Fix to report the correct version inside container.

- Used build args to pass the correct version.

Dockerfile

@@ -30,13 +30,14 @@ ADD . /go/src/github.com/kubernetes-incubator/node-feature-discovery
 
 WORKDIR /go/src/github.com/kubernetes-incubator/node-feature-discovery
 
+ARG NFD_VERSION
 RUN git clone --depth 1 https://github.com/01org/intel-cmt-cat.git
 RUN cd intel-cmt-cat/lib; make install
 RUN cd rdt-discovery; make
 RUN go get github.com/Masterminds/glide
 RUN glide install
 RUN go install \
-  -ldflags "-s -w -X main.version=`git describe --tags --dirty --always`" \
+  -ldflags "-s -w -X main.version=$NFD_VERSION" \
   github.com/kubernetes-incubator/node-feature-discovery
 
 ENTRYPOINT ["/go/bin/node-feature-discovery"]

Makefile

@@ -9,6 +9,7 @@ VERSION := $(shell git describe --tags --dirty --always)
 all: docker
 
 # To override QUAY_REGISTRY_USER use the -e option as follows:
-# QUAY_REGISTRY_USER=<my-username> make docker -e
+# QUAY_REGISTRY_USER=<my-username> make docker -e.
 docker:
-	docker build -t $(QUAY_DOMAIN_NAME)/$(QUAY_REGISTRY_USER)/$(DOCKER_IMAGE_NAME):$(VERSION) ./
+	docker build --build-arg NFD_VERSION=$(VERSION) \
+		-t $(QUAY_DOMAIN_NAME)/$(QUAY_REGISTRY_USER)/$(DOCKER_IMAGE_NAME):$(VERSION) ./