Hacker News new | ask | show | jobs
by MalcolmDiggs 4005 days ago
In my experience, if you start hearing: "I don't know what's wrong, it works fine on my localhost!" a lot, then it may be time to think about Docker.

In more general terms: more the complex the environment, the more moving pieces, the more developers on the team, the more servers in production, the more likely there's going be a discrepancy between what Developer-A has running on his machine, and what Developer-B has running on theirs. Docker helps keep everybody on the same page.

For me personally: I'm a dev on a number of projects, and Docker helps me keep my dependencies straight. I no longer have to change things around locally just to work on Project-A, I just get their latest Docker image, and I'm good to go.
2 comments
marcusandre 4005 days ago
This seems pretty fine but it's not a Docker-specific argument. The same arguments fits for a Vagrant-Workflow.
link
msravi 4005 days ago
How is this different from sharing a plain old VM image and doing the same thing? Is there any particular advantage that a Docker image brings?
link
Matt3o12_ 4005 days ago
Docker images use the union file system. That means when a new version of that image is available, you often only pull a few megabytes from the hub because it already has the OS.

A docker container is also way more lightweight. Instead of running a full OS, you I only run one process. So your docker image starts within seconds

link
ccozan 4005 days ago
Is this more like a Solaris zone or a Linux chroot-ed env?
link
nickstinemates 4005 days ago
A lot like Linux chroot, with some additional features, restrictions, and a mechanism to share them easily.
link
16bytes 4005 days ago
For one, speed. Provisioning a VM image takes a lot longer than a container.

Secondly, composition. Can you provision and link the 10 instances that make up your application? Web servers, app servers, proxies, caches, databases, hadoop etc.

I think this second ability is the truly compelling one for me. The features that allow this (swarm and compose for docker, lots of other competing orchestration stuff) are still pretty young, but it would still push me in the direction of containerization over virtualization.

link