[lemieux]

So, basicaly, you're saying that you don't want to mess with that setup and use existing stuff... which you could achieve with everything as long as someone else do the setup for you. I don't see where Docker is better for a developper in this case... providing a vagrant box is exactly the same.

[jfoutz]

Startup time for a docker container is way way faster than a VM. Also, you could run the exact binary state of production, which is helpful if you run into "works on my machine" types of problems.

[lemieux]

Agreed, but my point was that Docker doesn't reduce dev setup time. Give a good vagrant config file to a dev and tell him to do vagrant up and you have the same result as what you're saying. You can replicate production state with vagrant too (and bash scripts if we stretch this) and avoid "works on my machine" problems.

I'm not saying that vagrant > docker. The way I see it, docker is great if your infrastructure is using it all the way. If your prod setup if not dockerized, using docker in dev seems to me counterproductive than spinning up a VM and provisionning it with ansible or puppet to achieve production replication. As @netcraft said, I don't see why I should "change my server architecture" to use docker in dev.

[St-Clock]

I have yet to see real, complex, and distributed applications that share the exact same config in dev and production. I know that having the same versions of system libs in dev and prod can be a problem in some context and docker can help with that, but it's not the only solution and does not take care of the whole landscape (e.g., npm packages.json, pip requirements.txt, etc.).

I totally agree that startup time of a container is far less than a VM, but I don't see how docker "removes all the trouble of running applications that you need for your development: databases, application servers, queues"

You still need to install, configure these services, make sure that the containers can talk to each other in a reliable and secure way, etc.

[saryant]

At the company I work for, we went through all the trouble of getting our distributed backend application running Vagrant using Chef so that we could have identical local, dev and production environments.

In the end, it's just so slow that nobody uses it locally. Even on a beefy Macbook Pro, spinning up the six VMs it needs takes nearly 20 minutes.

We're looking at moving towards docker, both for local use and production, and so far I'm excited by what I've seen but multi-host use still needs work. I'm evaluating CoreOS at the moment and I'm hopeful about it.