Merge "Allow source-repositories to be disabled completely"

elements/redhat-common/pre-install.d/02-lsb

@@ -3,4 +3,8 @@
 set -eu
 set -o pipefail
 
+if [ -z "${NO_SOURCE_REPOSITORIES:-}" ]; then
     install -m 0755 -o root -g root /opt/stack/lsb-release/lsb_release /usr/local/bin
+else
+    install-packages redhat-lsb-core
+fi

elements/source-repositories/README.md

@@ -103,3 +103,7 @@ The base url for all git repositories can be set by use of:
 So setting DIB\_GITREPOBASE=https://github.com/ when the repo location is set
 to http://git.openstack.org/openstack/nova.git will result in use of the
 https://github.com/openstack/nova.git repository.
+
+When doing image builds in environments where external resources are not allowed,
+it is possible to disable fetching of all source repositories by including an
+element in the image that sets NO_SOURCE_REPOSITORIES=1 in an environment.d script.

elements/source-repositories/extra-data.d/98-source-repositories

@@ -3,6 +3,11 @@
 set -eu
 set -o pipefail
 
+# Don't provide any source repositories in environments where they are not allowed
+if [ -n "${NO_SOURCE_REPOSITORIES:-}" ]; then
+    exit 0
+fi
+
 # If the old cache exists, move it to the new name
 function make_new_cache(){
     local OLD_CACHE_BASE=$1