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

WTF is a container?

techcrunch.com

Post reply on HN
Print view View original

81–90 of 262 posts

Re: WTF is a container?

#81

Post by Gruselbauer »

dancek wrote: post #5

I agree that containers (both for shipping and servers) are a great idea. And because I'm tired of always configuring servers, I decided to give it a try some time ago. I wrapped my IRC client (weechat + glowing-bear) in a Docker container. Oh, not a container though, because I also needed https, which meant I needed either a mechanism to build and update letsencrypt certs in the weird format that weechat expects, or…

I'm doing the same with a couple of containers and my experience is pretty much the opposite. What containers are you using, if I may ask?

I'm using jwilder's nginx rproxy container, the let's encrypt helper container for that plus half a dozen Web apps on a VPS. Among those Weechat, two instances of vanilla nginx, rutorrent, dovecot, mattermost, nextcloud and a test environment for my Python tinkering. Works like a charm. Upon bringing up a new container, I supply the desired subdomain and my letsencrypt user data, the container comes up and uses SSL plus automatically renewed certificates.

My Docker experience so far - in a private, limited, very much not production environment - has been "virtualisation light" all the way.

I think of Docker as a somewhat extended chroot, to wrap my mind around it.

Re: WTF is a container?

#82

Post by vacri »

Philipp__ wrote: post #49
dancek wrote: post #5

I agree that containers (both for shipping and servers) are a great idea. And because I'm tired of always configuring servers, I decided to give it a try some time ago. I wrapped my IRC client (weechat + glowing-bear) in a Docker container. Oh, not a container though, because I also needed https, which meant I needed either a mechanism to build and update letsencrypt certs in the weird format that weechat expects, or…

Docker is just overhyped deal with it. There are some nice ideas, but nothing that we couldn't or haven't seen before. FreeBSD Jails and Solaris Zones exist for more than ten years. Where they addressed many things that Docker didn't.

Can you download a BSD Jail image from an application's website, and have it 'just work'?

Re: WTF is a container?

#83

Post by Philipp__ »

vacri wrote: post #82
Philipp__ wrote: post #49

Earlier quoted context omitted.

Docker is just overhyped deal with it. There are some nice ideas, but nothing that we couldn't or haven't seen before. FreeBSD Jails and Solaris Zones exist for more than ten years. Where they addressed many things that Docker didn't.

Can you download a BSD Jail image from an application's website, and have it 'just work'?

No, but I do not see how it is related to my comment. Read more carefully. I didn't say that Jails and Zones did everything that Docker did, yeah DockerHub is cool and I gave them credits for that.

Re: WTF is a container?

#84

Post by jonatron »

Philipp__ wrote: post #49
dancek wrote: post #5

I agree that containers (both for shipping and servers) are a great idea. And because I'm tired of always configuring servers, I decided to give it a try some time ago. I wrapped my IRC client (weechat + glowing-bear) in a Docker container. Oh, not a container though, because I also needed https, which meant I needed either a mechanism to build and update letsencrypt certs in the weird format that weechat expects, or…

Docker is just overhyped deal with it. There are some nice ideas, but nothing that we couldn't or haven't seen before. FreeBSD Jails and Solaris Zones exist for more than ten years. Where they addressed many things that Docker didn't.

I ran into weird problems with FreeBSD Jails. Like cronjobs running twice, and `ezjail-admin console` not allocating a tty.

Re: WTF is a container?

#85

Post by dragonsh »

dancek wrote: post #5

I agree that containers (both for shipping and servers) are a great idea. And because I'm tired of always configuring servers, I decided to give it a try some time ago. I wrapped my IRC client (weechat + glowing-bear) in a Docker container. Oh, not a container though, because I also needed https, which meant I needed either a mechanism to build and update letsencrypt certs in the weird format that weechat expects, or…

Containers!=docker, I think if you used lxd container, your experience might have been different as they work like virtual machine. I am using lxd in production and it has been a pleasure with live migration, snapshots and good old configuration management using ansible.

Re: WTF is a container?

