X-Git-Url: http://pere.pagekite.me/gitweb/homepage.git/blobdiff_plain/e22781370f42c3479c619ecbc275ef2e7c64099e..40ff9fcec918fec87e73eae321520cbe14e9032f:/blog/index.rss diff --git a/blog/index.rss b/blog/index.rss index 961899c3d6..bcb8a035c6 100644 --- a/blog/index.rss +++ b/blog/index.rss @@ -6,6 +6,72 @@ http://people.skolelinux.org/pere/blog/ + + Combining PowerDNS and ISC DHCP LDAP objects + http://people.skolelinux.org/pere/blog/Combining_PowerDNS_and_ISC_DHCP_LDAP_objects.html + http://people.skolelinux.org/pere/blog/Combining_PowerDNS_and_ISC_DHCP_LDAP_objects.html + Wed, 14 Jul 2010 23:45:00 +0200 + +<p>For a while now, I have wanted to find a way to change the DNS and +DHCP services in Debian Edu to use the same LDAP objects for a given +computer, to avoid the possibility of having a inconsistent state for +a computer in LDAP (as in DHCP but no DNS entry or the other way +around) and make it easier to add computers to LDAP.</p> + +<p>I've looked at how powerdns and dhcpd is using LDAP, and using this +information finally found a solution that seem to work.</p> + +<p>The old setup required three LDAP objects for a given computer. +One forward DNS entry, one reverse DNS entry and one DHCP entry. If +we switch powerdns to use its strict LDAP method (ldap-method=strict +in pdns-debian-edu.conf), the forward and reverse DNS entries are +merged into one while making it impossible to transfer the reverse map +to a slave DNS server.</p> + +<p>If we also replace the object class used to get the DNS related +attributes to one allowing these attributes to be combined with the +dhcphost object class, we can merge the DNS and DHCP entries into one. +I've written such object class in the dnsdomainaux.schema file (need +proper OIDs, but that is a minor issue), and tested the setup. It +seem to work.</p> + +<p>With this test setup in place, we can get away with one LDAP object +for both DNS and DHCP, and even the LTSP configuration I suggested in +an earlier email. The combined LDAP object will look something like +this:</p> + +<blockquote><pre> + dn: cn=hostname,cn=group1,cn=THINCLIENTS,cn=DHCP Config,dc=skole,dc=skolelinux,dc=no + cn: hostname + objectClass: dhcphost + objectclass: domainrelatedobject + objectclass: dnsdomainaux + associateddomain: hostname.intern + arecord: 10.11.12.13 + dhcphwaddress: ethernet 00:00:00:00:00:00 + dhcpstatements: fixed-address hostname + ldapconfigsound: Y +</pre></blockquote> + +<p>The DNS server uses the associateddomain and arecord entries, while +the DHCP server uses the dhcphwaddress and dhcpstatements entries +before asking DNS to resolve the fixed-adddress. LTSP will use +dhcphwaddress or associateddomain and the ldapconfig* attributes.</p> + +<p>I am not yet sure if I can get the DHCP server to look for its +dhcphost in a different location, to allow us to put the objects +outside the "DHCP Config" subtree, but hope to figure out a way to do +that. If I can't figure out a way to do that, we can still get rid of +the hosts subtree and move all its content into the DHCP Config tree +(which probably should be renamed to be more related to the new +content. I suspect cn=dnsdhcp,ou=services or something like that +might be a good place to put it.</p> + +<p>If you want to help out with implementing this for Debian Edu, +please contact us on debian-edu@lists.debian.org.</p> + + + Idea for storing LTSP configuration in LDAP http://people.skolelinux.org/pere/blog/Idea_for_storing_LTSP_configuration_in_LDAP.html @@ -625,36 +691,5 @@ håndheves strengt.</p> - - Officeshots taking shape - http://people.skolelinux.org/pere/blog/Officeshots_taking_shape.html - http://people.skolelinux.org/pere/blog/Officeshots_taking_shape.html - Sun, 13 Jun 2010 11:40:00 +0200 - -<p>For those of us caring about document exchange and -interoperability, <a href="http://www.officeshots.org/">OfficeShots</a> -is a great service. It is to ODF documents what -<a href="http://browsershots.org/">BrowserShots</a> is for web -pages.</p> - -<p>A while back, I was contacted by Knut Yrvin at the part of Nokia -that used to be Trolltech, who wanted to help the OfficeShots project -and wondered if the University of Oslo where I work would be -interested in supporting the project. I helped him to navigate his -request to the right people at work, and his request was answered with -a spot in the machine room with power and network connected, and Knut -arranged funding for a machine to fill the spot. The machine is -administrated by the OfficeShots people, so I do not have daily -contact with its progress, and thus from time to time check back to -see how the project is doing.</p> - -<p>Today I had a look, and was happy to see that the Dell box in our -machine room now is the host for several virtual machines running as -OfficeShots factories, and the project is able to render ODF documents -in 17 different document processing implementation on Linux and -Windows. This is great.</p> - - -