Fix version info missing

[daixiang0]

Fix #1208

If GO111MODULE does not turn on, set mod as vendor would make version info miss,

Signed-off-by: Xiang Dai 764524258@qq.com

[daixiang0]

@slim-bean @rfratto @cyriltovena mind hava a look?

[slim-bean]

This overlaps some of the work done in #1095, however that PR looks more complete so I'd like to get that merged first and see if we still need this change.

[daixiang0]

@slim-bean #1095 not fix this:

[root@test loki]# make cmd/loki/loki
CGO_ENABLED=0 go build -ldflags "-extldflags \"-static\" -s -w -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Branch=master -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Version=master-125cfbf -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Revision=125cfbf -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.BuildUser=root@test.localdomain -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.BuildDate=2019-11-27T11:12:14Z" -tags netgo -mod vendor -o cmd/loki/loki ./cmd/loki
[root@test loki]# ./cmd/loki/loki --version
loki, version  (branch: , revision: )
  build user:       
  build date:       
  go version:       go1.13.4
[root@test loki]# GO111MODULE=on make cmd/loki/loki
CGO_ENABLED=0 go build -ldflags "-extldflags \"-static\" -s -w -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Branch=master -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Version=master-125cfbf -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Revision=125cfbf -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.BuildUser=root@test.localdomain -X github.com/grafana/loki/vendor/github.com/prometheus/common/version.BuildDate=2019-11-27T11:13:12Z" -tags netgo -mod vendor -o cmd/loki/loki ./cmd/loki
[root@test loki]# ./cmd/loki/loki --version
loki, version  (branch: , revision: )
  build user:       
  build date:       
  go version:       go1.13.4

[pstibrany]

-X github.com/grafana/loki/vendor/github.com/prometheus/common/version.Branch=master

if you still see this, then you're not using Makefile from #1095. It should look like this:

$ make cmd/loki/loki
CGO_ENABLED=0 go build -ldflags "-extldflags \"-static\" -s -w -X github.com/grafana/loki/pkg/loki.Branch=modvendor -X github.com/grafana/loki/pkg/loki.Version=modvendor-f5bf77d -X github.com/grafana/loki/pkg/loki.Revision=f5bf77da -X github.com/grafana/loki/pkg/loki.BuildUser=peter@Peters-iMac.local -X github.com/grafana/loki/pkg/loki.BuildDate=2019-11-27T11:18:23Z" -tags netgo -mod=vendor -o cmd/loki/loki ./cmd/loki

(it wasn't yet merged)

[daixiang0]

oh my mistake, wait for merge! @pstibrany

[sh0rez]

Closing in favor of #1095.

In case there is still something valuable in here, please open a new PR