[zwischenzug]

Some key points:

- Docker is nothing new - it's a packaging of pre-existing technologies (cgroups, namespaces, AUFS) into a single place

- Docker has traction, ecosystem, community and support from big vendors

- Docker is _very_ fast and lightweight compared to VMs in terms of provisioning, memory usage, cpu usage and disk space

- Docker abstracts applications, not machines, which is good enough for many purposes

Some of these make a big difference in some contexts. I went to a talk where someone argued that Docker was 'just a packaging tool'. A sound argument, but packaging is a big deal!

Another common saw is "I can do this with a VM". Well, yes you can, but try spinning up 100 vms in a minute and see how your MacBook Air performs.

[3pt14159]

What is important to note is that the ideal use case for Docker is not actually speed - it's about quickly responding to increased load. If you need to vary the number of, say, web servers from 5 to 100 over the day, then Docker is good because you can start them up very quickly.

The down side about docker is that it takes longer to set up your docker in the first place, it is harder to keep secure, and it runs slower than a traditionally deployed application, but compared to VM deployed applications the performance is usually better.

[arenaninja]

Docker is indeed fast and lightweight. It's amazing how much CPU power is freed up from not running a full on VM in VirtualBox. That said, I'm wary of running it in production

[yellowapple]

In my experience, the performance gains are much less significant v. a virtual machine running on a proper bare-metal hypervisor (like Xen).

[zwischenzug]

Why? Security?

[arenaninja]

Yep. I don't understand the security implications well enough to guard against them. As much as I like cutting edge tech I prefer to not actually cut myself with it!

[zwischenzug]

PM if you want to talk more.

[hosh]

Yes, packaging is a big deal!