Workaround for puppet-ceph zuul-cloning

Currently, puppet-ceph stable/hammer CI tries to clone Puppet OpenStack
modules using stable/hammer branch but they don't have it, only
puppet-ceph does.
We need to override ZUUL_BRANCH with a fake 'stable/mitaka' for Puppet
OpenStack modules and then checkout 'stable/hammer' for puppet-ceph.

This workaround will allow us to:
* test puppet-ceph/hammer with mitaka modules
* test puppet-ceph/master with newton and beyond modules

Note: for our r10k users, no problem, they use git to checkout the right
branch, so they don't have the bug.

Change-Id: I004ee95e6bd97992aeebd08447396e3b8a29e09f

functions

@@ -27,6 +27,16 @@ clonemap:
     dest: '$PUPPETFILE_DIR/\2'
 EOF
 
+  # Workaround for puppet-ceph, where we need to checkout
+  # OpenStack modules from stable/mitaka when working on stable/hammer.
+  # Ceph Hammer works with Mitaka and before.
+  # Ceph Jewel works with Newton and beyond.
+  if [ "$ZUUL_BRANCH" == "stable/hammer" ] || [ "$ZUUL_BRANCH" == "stable/mitaka" ]; then
+      PUPPET_CEPH_ZUUL_BRANCH='stable/hammer'
+  else
+      PUPPET_CEPH_ZUUL_BRANCH=$ZUUL_BRANCH
+  fi
+
   # Periodic jobs run without ref on master
   ZUUL_REF=${ZUUL_REF:-None}
   ZUUL_BRANCH=${ZUUL_BRANCH:-master}
@@ -36,6 +46,7 @@ EOF
   )
   /usr/zuul-env/bin/zuul-cloner -m clonemap.yaml \
     --cache-dir /opt/git \
+    --project-branch openstack/puppet-ceph=$PUPPET_CEPH_ZUUL_BRANCH \
     --zuul-ref $ZUUL_REF \
     --zuul-branch $ZUUL_BRANCH \
     --zuul-url $ZUUL_URL \