How to maintain a local repository of docker images in case they go offline?
How to maintain a local repository of docker images in case they go offline?
Thanks for all the great replies!
Retag and push to a local registry. Lots of options out there for setting one up.
Honestly, you already have the image locally if you've pulled it. You don't really need to run a registry unless you're dead set on it. You can also flatten and export containers for backup if you really want.
Two good points here OP. Type
docker image lsto see all the images you currently have locally - you'll possibly be surprised how many. All the ones tagged<none>are old versions.If you're already using github, it includes an package repository you could push retagged images to, or for more self-hosty, a local instance of Forgejo would be a good option.
I'd also like to add that you can save an image to a local file using
docker image saveand load them back usingdocker image load. So, along with the options mentioned above, you have plenty of options to backup images for offline use.
Honestly, you already have the image locally if you've pulled it.
I guess not everyone treats their PC as an ephemeral storage, huh? I don't trust anything that's available only locally to survive.
Well the question is about a container disappearing from a public registry, in which case nothing would happen if it's already pulled locally. Figuring where to go from there is the other half of that problem.
Then backup whatever you set your docker local storage to?
The vast majority of selfhosters probably don't but if you want its called a private repository
Just use a sonatype nexus 3 image and proxy docker hub, etc. Then you pull images through it.
We run this at work so we have forever copies of image tags and to reduce dockerhub rate limit issues. Works well even for a large dev team.
Sorry for the link dump - I just glanced over the content and it seems like this might help you:
https://www.warpbuild.com/blog/docker-mirror-setup
https://medium.com/@shaikrish27/deploying-a-docker-registry-mirror-as-a-container-59565ff92c48
https://blog.alexellis.io/how-to-configure-multiple-docker-registry-mirrors/
For most of you suggesting hosting a repository - yes but,
Host forgejo. Just host the git mirror. It comes with a package repo out of the box. Then you have the source code and the docker images
An alternative method is to run an actions workflow that syncs from upstream images directly, like what Forgejo actually do.
oh freaking awesome, this looks amazing! Thank you so much for this!
Host forgejo.
Or Gitea if you want to run the upstream.
I don't know if this will help you, but I wrote a tutorial on how to setup a local registry on the LAN on a Fedora Server or RHEL-compatible server. https://techne.hyperreal.coffee/tutorials/setup-a-lan-container-registry-with-podman-and-self-signed-certs/
But anyway, it's unlikely docker.io or quay.io or ghcr.io will go completely offline. If anything they might experience a DDoS, in which case I imagine they have competent devops employees who would ensure they become functional again within a matter of hours.
Very interesting thanks!
I mean you have the current image cached on the local server when you use it.
At my job, we run goharbor.io and use its Replications feature to do just that.
Isn’t a Docker registry just HTTP? Would a caching proxy be too hard to use for this?