A nice selling point for me is the registry. If you have a public image, it's totally free. If it's private, you can pay to use it privately in a team. Of course, you can mount your own (it's a docker image, after all), or you can use Google or Amazon to host it, but it is much easier to pay them to host, and you don't need to bother with storage, backups, or authentication. Setting up team permissions is as easy as sending an invitation from the panel.

Just want to chime in and say running your own registry is actually really easy. It's literally a simple compose file and a bunch of env vars to configure.

It's has letsencrypt built in along with a few options for file storage, including AWS/gcloud.

Getting up and running with your own registry shouldn't really take longer than half an hour. The config docs for the registry image are really helpful with this too.

Sure it's easy...

But for a company it's almost always cheaper to pay for the service. That way you don't have to deal with maintenance, setting up redundancy, mirroring, etc.

That said, aws, google and quay are all competitors in this space.

It's pretty easy to just pay, I'll give you that.

For an example of just how good their image is:

I set my companies up almost a year ago, had to deal with it about once.

The docs cover a HA setup (if you really need it - most won't), data backups aren't really needed if you're using a storage backing, and I just use local file system - absolute worst case I have to wait half an hour to rebuild and push everything.

The downside risk of running your own is very low. The upside is a few bucks and you have your own private registry local to your network.

Just as a small note, data backup isn't just for hardware or service failure, it's also for ooops I just deleted my bucket. Yes you can rebuild, but that in my case would take quite a few days and money in compute. That having been said hosted services are actually worse in protecting your self from user error...

The (public) registry kind of terrifies me. Images of questionable maintenance based on images of questionable maintenance.

There are a lot of heavily used images out there with a bus factor of 1.

Where I work we've (relatively) recently migrated to using GitLab EE which comes with its own container registry[1]. I have no idea how much work it is behind the scenes from my perspective it has been flawless and much more convenient.

[1] https://docs.gitlab.com/ce/user/project/container_registry.h...

We've been using it where I work for a few months and have recently moved to Artifactory. Mainly because GitLab's registry makes it very very painful to remove old images, (you have to remove them from the UI one by one), especially when the number of registries and images grows.

We know that this is a real problem for many users. We plan to resolve it as soon as possible. For now you can use our custom tool that removes old revisions, see https://gitlab.com/gitlab-org/docker-distribution-pruner.

We also have a few issues about this, see https://gitlab.com/gitlab-org/gitlab-ce/issues/25322 and https://gitlab.com/gitlab-org/gitlab-ce/issues/20247.

I hope it helps!

It is available in Gitlab CE too - we don't use it yet as we already have one in-house, but we might migrate in future.

Hmm, GKE's Container Registry also takes care of storage, backups, and authentication. Presumably Quay and Amazon's Container Registry do as well. What makes Docker, Inc.'s registry special?

Dockers registry is really slow. I’ve had many failures where images never finish loading.

VMWare has a really nice free registry, which is s3cure by default and appears to work well.

https://github.com/vmware/harbor

Neither they have regional POPs so anywhere apart from North America the registry is unusable.

Chiming in from Australia. Even considering the fact we have horrific internet anyway, the lack of Australian registry mirrors means that a Docker pull can take ~5 minutes for something like ubuntu:16.04. Docker pushes of ~100MB can take hours. That's just not acceptable.

I also contribute to Docker and other container technologies, and I cannot express in words how horrifically long the Dockerfile-based build and integration testing process takes. It takes about an hour in America, and more than double that in Australia.

I think version control is a good analogy (Subversion and Git). It enables whole classes of products and services to be built on top of it, but that only happens because the basic tool is unambigiously free and can be used everywhere. Trying to monetize the basic thing just damages what makes it valuable.

I feel like docker is core to more businesses than compressing/decompressing files. A lot of business package things in docker containers and are probably more likely to donate based on that. Compressing/decompression feels more like a low-level utility and users are probably unaware of whose code they're running at all.

If the creater of "ls" or "cd" asked for donations, would you even realize? If docker asked for donations, would you realize?

> I feel like docker is core to more businesses than compressing/decompressing files.

All Docker images are glorified tar layers that are compressed with gzip. By definition, all users of Docker are users of gzip and tar. I understand what your point is (it's not as visible) but I don't agree with saying it's "core to more businesses".

Also, if someone is using Kubernetes they soon might not be aware (or even care) whether they're using Docker thanks to the CRI.

> All Docker images are glorified tar layers that are compressed with gzip. By definition, all users of Docker are users of gzip and tar. I understand what your point is (it's not as visible) but I don't agree with saying it's "core to more businesses".

Definitely. I was a little unclear, I meant core as in visibility, which you pointed out.

Also about Kubernetes, I can't comment on that because I've heard used it (but I've heard of it). I think it' s possible that there are a lot of businesses out there (such as the one I work for) that use docker but not Kubernetes.

The more visible an open-source project is, the more likely people are to donate to it. I could definitely see companies supporting docker in the same way that they support the Linux foundation or various Linux distros.

I feel like water and air are core to many lives. Does that make them valuable?

Things are only valuable if they're scarce and in demand.

You can apply this to open source in general, and the main reason why after the lawsuit was settled, the BSDs never became as successful as GNU/Linux.

I old enough to remember PKZIP, ARJ and many other tools.

In all these years, there was only one employer that ever bothered to contribute anything back from what they got for free.

Really sad history about Katz.