#86

Post by saji13 »

pjmlp wrote: post #74
dancek wrote: post #5

I agree that containers (both for shipping and servers) are a great idea. And because I'm tired of always configuring servers, I decided to give it a try some time ago. I wrapped my IRC client (weechat + glowing-bear) in a Docker container. Oh, not a container though, because I also needed https, which meant I needed either a mechanism to build and update letsencrypt certs in the weird format that weechat expects, or…

As others say Docker is probably over-hyped technology. However, I do see it as positive, because its hype, regardless if good or not, has created the traction for Go and OCaml on the data center, thus eventually leading to less C code for such use cases. So hype or not, maybe we do get some security improvements on the overall stack.

Out of curiosity, why is less C code a good thing?

Re: WTF is a container?

#87

Post by IshKebab »

ChoHag wrote: post #58
nvarsj wrote: post #45

Earlier quoted context omitted.

Docker is a poorly engineered and over-hyped technology. The concept is great - and in fact, many companies have built great tooling around Linux cgroups. It lets you efficiently binpack applications on a single server - which is why 'containers' were created in the first place. The side benefit of letting you define your OS libraries, and other things, is a nice bonus, and way overblown in my opinion. Docker and its…

The concept is great but it's also not original. It's called "processes". Docker is little more than a mass of complication laid atop fork+exec. That's why nobody can get it right - because we already did.

I totally agree. The real issue is dynamic libraries and how hard it is to compile C/C++ code statically with GCC.

If you could just pass `-static` to gcc and it actually worked like you expect this would never have happened.

Fortunately that seems to be changing somewhat. Go is totally static, and Rust can easily be made totally static using muscl. You can even do totally static C/C++ apps fairly easily with muscl.

Re: WTF is a container?

#88

Post by IshKebab »

Hondor wrote: post #62

I never quite understood containers and this article makes them seem kind of similar to what OSs already do. How is a container different from just installing all the dependencies along with an application? Coming from a Windows background, this is pretty common to avoid DLL hell. Nobody distributes a Windows application that requires the user to go and install some 3rd party library before it'll work. Isolation from…

You are correct. The issue they really fix is that it is extremely difficult to actually distribute all dependencies along with an app on Linux. If you link with glibc they you are screwed.

There are starting to be ways around glibc, like muscl. And Go doesn't even use a C standard library at all - there's no way you can say that Docker is easier than just copying a single statically linked binary around. But I guess Docker came along before those solutions have become really popular, and it is easier to apply to existing apps.

I think the security isolation is a side-benefit that is used to obscure the real reason for docker (distributing apps on Linux sucks).

Re: WTF is a container?

#89

Post by vacri »

Hondor wrote: post #62

I never quite understood containers and this article makes them seem kind of similar to what OSs already do. How is a container different from just installing all the dependencies along with an application? Coming from a Windows background, this is pretty common to avoid DLL hell. Nobody distributes a Windows application that requires the user to go and install some 3rd party library before it'll work. Isolation from…

> Nobody distributes a Windows application that requires the user to go and install some 3rd party library before it'll work.

On Saturday I installed a Steam game on Windows 10, and it forced me to download and install .Net 3.5 before it would launch.

> How is a container different from just installing all the dependencies along with an application?

It's more flexible - for example, you can set up your container so you can ssh into it and do some commandline troubleshooting.

Re: WTF is a container?

#90

Post by madeofpalk »

raesene6 wrote: post #68
Hondor wrote: post #62

I never quite understood containers and this article makes them seem kind of similar to what OSs already do. How is a container different from just installing all the dependencies along with an application? Coming from a Windows background, this is pretty common to avoid DLL hell. Nobody distributes a Windows application that requires the user to go and install some 3rd party library before it'll work. Isolation from…

Containers (and especially multi container orchestration software like docker compose or Kubernetes Pods) let you describe an application that might contain multiple processes (so a really simple example could be a web server with a database backend) in a single file and have that deployed to any system that runs the containerization software. So to that extent its more flexible than a single app. which bundles its d…

See, rather than thinking of them as applications, I've always found it a lot easier to think of them as super lightweight virtual machine images.

Of course technically they're definitely not but IMHO with the isolation and reproducibility aspects of it VMs sounds most fit.

Post reply on HN