Enable setting GOPROXY and GOPRIVATE during build.

Dockerfile

@@ -6,6 +6,8 @@ FROM --platform=${BUILDPLATFORM} ${BUILDER_IMAGE:-golang:1.17.2} as builder
 
 ARG TARGETOS
 ARG TARGETARCH
+ARG GOPROXY
+ARG GOPRIVATE
 
 WORKDIR /workspace
 
@@ -25,6 +27,8 @@ COPY pkg/ pkg/
 RUN CGO_ENABLED=0 \
     GOOS=${TARGETOS} \
     GOARCH=${TARGETARCH} \
+    GOPROXY=${GOPROXY} \
+    GOPRIVATE=${GOPRIVATE} \
     GO111MODULE=on \
     go build -mod=mod -a -o manager main.go
 

Makefile

@@ -21,6 +21,8 @@ BUILD=
 GOCMD = go
 GOFLAGS ?= $(GOFLAGS:)
 LDFLAGS =
+GOPROXY   ?=
+GOPRIVATE ?=
 
 default: build test
 
@@ -39,6 +41,8 @@ build-image:
 		--build-arg GOARCH=$(ARCH) \
 		--build-arg BUILDER_IMAGE=$(BUILDER_IMAGE) \
 		--build-arg BASE_IMAGE=${BASE_IMAGE} \
+		--build-arg GOPROXY=${GOPROXY} \
+		--build-arg GOPRIVATE=${GOPRIVATE} \
 		-t "${REPOSITORY_ARCH}" \
 		--load \
 		-f Dockerfile \