Adds GOARCH option to build

Signed-off-by: JoshVanL <vleeuwenjoshua@gmail.com>

Author: JoshVanL

Makefile

@@ -3,6 +3,7 @@ BINDIR    ?= $(CURDIR)/bin
 HACK_DIR  ?= hack
 PATH      := $(BINDIR):$(PATH)
 ARTIFACTS ?= artifacts
+ARCH      ?= amd64
 
 SHELL = /bin/bash -o pipefail
 
@@ -99,7 +100,7 @@ build: generate ## build kube-oidc-proxy
 	CGO_ENABLED=0 go build -ldflags '-w $(shell hack/version-ldflags.sh)' -o ./bin/kube-oidc-proxy ./cmd/.
 
 docker_build: generate test build ## build docker image
-	GOOS=linux CGO_ENABLED=0 go build -ldflags '-w $(shell hack/version-ldflags.sh)' -o ./bin/kube-oidc-proxy-linux  ./cmd/.
+	GOARCH=$(ARCH) GOOS=linux CGO_ENABLED=0 go build -ldflags '-w $(shell hack/version-ldflags.sh)' -o ./bin/kube-oidc-proxy-linux  ./cmd/.
 	docker build -t kube-oidc-proxy .
 
 all: test build ## runs tests, build

test/kind/image.go

@@ -128,7 +128,7 @@ func (k *Kind) runCmdWithOut(w io.Writer, command string, args ...string) error
 	cmd.Env = append(cmd.Env,
 		"GO111MODULE=on", "CGO_ENABLED=0", "HOME="+os.Getenv("HOME"),
 		"PATH="+os.Getenv("PATH"),
-		"GOOS=linux")
+		"GOARCH=amd64", "GOOS=linux")
 
 	if err := cmd.Start(); err != nil {
 		return err