Show HN: Kula – Lightweight, self-contained Linux server monitoring tool

Posted by c0m4r 3 days ago

Zero dependencies. No external databases. Single binary. Just deploy and go. I needed something that would allow for real-time monitoring, and installation is as simple as dropping a single file and running it. That's exactly what Kula is. Kula is the Polish word for "ball," as in "crystal ball." The project is in constant development, but I'm already using it on multiple servers in production. It still has some rough edges and needs to mature, but I wanted to share it with the world now—perhaps someone else will find it useful and be willing to help me develop it by testing or providing feedback. Cheers! Github: https://github.com/c0m4r/kula

Comments

Comment by savalione 3 days ago

Is there any meaningful reason to add the project structure to the README, and add a copyright symbol to every mention of Linux? I'm not quite sure by what standards it's considered to be lightweight, but it may be useful for homelab owners.

Anyway, Zabbix still looks like a better solution by any metric.

Comment by c0m4r 3 days ago

I got your point. The project structure remains from the initial phase of building the tool. I think I'll eventually remove it or put it on the wiki or somewhere else. My excessive attachment to copyright probably stems from the fact that years ago, when I wrote my own websites and articles, people often simply copied them and signed them as their own. The Linux Foundation website has attribution instructions that ask for the use of the ® symbol; I simply followed this instruction, but I agree that it's probably an exaggeration on my part. Considering what this tool does, I personally think it's lightweight in terms of both binary size, execution times, and dashboard performance. But I agree that's debatable.

Comment by dqv 3 days ago

In fact, you followed the instructions exactly to spec https://www.linuxfoundation.org/legal/the-linux-mark

Comment by sirpilade 2 days ago

I think that having the « How it works » section in the README makes the aim of the project a lot easier to understand

Comment by sneak 3 days ago

I like having tons of docs in the README, vertical screen space is cheap.

Comment by mervz 3 days ago

The README was AI generated, that's why.

Comment by ramon156 3 days ago

Ironically, Zabbix front page also has some AI smells. Doesn't really matter regarding the actual tool, which is indeed more battle-tested

Comment by c0m4r 3 days ago

Initially, yes. However since then I edit it manually, but I agree it still has the AI vibe. I'll work on that!

Comment by sneak 3 days ago

> Kula uses Argon2id for password hashing. If you enable authentication, it is highly recommended to tune the Argon2 parameters (time, memory, threads) in config.yaml based on your hardware capabilities to increase resistance against cracking.

There is no reason to do this. Set them to sane defaults and set a minimum password length of 12 or 14 chars and stop trying to solve the wrong problem.

Comment by planb 3 days ago

Honestly the sentence from the readme just sounds like a recommendation an LLM would make.

Comment by c0m4r 3 days ago

It is from LLM and some of the security features are overkill - I'm aware of that. These will be optional. I will also try to improve the readability of the README and move more detailed documentation to the wiki. Thanks for your opinions!

Comment by plagiat0r 2 days ago

Back in the 90/2000 the was a very popular tool named rrdtool to store metrics in a round robin structure on disk, especially suited for network metrics. The goal of the storage was to have a fixed size and cover only last NNN days, circularly.

I use rrdtool to this day, as a building block, but this project looks much better.

Comment by c0m4r 2 days ago

Oh rrdtool is still relevant today. Multiple (if not most of) monioring tools like Cacti, Observium, Munin still use it.

Comment by mattjoyce 2 days ago

I still use it. A few months ago I whipped up a project to monitor my Unraid NAS. Rrdtool is very useful still.

Comment by debarshri 2 days ago

rrdtool conbined with graphite was powerful back then when metrics and logging was selfhosted.

Comment by mitjam 3 days ago

I like that you've started keeping your prompts in the repo [1]. Why have you deleted them, later on? What I find curious is how can something AI generated can be licensed AGPL?

[1]: https://github.com/c0m4r/kula/commit/ae3f8a8483c91fe8bd4ea2c...

Comment by c0m4r 3 days ago

At some point, writing these files became a hassle and I felt it was too chaotic, so I gave up on it. Regarding licenses, given that LLMs are using other people's work without their consent anyway, and most of the code produced rn is AI, these licenses are to me really just suggestions. I would treat them as an expression of intent, not a strictly legal document.

Comment by danparsonson 3 days ago

It would be interesting to hear a lawyer's take on that, as I suspect their opinion might differ from yours...

Comment by c0m4r 3 days ago

A lawyer's opinion will be directly proportional to their fee and will have little to do with reality, because the law hasn't kept up with what's happening right now. If you don't code with AI, you'll be left behind. Everyone is coding with AI, even in places where it's not immediately obvious, there's AI. You open the refrigerator and AI comes out. I don't know how this will be regulated, I'm not an expert in this field, but for now, it is what it is. The most important thing for me is that I don't derive any financial benefit from this and I give attribution where it is due.

