| A lot of the cgroups and namespaces functionality too time to mature and stabilize. User name spaces for instance was only available with 3.8. Cgroups and namespaces still don't play well with each other. Cgroups was initially added by some folks from Google in 2007. A lot of the early work on Linux containers was done by Daniel Lezcano and Serge Hallyn of the LXC project, supported by IBM. It was initially a kernel patch and userland tools. You can still see it on the IBM website. It was merged in 2.6.32. Then around 2012 the LXC project started being supported by Ubuntu and Stephane Graber of Ubuntu continued the work with Serge Hallyn. LXC was of course focused on OS containers and they didn't really market themselves. Around 2013 when LXC was finally becoming usable by end users, Docker who were probably using it in their previous avatar in dotcloud as a PAAS platform, took it as a base, modified the container OS's init to run single apps, removed storage persistence, and built it with aufs layers, and took it to market aggressively. But if you look beyond the PAAS centric use case, OS containers are simpler to use, offer near seamless migration of VM workloads, more flexibility in storage and networking scenarios and are more easily used with the ecosystem of apps and tools with a normal multi-process OS environment. The ability to gain the advantages of containers without needing to re engineer how you deploy applications is an incredible value proposition. LXC is mature, pretty advanced and simpler to use than Docker, but a lot of users and media have got the impression that its 'low level' or difficult to use. The Docker, PAAS and micro services folks are the only ones really messaging and going out there to gain adoption and there is an unfortunate conflation of containers to Docker and monoculture developing. The 'Open Container Standard' is an example. Shouldn't that be 'Open App Container Standard'? App containers are a constrained OS environment and add complexity, and the various Docker specific solutions being developed for everything from networking to storage is evidence of the additional complexity. There is obviously a huge devops PAAS case here that people see value in. And the sheer amount of money and engineering deployed means something good has to come out of it. But containers cannot be just about PAAS. I run Flockport that provides an app store [1] based on OS containers that are as easy to use as Docker hub and extensive documentation [2] on using containers so do give it a look. https://www/flockport.com/store https://www.flockport.com/guides |