Add script to move between groups

Closes gpfs5-migration#30

user_migrate.sh

 #!/bin/bash
 
+group_options=(gpfs4 gpfs5)
+gpfs4_home="/gpfs4/data/user/home"
+gpfs5_home="/gpfs5/data/user/home"
+
 user=$1
 group_to=$2
 
 if [[ -z "${group_to}" ]]; then
   echo "Usage: $0 USER TARGET_GROUP"
   exit 1
-elif [[ "${group_to}" != "gpfs4" && "${group_to}" != "gpfs5" ]]; then
-  echo "Target group should be \"gpfs4\" or \"gpfs5\", got \"${group_to}\"."
+elif [[ ! " ${group_options[*]} " =~ [[:space:]]${group_to}[[:space:]] ]]; then
+  echo "Invalid target group"
+  echo "Available options: ${group_options[*]}, got ${group_to}"
   exit 1
 fi
 
-getent passwd "$user" > /dev/null 2&>1
-
-if [[ $? -ne 0 ]]; then
+if ! getent passwd "$user" > /dev/null 2>&1; then
   echo "The user $user does not exist"
   exit 1
 fi
@@ -21,17 +24,20 @@ fi
 cd /cm/shared/rabbitmq_agents || exit
 source venv/bin/activate
 
-
 if [[ "$group_to" == "gpfs4" ]]; then
   group_from=gpfs5
+  dir_from="$gpfs5_home/$user/"
+  dir_to="$gpfs4_home/$user"
 else
   group_from=gpfs4
+  dir_from="$gpfs4_home/$user/"
+  dir_to="$gpfs5_home/$user"
 fi
 
 if [[ -d "/$group_from/data/user/home/$user" ]]; then
   ./account_manager.py "$user" hold
 
-  rsync -a --delete "/$group_from/data/user/home/$user/" "/$group_to/data/user/home/$user"
+  rsync -a --delete "$dir_from" "$dir_to"
 
   ./group_manager.py "$user" -g "$group_to"
   ./group_manager.py "$user" -d -g "$group_from"