Which is probably why people were concerned about Docker's expansion into the clustering and orchestration markets, even if from a business perspective those are their only real holdouts to avoid commodification. The base Docker is easy to replace if the project goes out of hand, the services around it are trickier.
There are several tech streams converging there. A bigger chunk is the space that Mesos and Kubernetes occupy.
And to be fair, I suspect the Docker folks were thinking less about clustering and orchestration so much as: (1) clustering and orchestration still sucks; (2) people want as good of an experience using docker as they do when spanning across multiple nodes; (3) let's make clustering and orchestration less sucky and use the 'Docker Way'[1]
[1] 'Docker Way' is a pointer to the fuzzy, difficult-to-verbalize thing that Docker enables, namely in packaging.
I don't see that changing until we get proper single-system imaging, location transparency, process and IPC migration, process checkpointing and RPC-based servers for representing network and local resources as objects (be they file-based or other) in our mainstream systems.
These things only really caught on in the HPC and scientific computing spaces, where you've had distributed task managers and workload balancers like HTCondor and MOSIX for decades. They've also been research interests in systems like Amoeba and Sprite, but sans that, not much.
The likes of Mesos, the Mesosphere ecosystem with Marathon and Chronos, and Docker Swarm bring only the primitive parts of the whole picture. Some other stuff they can half-ass by (ab)using file system features like subvolumes, but overall I don't see them improving on all the suck.
I ran an OpenMOSIX cluster as a hobby. The alternative was Beowulf (the meme of the day was "Imagine a Beowulf cluster of these things").
It seems the mainstream server industry has moved to more isolation rather than more interconnectedness, which is probably better for most public-facing systems.
Isolation is orthogonal to what I listed. MOSIX has decent sandboxing. I don't know about Linux-PMI or OpenMOSIX, though. They died off years ago anyway.
