168.1.1 Using domain server: Name: 188.8.131.52 Address: 184.108.40.206#53 Aliases: doubleclick.net has address 220.127.116.11 [...]
The default configuration for the Gateway router is to tell clients to use it (192.168.1.1) as a DNS server. By updating Gateway to use pi-hole as it's server (instead of the Verizon supplied ones), all clients on the network receive pi-hole's filtering.
What's brilliant about this is that no clients need updating. As far as they're aware, they really are trying to reach out to doubleclick.net. It's just a network failure that 0.0.0.0 isn't listening on 443!
The results are most noticeable on mobile since I use uBlock Origin on all my browsers. It's amazing how much faster and less cluttered certain mobile apps are without ads (cough nytimes cough please stop it with the full screen banners).
Finally, as the name might imply, the pi-hole was designed to run on the Raspberry Pi. I'm running mine on a Raspberry Pi 4b, which is definitely overkill for the resources it needs.
Running a private git server is incredibly easy. In fact, there isn't really any separate git daemon that needs running. So long as you have ssh access to the host, you can clone/push/pull from:
$ git clone user-on-host@host:/path/to/server
I like to get a bit fancy and
git user on the server so
that the repos can be stored in its home directory and ssh access can
be managed separately from the user account I would normally use.
git user has the home directory
/home/git, the following
$ git clone git@host:repo.git
A lot more detail, including securing the git user by assigning it the
git-shell for the login shell, can be found in the amazing
As far as what I keep on my personal server (that I wouldn't trust to sourcehut, or even really my own git.alexkarle.com), I host the following repos:
My password repository (for
- Personal notes (public notes go on gopher://alexkarle.com/1/notes!)
In the past (mostly for fun), I've hosted cgit, gitea and even GitLab (reverse chronologically and also least to most heavy). I've found that for the few private repos I host, I rarely want a web UI (let alone forking/user accounts/etc).
The most recent upgrade to my homelab was the addition of a purpose-built NAS using the Odroid HC4 toaster-style dual hard drive board.
Previously, my backups were distributed across multiple drives and frequently offline (with all my operating system tinkering I have 5 SSD's of which only 2 are in use at any time...). Things that I needed frequent access to were stored on a (rather fragile) Raspberry Pi 3b on a 64GB thumbdrive! Needless to say, the HC4 is a step up.
It's only really been online for ~24hrs so I don't have a solid review of the hardware yet, but initial impressions are:
- I was a bit bummed that the Linux they support is an old forked kernel, which strikes me as probably missing security patches (didn't poke around hard enough to confirm though--it may be up to date and just old!)
- Despite being on the OpenBSD hardware list, I couldn't get it to boot. Given the need to unscrew the plastic top to get the UART serial connection in, I stopped trying after a few hours :(. I might email the mailing list in the future to see what I overlooked.
- I was pleased to find that the Armbian project supported it (with a newer kernel!). This is what I ended up installing (with no issues so far)
- I stumbled across Chandler Swift's awesome writeup about his experience with the HC4 and his golang odroidhc4-display tool is the perfect easy-to-deploy service for the little display
Overall, operating system quirks aside, I'm really happy with how it turned
out. I put in two 2TB western digital drives (whatever BestBuy had on sale
a few weekends ago) and encrypted both of them with
cryptsetup using the
LUKS encryption mode as described in the
I intentionally did not RAID-1 the drives together because I'm more worried
rm-ing a file than I am not having access to the data
in case of drive failure. Instead, I have only one drive always online. A
cron job mounts the offline drive daily,
rsync's over the data, and
unmounts it when done. This should give me hopefully a few hours or more
if I realize I deleted a file. (I'll eventually also cycle in a third drive
for offsite storage somewhere trusted like my parents' house).
In the future I'd love to use this NAS as an excuse to explore fancier filesystems like ZFS, but I stuck to ext4 for now.
Puts tinfoil hat on.
The final piece of the topology is maybe the least functional in terms of hosting required services but the best learning tool: the OpenBSD router.
There are arguably some security wins here by bisecting my network between wifi and wired clients. For one, the Verizon router itself may or may not be receiving security patches (it's proprietary, who knows?). By setting up a firewall so that the only traffic going in to wired clients is the traffic expected, the wired clients are a tad safer.
While the security angle is certainly appealing, the much bigger reason
to have this in my homelab has been experimenting with router technologies.
In setting this up I had to grok
pf (packet filtering for the firewall),
dhcpd (to give clients IP addresses), and just basic networking
(how does a machine in one network talk to another?). There's no better
way to learn networking than having my wifi laptop trying to ping my
wired desktop and
tcpdumping the traffic.
This is running on a PC Engines apu2e4, mostly since it seemed popular with the community and I wanted to make sure the device had good OpenBSD support. It's been running since April 2021 without issues, so I'd recommend it!
I would eventually love to write my own pi-hole using the DNS tools in base, but for now it's low on my todo list.
If you made it this far, thanks! I hope you learned something or found something of interest.
I'll hopefully write a similar "state of the cloud" post to cover the services I'm running outside home, but I think this post might just be long enough for now :)
Update: State of the Cloud post has been written!