I’ve read that standard containers are optimized for developer productivity and not security, which makes sense.
But then what would be ideal to use for security? Suppose I want to isolate environments from each other for security purposes, to run questionable programs or reduce attack surface. What are some secure solutions?
Something without the performance hit of VMs
It is the application Docker that is not secure. Containers are. In fact Docker runs a daemon as root to wich you communicate from a client. This is what makes it less secure; running under root power. It also has a few shortcomings of privileged containers. This can be easily solved by using podman and SELinux. If you can manage to run Docker rootless, then you are magnitudes higher in security.
Do you think Podman is ready to take over Docker? My understanding is that Podman is Docker without the root requirement.
Yes it is. I’ve been using it for more than a year now. Works reliably. Has pod support aswel.
Great. I don’t know enough to use either but I think I’m going to try lean on podman from the get go. In any case, I know that all podman commands are exactly identical to Docker, such that you can replace, say,
docker composewithpodman composeand move on with ease.With the specific exception of podman compose I completely agree. I haven’t tested it for a while but podman compose has had issues with compose file syntax in my experience. Especially with network configs.
However, I have been using “docker-compose” with podman’s docker compatible socket implementation when necessary, with great success
Related to this: can podman completely replace Docker? I.e., can it pull containers and build containers in addition to running them?
I believe it can but don’t take my word for it
It can pull and build containers fine but last time I tried there were some differences. Mounts were not usable because user uid/gid behave quite differently. Tools like portainer dont work on podman containers. I havent tried out any networking or advanced stuff yet.
But i found that the considerations to write docker files are quite different for podman.
Differences you find could be related to containers being run rootless, or the host system having SELinux enforcesd. Both problems could be intended behavior and can be soled simply by using by adding correct labels to mount points like :z or :Z. This SELinux feature also affects Docker when setup.
Portaiers tries to connect to a docker sock path that is not the same with Podman. While podman is rootless and does not need a daemon, socks and stuff, it has support for them nevertheless. So you can simply adjust Portainer config to work with podman. I havnt tried it yet but I managed to do similar things for other software.
All recent CPUs have native virtualization support, so there’s close to no performance hit on VMs.
That being said, even a VM is subject to exploits and malicious code could break out of the VM down to its hypervisor.
The only secure way of running suspicious programs starts with an air-gaped machine, a cheap hdd/ssd that will go straight under the hammer as soon as testing is complete. And I’d be wondering even after that if maybe the BIOS might have been compromised.
On a lower level of paranoia and/or threat, a VM on an up-to-date hypervisor with a snapshot taken before doing anything questionable should be enough. You’d then only have to fear a zero day exploit of said hypervisor.
Each VM needs a complete OS, though. Even at 100% efficiency, that’s still a whole kernel+userspace just idling around and a bunch of caches, loaded libraries, etc. Docker is much more efficient in that regard.
And LXC even more efficient in that regard.
Docker does load a bunch of stuff that most people don’t need for their project.
I don’t know why LXC is always the red-headed stepchild. It works wonderfully.
