Clean up security groups in exercises

* fix problem with deleting security groups too early in
  floating_ips.sh and euca.sh
* create and clean up security groups
* cosmetic cleanups

Change-Id: Ie45e03f889c540ec83f27a02b10e787060c5d4d7
diff --git a/exercises/euca.sh b/exercises/euca.sh
index 9f7aed1..fb052dd 100755
--- a/exercises/euca.sh
+++ b/exercises/euca.sh
@@ -43,6 +43,9 @@
 # Boot this image, use first AMI-format image if unset
 DEFAULT_IMAGE_NAME=${DEFAULT_IMAGE_NAME:-ami}
 
+# Security group name
+SECGROUP=${SECGROUP:-euca_secgroup}
+
 
 # Launching a server
 # ==================
@@ -50,9 +53,6 @@
 # Find a machine image to boot
 IMAGE=`euca-describe-images | grep machine | grep ${DEFAULT_IMAGE_NAME} | cut -f2 | head -n1`
 
-# Define secgroup
-SECGROUP=euca_secgroup
-
 # Add a secgroup
 if ! euca-describe-groups | grep -q $SECGROUP; then
     euca-add-group -d "$SECGROUP description" $SECGROUP
@@ -119,14 +119,13 @@
     die "Failure terminating instance $INSTANCE"
 
 # Assure it has terminated within a reasonable time
-if ! timeout $TERMINATE_TIMEOUT sh -c "while euca-describe-instances $INSTANCE | grep -q running; do sleep 1; done"; then
+if ! timeout $TERMINATE_TIMEOUT sh -c "while euca-describe-instances $INSTANCE | grep -q $INSTANCE; do sleep 1; done"; then
     echo "server didn't terminate within $TERMINATE_TIMEOUT seconds"
     exit 1
 fi
 
 # Delete group
-euca-delete-group $SECGROUP || \
-    die "Failure deleting security group $SECGROUP"
+euca-delete-group $SECGROUP || die "Failure deleting security group $SECGROUP"
 
 set +o xtrace
 echo "*********************************************************************"