CI - Depends-On support

This patch will use the Depends-On info stored in the ZUUL_CHANGES
env var to update the Berksfile to a local patch and then use
zuul-cloner to pull down that dependency.

To use Depends-On, add the following to your commit message AFTER
the description and BEFORE the change id and bug/blueprint ref.
"Depends-On: <id>"
The id is the change id of the gerrit patch this patch depends on.

Change-Id: I13a5ef21733cdd00841dc1ec1afe7442b2dc8831

bootstrap.sh

@@ -11,3 +11,43 @@ sudo dpkg -i $chefdk
 
 ## workaround to fix redhat fauxhai permission issue (can be removed with fauxhai > 2.3 in chefdk)
 sudo chef exec ruby -e "require 'fauxhai'; Fauxhai.mock(platform:'redhat', version:'7.1')"
+
+# The following will handle cross cookbook patch dependencies via the Depends-On in commit message
+
+# ZUUL_CHANGES has a ^ separated list of patches, the last being the current patch.
+# The Depends_On will add patches to the front of this list.
+echo $ZUUL_CHANGES
+# Convert string list to array
+cookbooks=(${ZUUL_CHANGES//^/ })
+# Remove the last one as it's the current cookbook
+# TODO(MRV) At some point we could consider removing the gerrit-git-prep step from the rake job
+# and also doing that patch clone with zuul-cloner.  After gerrit-git-prep is removed, need to
+# remove this unset line and adjust the clone map to have the base patch put into the current dir.
+unset cookbooks[${#cookbooks[@]}-1]
+
+# Create clone map
+cat > clonemap.yaml <<EOF
+clonemap:
+ - name: 'openstack/(.*)'
+   dest: '\1'
+EOF
+
+# Create list of Depends-On cookbook names and update Berksfile entry for each
+cookbook_projects=""
+for cookbook_info in "${cookbooks[@]}"; do
+  [[ $cookbook_info =~ openstack/([a-z-]*):.* ]]
+  cookbook_name="${BASH_REMATCH[1]}"
+  cookbook_projects+=" openstack/$cookbook_name"
+  sed -i -e "s|github: [\"\']openstack/$cookbook_name[\"\']|path: '../$cookbook_name'|" Berksfile
+done
+
+# Allow the zuul cloner to pull down the necessary Depends-On patches
+if [ "$cookbook_projects" ]
+then
+  sudo -E /usr/zuul-env/bin/zuul-cloner \
+    -m clonemap.yaml \
+    --cache-dir /opt/git \
+    --workspace /home/jenkins/workspace/ \
+    git://git.openstack.org \
+    $cookbook_projects
+fi