Comment by danparsonson 2 days ago

No, a lawyers opinion will reflect the law. From a legal standpoint it doesn't matter how you feel about applying a license to your work, it matters what the law says about that. I'm not a lawyer, but my expectation is that the license you choose will bind anyone who chooses to use your software, and in particular will have an effect on companies that wish to use it. That may be fine and exactly what you want, but my point is just that it's not necessarily a whimsical 'statement of intent'.

Comment by mitjam 3 days ago

I feel that too :) With the license, you are right, and I like your stance of "expressed intent".

Comment by c0m4r 3 days ago

I've uploaded these prompts to the repo's wiki if anyone else would like to read my broken English.

Comment by amar0c 3 days ago

Monitoring needs to be: single dashboard << many agents. I have no plan deploying dashboard on every server.

Comment by c0m4r 3 days ago

I think netdata or Grafana with a chosen backend is right for you then. My goal was different, but I'll consider implementing such functionality in the long run. Thank you for your feedback.

Comment by smashed 3 days ago

Vibe coded netdata clone?

Comment by c0m4r 3 days ago

Yes, netdata was an inspiration, as I'd been using it for several years. Unfortunately, it stopped being what it initially was, and recently I was so disappointed that I decided to write my own tool. It's also true that I use AI models for coding, but I wouldn't exactly call it vibe coding, as I actively analyze what the models are doing and don't just blindly accept everything. I also try to thoroughly test my code, implement as many security-enhancing features as possible, and have multiple models review my code to catch as many bugs as possible.

Comment by krautsauer 3 days ago

netdata is pretty heavy on resources, especially disk writes. I'd appreciate improvement over it, but I won't try out this thing without indication that it improves anything. Especially with such useful features as space invaders built in…

Comment by bityard 3 days ago

It's a bit ironic (in the Alanis Morrisette sense) because NetData was built by a small community on Reddit to be small, lightweight, easy to deploy, open source, etc. Now it looks like any other commercial enterprise monitoring product.

Comment by c0m4r 3 days ago

exactly this

Comment by c0m4r 3 days ago

That's fair. I can't resist putting easter eggs in my software, sorry :)

Comment by atmanactive 3 days ago

Reading through supported metrics, I don't see temperatures mentioned. That's really important for homelab servers. CPU temp, SSD temp, NVMe temp...

Comment by c0m4r 3 days ago

Temperatures monitoring will be added. Initially, I implemented too many metrics, so during development I limited them to a reasonable level to make them manageable, but I'll be adding more as the project matures. Thanks for the feedback!

Comment by atmanactive 3 days ago

Looking forward, thanks!

Comment by c0m4r 3 days ago

If you have a moment, I would be grateful if you could create an issue on github. I will then be able to let you know when it's ready and ask you to try it out. Please also let me know which temperatures you'd like to primarily monitor. I assume I'll have to gradually introduce the supported ones, as not all of them can be detected at once.

Comment by atmanactive 3 days ago

Sure thing. In my experiences based on using LibreHardwareMonitor [1] on Windows, and Dunnart [2] on Linux, dealing with temperature monitoring is not trivial. But it's not impossible either. For example, in Linux, looking at /sys folder for CPU temperatures, I can often find several entries, of which, some are dead, some are way off, and some are correct, but it is always a hit and miss endeavour. So, reliably monitoring temperatures requires a bit of an algorithm to detect the right source.

[1] https://github.com/LibreHardwareMonitor/LibreHardwareMonitor

[2] https://github.com/warthog618/dunnart

Comment by c0m4r 3 days ago

That's true, which is why I assume I'll have to gradually implement this feature. It probably won't be perfect, but it's worth trying :)

Thank you for opening the issue!

Comment by smashed 3 days ago

Most (all?) temperature monitoring tools on Linux rely on libsensors.

Seems like hardware maintainers never could agree on a standard way of exposing temperature on Linux.

Comment by c0m4r 3 days ago

Yeah, that's a pain. Every time I boot up new hardware, I wonder how many readings I'll be able to get this time, and if it's even possible. On one computer, I have practically all the temperatures, voltages, and fan speeds, while on another, I can barely read the CPU temperature alone. Not to mention the need to sometimes compile sketchy drivers from github...

Comment by kulahan 3 days ago

I'm very curious where you got the inspiration for the name for this! I've been using Kula/Kulahan as a username for years and almost never see it anywhere else

Comment by c0m4r 3 days ago

Well, it was easy since my native language is Polish and I often use "kula szpiegula" term, which translates to something like a "spying crystal ball" in relation to things that allow monitoring or collecting information. In Polish, "kula" can refer to many things, e.g. a sphere or a globe.

