This is a pretty good analogy for containers but there's an unfortunate conflation of terms. There's actually a distinction with computing containers between the thing that you ship code around as and the thing that you run code in. The latter is the real container while the prior is called a "container image" or often simply an "image." This gets confusing quick if you apply this analogy since you assume that the thing you ship the code as would naturally be called the container.
WTF is a container?
31–40 of 262 posts
Re: WTF is a container?
#32for the love of god - forget docker, use lxc containers - its simple, secure, goes with its own init, cron, and you dont need to do somersaults to achieve simple tasks. Included with linux kernel. Your own isolated linux system. We use lxc in production for over three years, and we have over 3000 of them. No issues whatsoever.
Do you have any examples of what LXC does better than docker? I'm very new to the whole containerization thing but I've already come across a couple of the issues you've mentioned.
Re: WTF is a container?
#33Docker is the best thing since sliced bread! VM is much more resource and time consuming. # We switched our dev/stage env to containers 2 year ago. # We have made our own standalone app in Docker style. Once again - Easy as pie. if you are a developer you should add Docker + Docker Compose to you working tools.
We moved over to Docker at the development process some time ago and it really speed up our work.
Re: WTF is a container?
#34I 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 gives you the building blocks, but that means you have more pieces to arrange and manage. Take a look at Docker Compose if you haven't already, since the Docker CLI only gets you so far when you're creating apps that consist of multiple containers. I think the best approach for your cert issue is to abstract that into a separate service (nginx is an option, but I'd recommend the Rancher approach below). Yes, t…
> but that means you have more pieces to arrange and manage
wait. aren't these things supposed to give us less pieces to arrange and manage?
> The problems that you're having are pretty easy to fix with some tooling
yes, of course the solution is more tools. what exactly was the problem again?
Re: WTF is a container?
#35I 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 gives you the building blocks, but that means you have more pieces to arrange and manage. Take a look at Docker Compose if you haven't already, since the Docker CLI only gets you so far when you're creating apps that consist of multiple containers. I think the best approach for your cert issue is to abstract that into a separate service (nginx is an option, but I'd recommend the Rancher approach below). Yes, t…
Thanks, I'll have to look into Rancher. I'm already using Docker-compose.
Also good to know about automatic restarts. I don't know how I missed that, I had to read a lot of docs to get where I am.
Still, the amount of tooling that exists and the knowledge needed to pick the right ones for a given situation goes to show that this isn't as simple as packing a shipping container and letting someone ship it...
Re: WTF is a container?
#36I 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…
You might have better luck with container specific reverse-proxy like Traefik[0] - it has builtin Let's Encrypt support with auto-renewal
> I had a huge amount of headaches to get it actually working.
Moving from running one container to running multiple containers is probably one of the most confusing parts of getting started with Docker
There are a large array of orchestration options and tools - each with their own pros and cons: Swarm, Kubernetes, Mesos, Marathon, Mesosphere, Centurion, Rancher, etc.
Docker 1.12 now having built-in orchestration with Swarm should make this easier[1].
[0] https://github.com/containous/traefik
[1] https://blog.docker.com/2016/06/docker-1-12-built-in-orchest...
Re: WTF is a container?
#37Earlier quoted context omitted.
They were called "jails" long before "containers" became a thing on HN. Somehow "jails" didn't stick, so I'd assume it was even more confusing for newcomers.
Jail had no marketing hook. It's a very negative word. I'd guess that's Probably the major reason.
Well that and it wasn't done by a VC backed firm with strong press connections.
Re: WTF is a container?
#38for the love of god - forget docker, use lxc containers - its simple, secure, goes with its own init, cron, and you dont need to do somersaults to achieve simple tasks. Included with linux kernel. Your own isolated linux system. We use lxc in production for over three years, and we have over 3000 of them. No issues whatsoever.
Encouraging to hear. Who do you work for, who has these 3,000 LXC containers in production use? And I'm curious, what orchestration system do you use to manage them? Can you outline your toolset?
We use ansible and bash scripts for orchestration.
Re: WTF is a container?
#39for the love of god - forget docker, use lxc containers - its simple, secure, goes with its own init, cron, and you dont need to do somersaults to achieve simple tasks. Included with linux kernel. Your own isolated linux system. We use lxc in production for over three years, and we have over 3000 of them. No issues whatsoever.
Do you have any examples of what LXC does better than docker? I'm very new to the whole containerization thing but I've already come across a couple of the issues you've mentioned.
Shameless copypaste from well written piece by Flockport:
Docker restricts the container to a single process only. The default docker baseimage OS template is not designed to support multiple applications, processes or services like init, cron, syslog, ssh etc.
As we saw earlier this introduces a certain amount of complexity for day to day usage scenarios. Since current architectures, applications and services are designed to operate in normal multi process OS environments you would need to find a Docker way to do things or use tools that support Docker.
Take a simple application like WordPress. You would need to build 3 containers that consume services from each other. A PHP container, an Nginx container and a MySQL container plus 2 separate containers for persistent data for the Mysql DB and WordPress files. Then configure the WordPress files to be available to both the PHP-FPM and Nginx containers with the right permissions, and to make things more exciting figure out a way to make these talk to each other over the local network, without proper control of networking with randomly assigned IPs by the Docker daemon! And we have not yet figured cron and email that WordPress needs for account management. Phew!
This is a can of worms and a recipe for brittleness. This is a lot of work that you would just not have to even think about with OS containers. This adds an unbelievable amount of complexity and fragility to basic deployment and now with hacks, workarounds and entire layers being developed to manage this complexity. This cannot be the most efficient way to use containers.
Can you build all 3 in one container? You can, but then why not just simply use LXC which is designed for multi processes and is simpler to use. To run multiple processes in Docker you need a shell script or a separate process manager like runit or supervisor. But this is considered an 'anti-pattern' by the Docker ecosystem and the whole architecture of Docker is built around single process containers.
Docker separates container storage from the application, you mount persistent data with bind mounts to the host (data volumes) or bind mounts to containers (data volume containers)
This is one of the most baffling decisions, by bind mounting data to the host you are eliminating one of the biggest features of containers for end users; easy mobility of containers across hosts. Probably as a concession Docker gives you data volumes, which is a bind mount to a normal container and is portable but this is yet another additional layer of complexity, and reflects just how much Docker is driven by the PAAS provider use case of app instances.
Re: WTF is a container?
#40for the love of god - forget docker, use lxc containers - its simple, secure, goes with its own init, cron, and you dont need to do somersaults to achieve simple tasks. Included with linux kernel. Your own isolated linux system. We use lxc in production for over three years, and we have over 3000 of them. No issues whatsoever.
You're right that LXC containers have a similar API compared to Docker, but I think developers often underestimate the benefit of the community around a certain technology. Docker has significantly better documentation, extensions, package management tools, and third-party integrations. Overall, Docker has an incredibly more robust community than LXC or closer competitors like Kubernetes, and those features are just…
The point of the LXC is, you get a full blown standalone linux, rather than a single process - this simplifies everything a lot, meaning you don't have to have that much documentation about it in the first place.