Cybersecurity

Thus, a PPA owner is much less likely to get compromised.

Again, I have yet to see evidence of a Docker repo being compromised.

Repos are almost never compromised. Most issues are from users making things insecure because it's easier that way. As in:

• opening too many ports
• enabling passwordless sudo
• removing SELinux rules instead of just the parts they need

And so on. Docker makes it really easy to throw away the entire VPS and redeploy, which means those bad configs are less likely to persist in production.

Installing things from source in a secure environment is about as safe as you can get, when obtaining the source securely.

Sure, but that's only true from the moment you release.

Source-compiled packages rarely get updated, at least in my experience. However, putting source packages in a Docker container increases those chances because it's really easy to roll back if something goes wrong, and if you upgrade the base, it rebuilds the source with those new libraries, even if statically compiled.

If you're talking about repository packages built from source (I'm not, I'm talking about side-loading packages), that's not really a thing anymore with reproducible builds.

Ist there already a builtin way to update all installed docker containers?

In our CI pipeline, yes, I just run a "rebuild all" script and it's ready for the next deploy to production. Or the script run could be totally automated (I'm currently fighting our devOPs to enable it). We do ":-" pattern, so worse case, we update from "bullseye" to "bookworm" or whatever separately from the version and ship that. Total process is like 20s per repo (edit Dockerfile out docker-compose.yml, make PR, then ship), then whatever time it takes to build and deploy.

But I don't necessarily want to upgrade everything. If I upgrade the OS version, I need to check that each process I use is compatible, so I'm more likely to delay doing it. With Docker, I can update part of my stack and it won't impact anything else. At work, we have dozens of containers, all at various stages of updates (process A is blocked by dependency X, B is blocked by Y, etc), so we're able to get most of them updated independently and let the others lag until we can fix whatever the issues are.

When installing to the host, I'd need to do all of it at once, which means I'm more likely to stay behind on updates.

That's false.

Source? I'm coming from ~15 years of experience, and I can say that servers rarely see updates. Maybe it happens in larger firms, but not in smaller shops. But then, larger firms can also run security audits of docker images and whatnot.

Basically one compromised container giving local execution is enough to pwn your complete host.

Maybe. That depends on if the attacker is able to get out of the sandbox. If it was a vulnerability in a process on the host, there's no sandbox to escape.

So while your Docker containers will probably lag a bit, they come with a second layer of protection. If your host lags a bit, there's probably no second layer of protection.