vendor: use glide

[gyuho]

For #5658.

[gyuho]

/cc @xiang90 @heyitsanthony What do you think?

glide + glide vc seems working well.

# converting Godeps to glide
cd $GOPATH/src/github.com/coreos/etcd/
mv cmd/Godeps .
rm -rf cmd/vendor
mv cmd/ ..

glide init
cat glide.yaml

glide update --strip-vendor --strip-vcs --update-vendored
glide vc --only-code --no-tests

mv ../cmd .
mv glide.* ./cmd
mv vendor/ ./cmd
git status ./cmd


# update gRPC dependency
vim $GOPATH/src/github.com/coreos/etcd/cmd/glide.yaml
# change version to:
# e78224b060cf3215247b7be455f80ea22e469b66

cd $GOPATH/src/github.com/coreos/etcd/
rm -rf Godeps vendor
mv cmd/glide.lock glide.lock
mv cmd/glide.yaml glide.yaml
mv cmd/vendor vendor

glide update --strip-vendor --strip-vcs --update-vendored google.golang.org/grpc
glide vc --only-code --no-tests

mv glide* ./cmd
mv vendor ./cmd
cat cmd/glide.yaml
git status ./cmd


# add a dependency
glide get

[gyuho]

Deletion is large because it removes READMEs and test files. And test will fail because I tested updating gRPC dependency and there was another breaking change. This is a proof of concept.

[heyitsanthony]

does cd cmd/ && glide update work or does glide still have to shuffle directories like godep?

[gyuho]

Yeah it was self-vendoring the etcd... Maybe I was doing wrong.

[gyuho]

glide has an issue with symbolic links... Masterminds/glide#253

We can experiment again once it gets fixed.