Ask HN: Why use Docker and what are the business cases for using it? • Hacker News Board

Re: Ask HN: Why use Docker and what are the business cases for using it?

#131

Post by stevelandiss » Wed, Jul 01, 2015, 5:32 AM UTC

takeda wrote: post #23

osipov wrote: post #3

There are many ways of using Docker and obviously different companies could come up with their own business cases for adopting the technology. So let me focus on one scenario and we can talk about whether it makes sense for your environment. Software engineering is often difficult because programmers have to deal with inconsistent environments for development and for production execution of their products. Due to mis…

Great, but what are the benefits of running Docker in AWS? You are still running VMs and you are being charged for running them. With Docker you are simply putting yet another layer of complexity, because now you have to run more beefier VMs, you now have problem with network communication between containers running on different hosts. So you will most likely need to use overlay network. You also decrease resiliency,…

@takeda, how do you create 3 different containers in Docker for dev/test/prod? What parameters are you changing in the three stages?

Re: Ask HN: Why use Docker and what are the business cases for using it?

#132

Post by thraxil » Wed, Jul 01, 2015, 10:23 AM UTC

mrbig4545 wrote: post #72

I never figured it out, we could do everything we need in production with LXC, puppet, carton and perlbrew. Combined with a vagrant box for dev, we have no issues. Although I do use docker to run deluge in a container with openvpn on my home pc, but only because someone else had gone to the trouble of writing the dockerfile and getting it to work. It seems to break a lot though, when I have time I'm going to get rid…

> I never figured it out, we could do everything we need in production with LXC, puppet, carton and perlbrew. Combined with a vagrant box for dev, we have no issues.

Would you feel differently if you hadn't already ramped up on all those technologies?

What I mean is that since docker sort of overlaps with much of what people are doing with configuration management, containers, build/packaging systems, and virtualization, it has the potential to reduce the complexity of the stack. If someone's starting fresh, they can potentially avoid having to learn to use and deploy some or all of those different components and just go with docker.

Re: Ask HN: Why use Docker and what are the business cases for using it?

#133

Post by bampolampy » Wed, Jul 01, 2015, 1:12 PM UTC

atsheehan wrote: post #87

lastofus wrote: post #64

Does Docker provide anything useful to someone who develops on OS X and deploys to Linux VMs (Digital Ocean, Linode, AWS)? Current setup is something like: - Develop locally (OS X) - Test deploy to local Vagrant Linux VM (provisioned by Ansible) - Deploy to staging/live Linux VM w/ Ansible (or Fabric if I'm being lazy) I've been following the Docker hype for some time now, but ever time I look into it, I couldn't fin…

An alternative to Docker is Packer ( https://packer.io/ ). It will create and register an AMI for EC2 so you don't have to run any configuration scripts once it is deployed. It's made by the same company that makes Vagrant and uses a similar setup. If you run Ansible to provision the Vagrant VM, I believe you can use the same script to provision the Packer image.

I would not call this an alternative. I think an alternative development workflow involves using packer as well as a number of other top level tools (vagrant for example) and using a number of other languages and DSLs. What you end up with is a VM image, not a container image, so you miss out on some of the container-vm abstractions that make docker and other container technologies so appealing.

Re: Ask HN: Why use Docker and what are the business cases for using it?

#134

Post by collyw » Wed, Jul 01, 2015, 1:55 PM UTC

log_n wrote: post #98

mugsie wrote: post #81

Earlier quoted context omitted.

or, you know, publish the formula, so readers can reproduce in whatever language / system they want. Reproducibility is a big push.... but not like you are suggesting. Shipping a dockerfile is the equivalent of saying "This works, if you use this flask, this pipette, this GCMS and this piece of litmus paper" Docker is not the only solution to problems. It solves some, but you can't tack it on to everything.

Why not both? I am not in academia but I was under the impression that some academics might be publishing 'questionable' results that cannot be reproduced at all in order get their paper count up for tenure review. Not to mention puff-pieces from industry that basically serve as PR in peer reviewed journals without furthering their discipline. So shipping working code (even if it comes with a required pipette) might…

If the code is crap, and only works on one particular data set, then putting it in a docker container ain't going to help.

Re: Ask HN: Why use Docker and what are the business cases for using it?

#135

Post by nnain » Wed, Jul 01, 2015, 2:25 PM UTC

osipov wrote: post #35

takeda wrote: post #23

Earlier quoted context omitted.

Great, but what are the benefits of running Docker in AWS? You are still running VMs and you are being charged for running them. With Docker you are simply putting yet another layer of complexity, because now you have to run more beefier VMs, you now have problem with network communication between containers running on different hosts. So you will most likely need to use overlay network. You also decrease resiliency,…

>what are the benefits of running Docker in AWS? I don't see benefits to running Docker in AWS. In my opinion, AWS implemented its Docker-based Container Service very poorly. I advise my customers against using AWS when want to use Docker. There are many bare metal as a service providers out in the marketplace. >the argument about running the same container in dev/test/prod Is this issue really caused by Docker becau…

I installed the Amazon Linux Installation Image (AMI) with docker and Python 3.4 for a recent project. I know ElasticBeanstalk fairly well, but configuring this was a big headache. WASTED LOT OF TIME.

Instead of making life easy, it just added unnecessary burden of learning Docker for the future project members. Documentation is poor, had to hunt for hours for solutions to simple queries.

On AWS, I would suggest you stick with the basic Linux flavour that you know. Use their Docker build only IF you know docker very well.

Re: Ask HN: Why use Docker and what are the business cases for using it?

#136

Post by njharman » Wed, Jul 01, 2015, 9:27 PM UTC

cheald wrote: post #86

njharman wrote: post #53

Earlier quoted context omitted.

Maybe safe-of-the-art. It is stable (and old) which is the way many people like their servers. But, it certainly isn't the latest and greatest.

The entire point of RHEL/CentOS is that it isn't bleeding edge; it will certainly be modern though. I think it's rather unfair to call it "old" though; the latest release was in March.

Fair enough. But the mentality that picks stable over up-to-date tends to never upgrade. I'm stuck supporting rhel5.5, our "new" systems are 6.5

Re: Ask HN: Why use Docker and what are the business cases for using it?

#137

Post by viktorbenei » Thu, Jul 02, 2015, 6:20 AM UTC

Rezo wrote: post #93

I'd be interested to know if and how people are integrating Docker into their edit-compile-test development cycle? For me personally, the time it takes from performing an edit to seeing your change "live" on a developer's machine is extremely important. To this end we've spent some effort in making our own services and dependencies run natively on both OS X and Linux to minimize the turnaround time (currently at arou…

We do a really simple trick. We have one Dockerfile, which we use for dev and for production, every configuration difference is handled through environment variables (which is easy to manage with docker-compose, Ansible, etc.), so you can run the same image everywhere and change the environment configuration to switch between dev/test/prod.

So to solve the live reload problem we do only one thing in development which we don't do anywhere else: the Dockerfile copies all the current source files into the image, but we run the container with a mounted volume of the source code - which in dev mappes exactly the same way the Dockerfile defines the src copy.

This way when you create the image and start the dev container it won't change anything, but as the src is mounted on top of the included src in the image the regular (Rails) auto reload works perfectly.

For test and prod we just simply don't do any volume mounting at all, and use the baked in src directly.

Easy and fast everywhere, all you have to control is how and when the images are created (ex: we do a full clean checkout in a new directory before building a test image, to ensure it only contains committed code. EDIT: by test I mean for local testing, while you're working on revisions, a CI server does the automatic testing).