Bug 1858: Adding APT proxy

Adds apt proxy to build scripts and dockerfiles.  Backward compatible
change and proxy will not be used unless environment variable
is supplied to docker build command.

Fixes bug 1858

Change-Id: Ibd25bd1c145b8d43eeb85c5c952aec30ebcce1fc
Signed-off-by: beierlm <mark.beierl@canonical.com>
diff --git a/tools/local-build.sh b/tools/local-build.sh
index 0898518..9c40272 100755
--- a/tools/local-build.sh
+++ b/tools/local-build.sh
@@ -16,6 +16,7 @@
 # limitations under the License.
 #######################################################################################
 
+APT_PROXY=""
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
 HTTPDDIR="$( cd "${HOME}/snap/qhttp/common" &> /dev/null && pwd )"
 HTTPPORT=8000
@@ -30,6 +31,7 @@
     while [ $# -gt 0 ] ; do
         case $1 in
             --debug) set -x ;;
+            --apt-proxy) APT_PROXY="$2" && shift ;;
             --help | -h) show_help && exit 0 ;;
             --httpddir) HTTPDIR="$2" && shift;;
             --install-local-registry) 'install_local_registry' ;;
@@ -67,8 +69,9 @@
 
 OPTIONS:
   --help                        display this help message
+  --apt-proxy                   provide an apt proxy to docker build steps
   --debug                       enable set -x for this script
-  --install-local-registry     install and enable Microk8s local registry on port 32000
+  --install-local-registry      install and enable Microk8s local registry on port 32000
   --install-microstack          install Microstack and configure to run robot tests
   --install-qhttpd              install QHTTPD as an HTTP server on port ${HTTPPORT}
   --kubecfg                     path to kubecfg.yaml (uses Charmed OSM by default)
@@ -171,7 +174,12 @@
         print_section "Building ${MODULE}"
         cd ${MODULE}
         find . -name '*.deb' -exec rm -v {} \;
-        docker build ${NO_CACHE} -t ${MODULE,,}-stage2 .
+
+        BUILD_ARGS=""
+        if [ ! -z $APT_PROXY ] ; then
+            BUILD_ARGS="${BUILD_ARGS}--build-arg APT_PROXY=${APT_PROXY} "
+        fi
+        docker build ${NO_CACHE} ${BUILD_ARGS} -t ${MODULE,,}-stage2 .
 
         STAGES="stage-build.sh"
         if [ ! -z $TESTS ] ; then
@@ -217,6 +225,10 @@
     print_section "Performing Stage 3"
     MODULES=$(_find_module_dockerfile $1)
     BUILD_ARGS=""
+    if [ ! -z $APT_PROXY ] ; then
+        BUILD_ARGS="${BUILD_ARGS}--build-arg APT_PROXY=${APT_PROXY} "
+    fi
+
     HOSTIP=$(ip -4 addr show docker0 | grep -Po 'inet \K[\d.]+')
     for file in ~/snap/qhttp/common/*.deb ; do
         file=`basename ${file}`