Comment by kulahan 2 days ago

TIL, that’s awesome. Thanks very much

Comment by doug_life 3 days ago

dash. (or dashdot) https://github.com/MauriceNino/dashdot is another alternative that is pretty lightweight but has fewer details. Live Demo: https://dash.mauz.dev

Comment by c0m4r 3 days ago

Nice little panel. Although a bit too kawaii for my taste!

Comment by mastermage 3 days ago

This might be nice for my vps. May i ask if there is a way to see the resources per docker container?

Comment by c0m4r 3 days ago

I'm not currently collecting metrics for containers. Though I might add this feature later on.

Comment by reacharavindh 3 days ago

On these lines… it has been on my “to be vibe-coded” list to make an extremely minimal node-exporter(the metrics collector for Prometheus) in rust (support only Linux, gather extremely minimal set of metrics) that uses tightly controlled concurrency so as to fetch all metrics within a short span of time.

If anyone has more AI tokens or spare time with mental energy to burn… go for it :-)

Comment by c0m4r 3 days ago

I think that once I get most of the core functions stable, I will also want to add options for exporting metrics.

Comment by thebuilderjr 3 days ago

[flagged]

Comment by c0m4r 3 days ago

Netdata was actually THE reason I wanted to create my own real-time monitoring system. When I first came across Netdata, it was everything I needed, and its dashboard was fast, clean, and easy to use. But ever since they created the v3 dashboard and started aggressively advertising their cloud services, it became off-putting to me. Thank you for your suggestions, noted!

Comment by sneak 3 days ago

Why the nonfree AGPL? Are you seriously worried that someone is going to fork this and make money with it, given that anyone else could vibe code another one in a few hours?

Comment by yjftsjthsd-h 3 days ago

> Why the nonfree AGPL?

By no reasonable definition is AGPL nonfree. It isn't a permissive license, but it's libre, gratis, and open source.

> given that anyone else could vibe code another one in a few hours?

If that's true, then who cares?

Comment by c0m4r 3 days ago

To be honest, I didn't think about it for too long. I choose licenses based on intuition. I put a lot of work into this tool, I knew it would require a lot of effort, and besides, I created it precisely because someone else turned a similar project into a money-making machine, completely abandoning the original ideals. Therefore, I felt that AGPL, which requires code disclosure and non-profit use, is the way to go.

Comment by smashed 3 days ago

Yes. Besides AGPL makes a lot of sense for any web based tool, as it keeps the original intent of the GPL.

I don't get the hate/questioning on it either. It's a good balance if you want to prevent straight up cloning/stealing for profit motives while still making it open.

Comment by koiueo 3 days ago

1. Why do you ask? Do you intend forking and making money out of it?

2. Why are you lying about AGPL being nonfree? As far as I'm concerned, it is free as in free speech for me as a user. This was the initial goal of the GPL. The freedom of the end user is the main value of the GPL family of licenses. So serious question: why are you lying? Is it intentional, or due to your lack of understanding?

Comment by sneak 3 days ago

Re 1: No, I don’t run paid internet services, only free ones. I just think it’s silly when people distribute software and pretend it’s free software but slap an anti-commercial-use EULA on it.

Not lying: The AGPL plainly violates freedom 0.

https://sneak.berlin/20250720/the-agpl-is-nonfree/

Comment by c0m4r 3 days ago

I respect your opinion, but I disagree with it. It's purely a matter of perspective. I find such restrictions acceptable in free licenses. Besides, as you pointed out, these licenses don't matter anyway, since anyone can use AI and write their own tool :) This choice of license is just my suggestion, or if you prefer, a manifesto that I don't want open source projects to become closed source, that's all.

Comment by koiueo 3 days ago

Your initial question had your ungrounded assumption/opinion embedded in it. I did the same to you. Not the thing I usually do.

Your reasoning has plenty of strawman arguments and opinions. Starting from SaaS is not software, to how AGPL is impossible to comply with, because when you commit, the source goes out of sync with the running code.

IMO you still miss the point of GPL: it's to protect users.

As soon as you start offering your software (as a service or otherwise), you become a vendor. AGPL then is not for you, it's for users you're serving.

Finally, to enforceability. The only enforceable laws in our world have always been laws of physics. Everything else is a social construct, which, depending on your social status and immediate surrounding, applies to you at various degrees (sometimes not at all). All the laws produced by society only align our common expectations, but none is absolutely enforceable.

IMO, AGPL is the best idealistic scenario for end users. And society would only win if the expectations set by AGPL became the norm.

// Typed from my phone