Dockerfile.dapper: Add proxy handling (#1499)

Dockerfile.dapper

 FROM golang:1.13.8-alpine3.10
 
+ARG http_proxy=$http_proxy
+ARG https_proxy=$https_proxy
+ARG no_proxy=$no_proxy
+ENV http_proxy=$http_proxy
+ENV https_proxy=$https_proxy
+ENV no_proxy=$no_proxy
+
 RUN apk -U --no-cache add bash git gcc musl-dev docker vim less file curl wget ca-certificates jq linux-headers zlib-dev tar zip squashfs-tools npm coreutils \
     python2 openssl-dev libffi-dev libseccomp libseccomp-dev make libuv-static
 

scripts/package-image

@@ -10,5 +10,9 @@ REPO=${REPO:-rancher}
 IMAGE_NAME=${IMAGE_NAME:-k3s}
 
 IMAGE=${REPO}/${IMAGE_NAME}:${TAG}
-docker build -t ${IMAGE} -f package/Dockerfile .
+PROXY_OPTS=
+[ -z "$http_proxy" ] || PROXY_OPTS="$PROXY_OPTS --build-arg http_proxy=$http_proxy"
+[ -z "$https_proxy" ] || PROXY_OPTS="$PROXY_OPTS --build-arg https_proxy=$https_proxy"
+[ -z "$no_proxy" ] || PROXY_OPTS="$PROXY_OPTS --build-arg no_proxy=$no_proxy"
+docker build ${PROXY_OPTS} -t ${IMAGE} -f package/Dockerfile .
 echo Built ${IMAGE}