Note: When go-grpc-prometheus was in the main $gopath (even at this
version) and everyone else was where they always were in vendor/ this
didn't build! It gave errors like:
have SendHeader("github.com/purpleidea/mgmt/vendor/google.golang.org/grpc/metadata".MD) error
want SendHeader("google.golang.org/grpc/metadata".MD) error
and I got frustrated. Putting it "next" to the other vendored deps seems
to have fixed this. Where are the golang docs that explain this
phenomenon?
This also requires golang 1.8+ as that is a requirement for etcd. It's
probably a reasonable thing for us too.
Note the older versions of etcd had some bugs with the concurrency
package and other things, so this is a necessary bump.
