euca_conf does not properly register new nodes

[Stefan Bucur]

When euca_conf --discover-nodes or --register-nodes adds a new node to the NODES list in eucalyptus.conf, the node will not be added if its name is a substring of a name of any previously added nodes.

The bug in the euca_conf shell script is here:

# NODES list
                if ! echo "${NODES}"|grep "${NEWNODE}" > /dev/null ; then
                        # node is not present: we need to add it
                        NODES="${NODES} $NEWNODE"
                        change_var_value $FILE NODES "${NODES}"
                fi

Here, grep will match any matching substring, *even if it does not form a full node name*.

The problem is significant in particular for IP addresses, when it is likely that one IP address to be the substring of another. In my case, it was: 10.0.10.1 and 10.0.10.10. After I added the node 10.0.10.10, euca_conf refused to register 10.0.10.1 in eucalyptus.conf, even if its output was successful.

A quick solution would be to add the "-w" parameter to grep, but I'm not yet sure it works in every situation (e.g. when ${NEWNODE} contains regexp language symbols).