Use prepared model and scripts if exist

Change-Id: I9186ad365f5f3f330a11930fecd0e18fd7465ae0
diff --git a/mirror-image/run.example.sh b/mirror-image/run.example.sh
index 8a51c73..a27455a 100755
--- a/mirror-image/run.example.sh
+++ b/mirror-image/run.example.sh
@@ -15,7 +15,7 @@
 export IMAGE_NAME="mcp-offline-mirror-$(date '+%Y-%m-%d-%H-%M-%S')"
 export PACKER_IMAGES_CACHE="${HOME}/packer_images_cache/"
 #
-export CLUSTER_MODEL="https://github.com/Mirantis/mcp-offline-model.git"
+export CLUSTER_MODEL="https://gerrit.mcp.mirantis.com/mcp/mcp-offline-model"
 export CLUSTER_MODEL_REF="master"
 export CLUSTER_NAME="mcp-offline"
 
@@ -29,7 +29,7 @@
 export APT_MIRANTIS_GPG="http://apt.mirantis.com/public.gpg"
 export APT_MIRANTIS_SALT_REPO="http://apt.mirantis.com/xenial/ ${BINARY_MCP_VERSION} salt "
 #
-export GIT_SALT_FORMULAS_SCRIPTS="https://github.com/salt-formulas/salt-formulas-scripts.git"
+export GIT_SALT_FORMULAS_SCRIPTS="https://gerrit.mcp.mirantis.com/salt-formulas/salt-formulas-scripts"
 export SCRIPTS_REF="master"
 #
 export APT_REPOSITORY=" deb [arch=amd64] ${APT_MIRANTIS_SALT_REPO} "
@@ -50,20 +50,22 @@
 
 export PACKER_LOG=1
 pushd config-drive
-  [ -d model ] && rm -rf model
-  git clone ${CLUSTER_MODEL} model/
-  pushd model
-    git fetch ${CLUSTER_MODEL} ${CLUSTER_MODEL_REF} && git checkout FETCH_HEAD
-    pushd classes/system
-      git submodule init
-      git submodule update
+  if [ ! -e model ]; then
+    git clone ${CLUSTER_MODEL} model/
+    pushd model
+      git fetch ${CLUSTER_MODEL} ${CLUSTER_MODEL_REF} && git checkout FETCH_HEAD
+      pushd classes/system
+        git submodule init
+        git submodule update
+      popd
     popd
-  popd
-  [ -d salt_scripts ] && rm -rf salt_scripts
-  git clone ${GIT_SALT_FORMULAS_SCRIPTS} salt_scripts/
-  pushd salt_scripts
+  fi
+  if [ ! -e salt_scripts ]; then
+    git clone ${GIT_SALT_FORMULAS_SCRIPTS} salt_scripts/
+    pushd salt_scripts
     git fetch ${GIT_SALT_FORMULAS_SCRIPTS} ${SCRIPTS_REF} && git checkout FETCH_HEAD
-  popd
+    popd
+  fi
 popd
 
 [ -f config-drive/cloudata.iso ] && rm -v config-drive/cloudata.iso