The new version of the urfave/cli library is moving to generics, and
it's completely unclear to me why this is an improvement. Their new API
is very complicated to understand, which for me, defeats the purpose of
golang.
In parallel, I needed to do some upcoming cli API refactoring, so this
was a good time to look into new libraries. After a review of the
landscape, I found the alexflint/go-arg library which has a delightfully
elegant API. It does have a few rough edges, but it's otherwise very
usable, and I think it would be straightforward to add features and fix
issues.
Thanks Alex!
It was a bit awkward using `mgmt run lang --lang <input>` so instead, we
now drop the --lang, and read the positional argv for the input.
This also does the same for the --yaml frontend.
This is a giant cleanup of the etcd code. The earlier version was
written when I was less experienced with golang.
This is still not perfect, and does contain some races, but at least
it's a decent base to start from. The automatic elastic clustering
should be considered an experimental feature. If you need a more
battle-tested cluster, then you should manage etcd manually and point
mgmt at your existing cluster.