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#3478 multiple domain support fails for external domain
This issue is reported in xcat mailinglist, here is the details:
I have updated xCAT from 2.7 to 2.8 to use the new support for multiple
domains. We are using two cluster-internal domains and one external
domain. When I run "makedns -n" now, xCAT also creates a zone for hosts
of this external domain which then results in resolution failures
(forwarders are set correctly). When I comment out this zone in
/etc/named.conf, everything works as expected. How can I configure xCAT
to omit creating this zone entry?
Discussion
The case here is the customer wants an external domain to be listed in the /etc/resolv.conf on the compute nodes(generated by dhcp automatically), while at the same time, he does not want this external domain to be added as dns zone though the external net has been defined in the xcat network table.
The existing logic is to create dns zones for ALL the defined nets in xcat networks table, but for this requirement, seems we need find out a way to identify which nets will become dns zones which will not. The fix in my mind is we could use networks.nameservers to exclude the external net, that's why I asked Markus to confirm the information below. if the networks.nameserver is something other than any IPs on mn or <xcatmaster> keyword, then it indicates this network does not need to become dns zone on mn.</xcatmaster>
For example,
The mn has 3 interfaces, configured as 9.114.34.225/24(external.domain), 10.1.0.1/16(domain1.cluster.com) and 20.1.0.1/16(domain2.cluster.com), so the networks table looks like:
netname,net,mask,mgtifname,gateway,dhcpserver,tftpserver,nameservers,ntpservers,logservers,dynamicrange,staticrange,staticrangeincrement,nodehostname,ddnsdomain,vlanid,domain,comments,disable
"10_1_0_0-255_255_255_0","10.1.0.0","255.255.0.0","eth0","<xcatmaster>",,"10.1.0.225","10.1.0.1",,,,,,,,,"domain1.cluster.com",,
"20_1_0_0-255_255_255_0","10.1.0.0","255.255.0.0","eth1","<xcatmaster>",,"20.1.0.225","20.1.0.1",,,,,,,,,"domain2.cluster.com",,
"9_114_34_0-255_255_255_0","9.114.34.0","255.255.255.0","eth2","9.114.34.254",,"9.114.34.225","9.114.1.1",,,,,,,,,"external.com",,</xcatmaster></xcatmaster>
The networks.nameservers for the external net is 9.114.1.1(the samw as site.forwarders), it's not any IPs configured on the mn or "xcatmaster"(for hierarchy), so we can exclude this net before we create dns zones.
This is the same issue I am facing with customers as well, and the ticket 3571 also reflects some of the issues
The solution is to exclude the net configured with an external nameserver from dns zones.
xcat 2.9: fixed in revision 16580.
xcat 2.8.2 fixed in revision 16581.