Added ping_check and ssh_check functions and use it in exercise.sh

Change-Id: I69d41c9db527f60f250b6af36b2d8e9d0dd39684
diff --git a/stack.sh b/stack.sh
index 3fc3204..8797a63 100755
--- a/stack.sh
+++ b/stack.sh
@@ -1950,14 +1950,14 @@
     # Create a small network
     # Since quantum command is executed in admin context at this point,
     # ``--tenant_id`` needs to be specified.
-    NET_ID=$(quantum net-create --tenant_id $TENANT_ID net1 | grep ' id ' | get_field 2)
+    NET_ID=$(quantum net-create --tenant_id $TENANT_ID "$PRIVATE_NETWORK_NAME" | grep ' id ' | get_field 2)
     SUBNET_ID=$(quantum subnet-create --tenant_id $TENANT_ID --ip_version 4 --gateway $NETWORK_GATEWAY $NET_ID $FIXED_RANGE | grep ' id ' | get_field 2)
     if is_service_enabled q-l3; then
         # Create a router, and add the private subnet as one of its interfaces
         ROUTER_ID=$(quantum router-create --tenant_id $TENANT_ID router1 | grep ' id ' | get_field 2)
         quantum router-interface-add $ROUTER_ID $SUBNET_ID
         # Create an external network, and a subnet. Configure the external network as router gw
-        EXT_NET_ID=$(quantum net-create ext_net -- --router:external=True | grep ' id ' | get_field 2)
+        EXT_NET_ID=$(quantum net-create "$PUBLIC_NETWORK_NAME" -- --router:external=True | grep ' id ' | get_field 2)
         EXT_GW_IP=$(quantum subnet-create --ip_version 4 $EXT_NET_ID $FLOATING_RANGE -- --enable_dhcp=False | grep 'gateway_ip' | get_field 2)
         quantum router-gateway-set $ROUTER_ID $EXT_NET_ID
         if is_quantum_ovs_base_plugin "$Q_PLUGIN" && [[ "$Q_USE_NAMESPACE" = "True" ]]; then
@@ -1975,10 +1975,10 @@
 
 elif is_service_enabled mysql && is_service_enabled nova; then
     # Create a small network
-    $NOVA_BIN_DIR/nova-manage network create private $FIXED_RANGE 1 $FIXED_NETWORK_SIZE $NETWORK_CREATE_ARGS
+    $NOVA_BIN_DIR/nova-manage network create "$PRIVATE_NETWORK_NAME" $FIXED_RANGE 1 $FIXED_NETWORK_SIZE $NETWORK_CREATE_ARGS
 
     # Create some floating ips
-    $NOVA_BIN_DIR/nova-manage floating create $FLOATING_RANGE
+    $NOVA_BIN_DIR/nova-manage floating create $FLOATING_RANGE --pool=$PUBLIC_NETWORK
 
     # Create a second pool
     $NOVA_BIN_DIR/nova-manage floating create --ip_range=$TEST_FLOATING_RANGE --pool=$TEST_FLOATING_POOL