Red Hat Bugzilla – Bug 131142
unable to select which interface to bind to from lock_gulmd
Last modified: 2010-01-11 21:57:31 EST
Description of problem: There is no capability in lock_gulmd to select the ethernet intrerface to bind to. The code is as follows: void set_myID(void) { /* cute tricks to set the default name and IP. */ gethostname(myName, 256); /* lookup my ip from my full name. */ if( get_ip_for_name(myName, &myIP) != 0 ) die(ExitGulm_InitFailed, "Failed to find IP for my name (%s)\n", myName); } A workaround exists to trick out lock_gulmd to bind to another interface (although this is quite ugly). The workaround is to switch the hostname of the node before starting lock_gulmd, and then revert back to the original hostname after lock_gulmd has started. This will require that you have already named the host in nodes.ccs and /etc/hosts and/or dns. Workaround: 1. saved_name=$(hostname) 2. hostname $new_name 3. lock_gulmd 4. hostname $saved_name Users expect to be able to use any interface on their system, not just whatever resolves to gethostname(). Users in the field are using the workaround. (I know because I told them how to do it ;) It would be nice to provide a more robust and lessy kludgy way of doing this.
Created attachment 103190 [details] adds ability to specif ip/hostname or interface to bind to
patch looks pretty good. except that the getipbyiface() function should probably be in the utils_ip.c file.
question, did you try putting the ips that are on the second interface into the servers line instead of names?
nevermind. that won't work because gulm resloved back the name, which may not match when connecting to a server (which takes the name and resolves it to an ip to check, and that may not resolve to the original ip.)
ok, this feels a bit off. Its kinda a hack on a very old tight binding in gulm. one name == one ip == one machine. Now this isn't true in many setups, esspcially those with multiple network devices. They typically have many ips, and this is what confuses gulm. I need to think about this some more, but I think the first step in the correct solution for this is to remove the ip from that above assumption.
have code in cvs head.
Adds an optional "usedev" key to a node in the nodes.ccs:nodes. Value of this key is a named device from the ip_interfaces section. If usedev is present, gulm will use the IP from that device in the ip_interfaces section. Otherwise it will grab th IP from libresolv (like before). ie: nodes{ foodad { ip_interfaces { wizzy = "1.2.3.4" } usedev = "wizzy" } }
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2005-466.html