Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ask HN: Is it just me or why does Docker suck so much?

news.ycombinator.com

Post reply on HN
Print view View original

61–70 of 85 posts

Re: Ask HN: Is it just me or why does Docker suck so much?

#61

Post by vidarh »

corford wrote: post #10

I've been waiting for the hype to die down a bit and for the project to stabilise before properly playing with it but, from the outside looking in, I must admit I struggle to see how it's gaining as much attention as it is. I can see the advantage for dev boxes where a developer might want to setup a load of containers on their machine to emulate a staging or production environment. But I don't really understand why…

Doing the kvm, plus ansible/puppet/chef approach has the overhead of making testing harder.

I have Docker containers that I rebuild on every test/dev run on some applications, because it is so fast. It means I know the Dockerfile is 100% up to date with my dependencies etc. By the time I'm done testing the application, I'm done testing the container, and it's ready to deploy.

If you need the added security of KVM or similar to isolate your app components, nothing stops you from isolating your Docker containers in a very minimal KVM - even just one container per VM if you prefer, and still get the containerization benefits (which to me is more about having "portable", deployable known fixed units with a repeatable build process than about how it is virtualised; the virtualisation/isolation is a bonus - we could have used Docker without it, by, as mentioned, just running one container per VM).

Re: Ask HN: Is it just me or why does Docker suck so much?

#62

Post by corford »

vidarh wrote: post #61
corford wrote: post #10

I've been waiting for the hype to die down a bit and for the project to stabilise before properly playing with it but, from the outside looking in, I must admit I struggle to see how it's gaining as much attention as it is. I can see the advantage for dev boxes where a developer might want to setup a load of containers on their machine to emulate a staging or production environment. But I don't really understand why…

Doing the kvm, plus ansible/puppet/chef approach has the overhead of making testing harder. I have Docker containers that I rebuild on every test/dev run on some applications, because it is so fast. It means I know the Dockerfile is 100% up to date with my dependencies etc. By the time I'm done testing the application, I'm done testing the container, and it's ready to deploy. If you need the added security of KVM or…

I like the single container on top of a very bare vm approach. That seems like the best of both worlds and (thanks to everyone's replies) I'm beginning to better understand the advantages to testing and deployment docker brings.

Looks like it's time to get my hands dirty and experience first hand what all the fuss is about.

Re: Ask HN: Is it just me or why does Docker suck so much?

#63

Post by ninkendo »

antocv wrote: post #50
lgbr wrote: post #13

Setting up a private repository is a PITA? It's one command: docker run -p 5000:5000 registry Want to back it with S3 or another storage provider? It's still one command: docker run -e SETTINGS_FLAVOR=s3 -e AWS_BUCKET=acme-docker -e STORAGE_PATH=/registry -e AWS_KEY=AKIAHSHB43HS3J92MXZ -e AWS_SECRET=xdDowwlK7TJajV1Y7EoOZrmuPEJlHYcNP2k4j49T -e SEARCH_BACKEND=sqlalchemy -p 5000:5000 registry What's so pain in the ass a…

Yes I have ran that command, I have docker registry running, then I wanted to clean that port and so I put nginx infront and let it proxypass... and have a onename alias for the host that serves the registry so its used by all the machines. But then you see the hostname is confused for username by docker. Argh crap so it cant be clean, at least has to have fqdn. Or port number. Its stuff like this man. Documentation…

+1.

The private registry story is horrible in docker. You have to tag your image with your registry's FQDN, which is an absolutely braindead idea. It's nice to default to docker.io in the absence of options, but I should really be able to do "docker pull --registry myregistry.local ubuntu:latest" and have it work. Instead I have to do "docker pull myregistry.local/ubuntu", which pulls the image and tags it as "myregistry.local/ubuntu". Great, now my registry FQDN is in my image tag. For any decent automation now you have to re-tag it without the "myregistry.local" so you don't depend on your registry FQDN everywhere. But then you better remember to re-tag it with your registry before you push!

In our case we wrote an HDFS driver for the registry so we could store images everywhere, and a service discovery layer to discover registry endpoints (using a load balancer just plain didn't work.) It's an unholy nightmare (but at least we've automated it) to continually re-tag images to go to the endpoint you want.

Re: Ask HN: Is it just me or why does Docker suck so much?

#65

Post by antocv »

ninkendo wrote: post #60

After having used docker for "real" things for the past 8 months or so, I definitely agree with you that it kinda sucks. Docker's strengths come from the workflow you get to use when you use it... "Run /bin/bash in ubuntu" and it just works. For developers that's great. For a backend that does the heavy lifting for you when you're developing a lot of operations automation (like a PaaS), it starts to break down. Just…

I ran into dm issues too, something with grsecurity stopping a bruteforce.

Oh and that ADD this /that will chown 0:0 that. Come on.

Re: Ask HN: Is it just me or why does Docker suck so much?

#66

Post by antocv »

vidarh wrote: post #58
tethra wrote: post #20

Libvirt has support for lxc these days, if memory serves. I'd recommend it - docker just seems heavily marketed. What you're mentioning with hosts/resolv etc is a problem that has been "solved" with tools like etcd and zookeeper as someone else mentioned. I tried docker with a couple of things, and found that it is an environment that (at the time I experienced it, maybe six months ago) was so unhelpful as to appear…

libvirt seems horribly over-engineered to me. I can't stand it. One of the great appeals of Docker to me is the combination of simplicity, and the index/registry. As someone managing hundreds of vm's, and who's being doing Linux sys-admin stuff for 20 years, Docker is the best thing that's happened for a very long time.

We can make it better.

SystemDs containers just need a registry of them tarballed.

Or lxc expanded with a registry/easy to copy root fs.

Re: Ask HN: Is it just me or why does Docker suck so much?

#68

Post by antocv »

vsipuli wrote: post #52

You might want to try systemd-nspawn ( http://www.freedesktop.org/software/systemd/man/systemd-nspa... ). It is much more bare bones than Docker, but in some use cases that might actually be an advantage.

I like systemdnspawn much more than docker. Thanks.

But ubuntu is still anti systemd, garh.

Re: Ask HN: Is it just me or why does Docker suck so much?

#70

Post by GhotiFish »

antocv wrote: post #56
dz0ny wrote: post #3

Q: Why do you want to change /etc/hosts and /etc/resolv.conf (besides hacking DNS for testing purposes)?

Because its used by the applications Id like to contain fully, you know, for all the purposes containers are supposed to be awesome? In this scenario I dont control the dns server and the app reeally likes aliases instead of IPs.

you know. On the project I'm working on, I thought about using the hosts file as a method of configuring the behaviour of a server. "mycomp-eventserver xxx.xxx.xxx.xxx"

In the end, we just created configuration files for it, as more often then not, there are other factors that need to be included.

That said, maybe these requirements are being set by applications that are not yours to mess around with.

In which case, may god have mercy on your soul.

Post reply on HN