Ecosystem - more and more people every day are integrating with their tools, building business around Docker, or extending support of existing business to Docker.
That's my current light at the end of the tunnel, but for now none of them seem mature enough to put my customers on. And it seems like there's a new one every week!
I imagine it'll be easy-ish to migrate between Docker-based PaaS's, though; just upload the container and change the provider-specific config, right? So that's a little reassuring.
Docker just keeps growing and growing. The amount of new businesses springing up to take advtange, along with some pretty heavy hitters looking to adopt, Docker has a fighting chance to become a standard from which everyone benefits.
I'll be presenting this at the Docker Meetup San Mateo hosted by the awesome folks at Edmodo tomorrow night! The event is full, but we will be streaming live!
Docker is a way of making config management easy. Here there really is less stuff. You build a binary with your whole application and all its dependencies that actually self hosts. And is smaller than Docker's init process.
And a VM is better isolated than a Linux container.
EDIT: the restrictions are not necessarily permanent either. Its only a first early release...
Yes, tiny resource overhead while still providing near-complete isolation is a big benefit. The current memory overhead from using file system drivers and TCP/IP networking is around 8MB, and I'm sure there's a bunch of fat in there that could be trimmed off.
It's going to be interesting to see where the exact set of supported application images converges as use cases arise. For example, I'm pretty sure fork() will never be supported -- would it fork the VM? -- but some of the other things are up for discussion.
