Convert to Go modules (#1178)

* Convert to Go modules

* Update promu config.
* Convert to Go modules.
* Update vendoring.
* Update Makefile.common.
* Update circleci config.
* Use Prometheus release tar for promtool.
* Fixup unpack

* Use temp dir for unpacking tools.
* Use BSD compatible tar command.
* OpenBSD mkdir doesn't support `-v`.

Signed-off-by: Ben Kochie <superq@gmail.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/Makefile b/Makefile
index 459c762..2565f56 100644
--- a/Makefile
+++ b/Makefile
@@ -17,7 +17,9 @@ GO     ?= GO15VENDOREXPERIMENT=1 go
 GOARCH := $(shell $(GO) env GOARCH)
 GOHOSTARCH := $(shell $(GO) env GOHOSTARCH)
 
-PROMTOOL    ?= $(FIRST_GOPATH)/bin/promtool
+PROMTOOL_VERSION ?= 2.5.0
+PROMTOOL_URL     ?= https://github.com/prometheus/prometheus/releases/download/v$(PROMTOOL_VERSION)/prometheus-$(PROMTOOL_VERSION).$(GO_BUILD_PLATFORM).tar.gz
+PROMTOOL         ?= $(FIRST_GOPATH)/bin/promtool
 
 DOCKER_IMAGE_NAME       ?= node-exporter
 MACH                    ?= $(shell uname -m)
@@ -139,6 +141,14 @@ test-docker:
         @echo ">> testing docker image"
         ./test_image.sh "$(DOCKER_REPO)/$(DOCKER_IMAGE_NAME):$(DOCKER_IMAGE_TAG)" 9100
 
-.PHONY: promtool $(FIRST_GOPATH)/bin/promtool
-$(FIRST_GOPATH)/bin/promtool promtool:
-        @GOOS= GOARCH= $(GO) get -u github.com/prometheus/prometheus/cmd/promtool
+.PHONY: promtool
+promtool: $(PROMTOOL)
+
+.PHONY: $(PROMTOOL)
+$(PROMTOOL):
+        $(eval PROMTOOL_TMP := $(shell mktemp -d))
+        curl -s -L $(PROMTOOL_URL) | tar -xvzf - -C $(PROMTOOL_TMP)
+        mkdir -p $(FIRST_GOPATH)/bin
+        cp $(PROMTOOL_TMP)/prometheus-$(PROMTOOL_VERSION).$(GO_BUILD_PLATFORM)/promtool $(FIRST_GOPATH)/bin/promtool
+        rm -r $(PROMTOOL_TMP)
+