Before containers we would script the install process using Ansible. With containers we script the install process using a Dockerfile. If you know how to do one, you know how to do the other. Just don't be lazy and use unofficial images created by people you don't know or trust. Just like you wouldn't pull any random role from ansible-galaxy. Or pull a random guy off the street and ask them to provision your infrastructure for you.
Then all you have to do is just rebuild your images every week and you're set. All we had to do for this was have our Jenkins build pipeline run weekly & have it pass `--pull --no-cache` to `docker build`.
Thanks for mentioning this, will definitely have to give this another go.
Already done: Solaris zones. Available in the SmartOS distribution near you. Combine with OS packaging, imgadm and vmadm commands for maximum impact.
How does provide visibility into every dependency inside an image? Especially when using 3rd-party-maintained images that consist of significant hours of work per image to get the image to work.
(BTW., I built "live CD images" for use in physical and virtual machines since ~2001, using tools such as mklivecd, livecd-tools etc.).
Do they though?
Whenever I write Dockerfiles that depend on external downloads, I always check the hash matches one baked into the Dockerfile itself, and I've always seen others doing the same.
I'm not saying it's a good thing, but that's what I observed.
I really just haven't seen this with the ones I use.
I meant the opposite. The high profile containers generally do the right thing, but containers created by peers rarely do it.
There's no mechanism to make things reproducible you need to implement it yourself, and from my experience most people (not the ones that release something publicly, but ones that work for a companies that use it) don't do it.
Just look at the popular images on Docker hub.
A lot of them involve messy build steps, including downloading binaries or source tarballs without verification.
It's often hard to know which dependencies a Docker image has, and therefore hard to track vulnerabilities and redeploy fixed images.
A lot of docker containers end up either running for a long time, or get rebuilt and redeployed often, but have pinned versions of base images or dependencies which still leaves vulnerabilities in place.
This is compensated a bit by the fact that Docker does provide somewhat decent isolation, and most containers are run in a cloud environment, behind load balancers and with decent security constraints. But there are many pitfalls in the whole process.
Containers provide a lot of advantages, and are certainly where things will continue to go.
But we need to figure out the tooling and ecosystem story to build, verify and update container deployments securely.