Old school self hoster: scared of the security challenges of modern hosting
Old school self hoster: scared of the security challenges of modern hosting
TL;DR: old guy wants logs and more security in docker settings. Doesn’t want to deal with the modern world.
I’m on the sh.itjust.works lemmy instance. I don’t know how to reference another community thread so that it works for everyone, so my apologies for pointing at sh.itjust.works, but my thoughts here are inspired by https://sh.itjust.works/post/54990 and my attempts to set up a Lemmy server.
I’m old school. I’m in my mid-50’s. I was in academia as a student and then an employee from the mid-80’s through most of the 90’s. I’ve been in IT in the private sector since the late 90’s.
That means I was actively using irc and Usenet before http existed. I’ve managed publically facing mail and web servers in my job since the 90’s. I’ve run personal mail and web servers since the early 00’s. I even had a static HTML page that was the number one Google hit for an obscure financial search term for much of the 2000’s. The referer ip’s and search terms could probably have been mined for data.
On the work side, I’ve seen multiple email account compromises. (I’d note zero when it was on premise Lotus Notes. All of the compromises were after moving to O365. Those stopped for years once we moved to MFA, but this year we’ve seen two where the bad actors were able to MitM MFA. That said I don’t regret no longer supporting an on-prem Domino server: https://m.youtube.com/watch?v=Bk1dbsBWQ3k )
I’ve also seen a sophisticated vendor typo squatting email, combined with an internal email compromise cost us significant cash.
Other than email compromise, I’m not aware of any other intrusions. (There are two kinds of companies: those that know they’ve been hacked and those that don’t). I am friends with some IT people in a company where they were ransomwared. I still believe they have a tighter security stack than we do.
I’m paranoid about security because like Farmer’s I’ve seen a thing or two. We keep logs for a year, dumped into a SIEM that is designed to make it unlikely bad actors can get into it even if they take over A/D or VMWare. My home logging is less secure but still extensive. The idea is even if I’m hit, I hope I have the logs to help me understand how and how extensively.
I still have public websites at home, but they don’t contain any content that matters. The only traffic they see is attack attempts and indexers that will index them and then shove them down into oblivion. I’m fine with that.
I still run a mail server at home. It’s mostly used so all my unique email addresses ([email protected]) can get forwarded to my personal O365 instance. If I need to reply using a unique address, I use alpine in an ssh session.
Long prolog to explain my experience playing with a Lemmy instance this weekend. I’ve got an xcp-ng instance in the home lab and used it to get a Lemmy docker instance running. It’s not yet exposed to the outside world.
I’m new to docker. I’m new to Lemmy. I’m new to Nginx. (See the “old school” in the title.). At work and at home, I deal with Apache. I’ve got custom mod_rewrite rules and mod_security in place to deal with many attacks. I’m comfortable dealing with the tweaks on both for websites that break because of some rules.
I’ve tried putting an Apache proxy in front of my xcp-ng Lemmy instance, but it won’t work because Lemmy assumes an initial contact via http/1.1 with an http status code of 101 to push to http/2.0. Apache can proxy either but not both. And Lemmy isn’t happy of the initial connection is http/2.0.
I’m also uncomfortable with my lack of knowledge regarding Nginx. I don’t know how to recreate my mod_rewrite rules and I don’t think there’s an equivalent to mod_security.
Worse, I don’t see an easy way to retain docker logs. Yes, I can likely use volumes in a docker-compose.yml to retain them, but it’s far from clear what path that would be.
I know all of these are solveable concerns with some effort, but I suspect few put in that effort.
How do all of you who run containers in a home lab sleep at night knowing all that log data is ephemeral unless you take special effort? How do you sleep knowing the sample configs you are using in containers have little security built in?
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How is it ephemeral? My Docker instance for Lemmy logs forever unless I manually clear the logs. My Caddy reverse proxy logs every request too. Both are stored to disk and I'm free to copy them out at any time. They'll keep increasing in size until I decide to clear them.
They're logged through the Docker engine, not the container. A malicious actor would require a sophisticated container breakout attack to even attempt to clear them. Those attacks are rare and highly publicized.
Alternatively, an attacker could try to find my real instance IP from behind Cloudflare (probably not going to happen), somehow bypass my provider's firewall which only allows SSH from my home IP (my home is more likely to be broken into than that), and then somehow defeat SSH authentication on top of both of those (quantum computers aren't quite there yet).
I'm having trouble seeing the risk you're concerned about.
My concern is less the VM hosting the docker instance getting compromised but that Lemmy has an exploit and the Lemmy instance getting compromised. I’m quite certain that Lemmy is getting a closer look by the bad guys. You’ve had hundreds of instances spun up in a week, most that have done nothing more than follow an online example of how to spin up a Lemmy instance.
And, I was under the impression that the container and thus the logs were cleared when restarting or redeploying docker. If I’m wrong, I’m horribly embarrassed and will point at that “old school” in the title. I’ll also be doing some testing.
No worries! There's always something new to learn.
Docker has different log drivers, and the one used by default in Docker Compose (which is recommended by Lemmy) is called
json-file, which logs to a file on the disk. Thelocaldriver is more commonly used by one-off Docker containers, and that one is ephemeral, although you could also usejson-filethere if you wanted.If Lemmy itself has an exploit, at the absolute maximum, my instance either has its content cleared, or maybe it gets used for spam. I don't see a scenario where anything outside of my container can be touched, containers are pretty secure.
Any attack on Lemmy would also be extremely widespread, and a random person like me likely wouldn't be a target regardless. But if I were, I'd just restore one of my regular backups.
In any case, there is nothing to be done if Lemmy does have a dormant zero day vulnerability - we either use it or we don't. No one is going to set up enterprise grade WAFs to use this hobbyist federation software, and it would likely break federation regardless.
You’ve had hundreds of instances spun up in a week, most that have done nothing more than follow an online example of how to spin up a Lemmy instance.
That's true, but relatively speaking, Docker is pretty secure. The configs they provide aren't bad either. Lemmy is a simple frontend service and a simple set of microservices, pretty much as small of an attack surface as you can get.
And Lemmy is written in Rust - I would be extremely surprised to learn a Rust application has an undetected RCE. But again, even if it did, the damage is contained to Lemmy itself and its backing postgres database. If I wanted to do postmortem forensics, I still have my Docker + access logs, which would include every web request (and thus attack payload) my proxy has ever received.
As @[email protected] said, Docker has different log drivers. one of them is good old Syslog...
Put this in you
/etc/docker/daemon.json{ "log-driver": "syslog", "log-opts": { "syslog-address": "unixgram:///dev/log" }Perfect! Thanks.