Add support for arm64

Signed-off-by: Bin Lu <bin.lu@arm.com>

Makefile

@@ -60,8 +60,8 @@ check-docker:
 docker-binary: BINDIR = ./rootfs
 docker-binary: GOFLAGS += -a -installsuffix cgo
 docker-binary:
-	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 $(GO) build -o $(BINDIR)/helm $(GOFLAGS) -tags '$(TAGS)' -ldflags '$(LDFLAGS)' k8s.io/helm/cmd/helm
+	GOOS=linux GOARCH=$(shell go env GOARCH) CGO_ENABLED=0 $(GO) build -o $(BINDIR)/helm $(GOFLAGS) -tags '$(TAGS)' -ldflags '$(LDFLAGS)' k8s.io/helm/cmd/helm
-	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 $(GO) build -o $(BINDIR)/tiller $(GOFLAGS) -tags '$(TAGS)' -ldflags '$(LDFLAGS)' k8s.io/helm/cmd/tiller
+	GOOS=linux GOARCH=$(shell go env GOARCH) CGO_ENABLED=0 $(GO) build -o $(BINDIR)/tiller $(GOFLAGS) -tags '$(TAGS)' -ldflags '$(LDFLAGS)' k8s.io/helm/cmd/tiller
 
 .PHONY: docker-build
 docker-build: check-docker docker-binary
@@ -72,7 +72,7 @@ docker-build: check-docker docker-binary
 docker-binary-rudder: BINDIR = ./rootfs
 docker-binary-rudder: GOFLAGS += -a -installsuffix cgo
 docker-binary-rudder:
-	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 $(GO) build -o $(BINDIR)/rudder $(GOFLAGS) -tags '$(TAGS)' -ldflags '$(LDFLAGS)' k8s.io/helm/cmd/rudder
+	GOOS=linux GOARCH=$(shell go env GOARCH) CGO_ENABLED=0 $(GO) build -o $(BINDIR)/rudder $(GOFLAGS) -tags '$(TAGS)' -ldflags '$(LDFLAGS)' k8s.io/helm/cmd/rudder
 
 .PHONY: docker-build-experimental
 docker-build-experimental: check-docker docker-binary docker-binary-rudder

rootfs/Dockerfile.rudder

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM alpine:3.3
+FROM alpine:3.7
 
 RUN apk update && apk add ca-certificates && rm -rf /var/cache/apk/*