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/docker/RO/Dockerfile b/docker/RO/Dockerfile
index 39462de..b2f32a4 100644
--- a/docker/RO/Dockerfile
+++ b/docker/RO/Dockerfile
@@ -1,23 +1,28 @@
-##
-# Copyright 2019 ETSI
+#######################################################################################
+# Copyright ETSI Contributors and Others.
 #
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License. You may obtain
-# a copy of the License at
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-#         http://www.apache.org/licenses/LICENSE-2.0
+#    http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations
-# under the License.
-##
-
-########################################################################
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#######################################################################################
 
 FROM ubuntu:18.04 as INSTALL
 
+ARG APT_PROXY
+RUN if [ ! -z $APT_PROXY ] ; then \
+    echo "Acquire::http::Proxy \"$APT_PROXY\";" > /etc/apt/apt.conf.d/proxy.conf ;\
+    echo "Acquire::https::Proxy \"$APT_PROXY\";" >> /etc/apt/apt.conf.d/proxy.conf ;\
+    fi
+
 RUN DEBIAN_FRONTEND=noninteractive apt-get --yes update && \
     DEBIAN_FRONTEND=noninteractive apt-get --yes install \
     gcc=4:7.4.* \