Docker allows software and dependencies to be bundled together in ‘containers’. This is a whole level up from a script that installs the libraries for a piece of software to run. A container holds the full environment in its own file system. This means anything you can install/setup on a server can be bundled in the container. The big advantage here is that we then have a portable unit which can be run consistently from machine to machine. Think of Docker as lighter-weight than a VM (e.g. Docker containers don’t have their own kernels, where as a VM would), but giving a similar level of separation, structure and consistency.
~/.ssh/authorized_keys is more than just a file listing valid public keys which can be used for server access. Each key can be preceded by a list of options:
My home internet connection is provided by TalkTalk. I have their medium fibre package. If I had to rate the service out of 10, I’d give it 5 (and even then only just). The consistency isn’t great, the DNS is flakey and TalkTalk keep getting hacked (see here, here and here) meaning I deal with an increasing number of spam calls. Good points are that the service is relatively cheap, and works fine most of the time.
Seen this error before from MySQL?
‘Post formats’ is a neat WordPress feature that lets authors mark posts as a particular type and then allow the theme to style them accordingly. For example a user/blogger might find themselves just posting a picture with a caption and no other content. Such a post would likely make more sense if styled differently.