Fix armv7 docker builds

Moves the ARCH build argument after the first FROM so it has the proper
value.
(https://docs.docker.com/engine/reference/builder/#understand-how-arg-and-from-interact)

Adds the GOARM=7 option to the armv7 GO build.

Fixes #239

Author: groggemans

Dockerfile

@@ -12,10 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-ARG ARCH=amd64
-
 FROM k8s.gcr.io/build-image/debian-base:buster-v1.6.0
 
+ARG ARCH=amd64
+
 # Copy nfsplugin from build _output directory
 COPY bin/${ARCH}/nfsplugin /nfsplugin
 

Makefile

@@ -100,7 +100,7 @@ nfs:
 
 .PHONY: nfs-armv7
 nfs-armv7:
-	CGO_ENABLED=0 GOOS=linux GOARCH=arm go build -a -ldflags "${LDFLAGS} ${EXT_LDFLAGS}" -mod vendor -o bin/arm/v7/nfsplugin ./cmd/nfsplugin
+	CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=7 go build -a -ldflags "${LDFLAGS} ${EXT_LDFLAGS}" -mod vendor -o bin/arm/v7/nfsplugin ./cmd/nfsplugin
 
 .PHONY: container-build
 container-build: