Updating Cobbler on RHEL5 to Import ESXi5 for PXE Install

So you want to play with ESXi5, but on RHEL5, today, the latest version of cobbler (2.2.1?) doesn't yet support it.  Cobbler 2.2.3 does, though, but it's not available at all yet.  Nooooooo.

Here's what you do:

1. install an RPMbuild of cobbler 2.2.3 .  Normally this is laughable-stupid, but we know the official one's coming eventually and we'll get the update from the official channels automatically.
   1. From the cobbler release_22 branch, go get the TGZ file for the latest 2.2 release:
      https://github.com/cobbler/cobbler/tarball/release22
   2. unpack that
      tar -C /tmp -xf cobbler-cobbler-cobbler-2.2.3-2-0-g80d646a.tar.gz(or just do it all in one go:
        wget -qO-  https://github.com/cobbler/cobbler/tarball/release22 | tar -C /tmp -xzf - )
   3. change and build it
      make -C /tmp/cobbler-cobbler-80d646a  rpms
   4. if you're me, you'll then remake it just to get the right apt repo, but hey.  People like to make things inside-out, and forget that the packaging is on the outside of the build.  Be nice to them, though, as they may be amateurs, and it's easy like rolling a stop-sign.
   5. install cobbler over what you have:
      rpm -Uvh  /tmp/cobbler-cobbler-80d646a/rpm-build/cobbler-2.2.3-2.noarch.rpm
   6. watch it fail when you do a cobbler check due to a missing and unreported dependency:
      cobbler check
   7. install said dependency, re-run cobbler check, think disapproving thoughts of the packagers:
      yum -y install python-ctypes
      cobbler check
2. grab your ESXi5 ISO
3. import that
   mount -o loop VMware-VMvisor-Installer-5.0.0.update01-623860.x86_64.iso /mnt/cdrom
   cobbler import -name esxi5 --path /mnt/cdrom/
4. rejoice
   more beer

It really is that easy, once you have a cheat-sheet.  Now go hack up a decent esxi5 KS and start installing like a boss.

Upgrading Cobbler from 2.0 to 2.2 -- and overcoming WSGI woes

If you've used Cobbler for a while, you'll want to upgrade it.  Naturally!

There's a problem with the upgrade, though:  the 2.0 version seems to use mod_python, and the new one uses mod_wsgi.  No problem, right?  So you install mod_wsgi as part of the process:

# service httpd start
Starting httpd: Syntax error on line 10 of /etc/httpd/conf.d/cobbler.conf:
Invalid command 'WSGIScriptAliasMatch', perhaps misspelled or defined by a
module not included in the server configuration
                                                           [FAILED]

So your server won't start.  Yay!

What's really going on is

1. mod_python and mod_wsgi don't play well together
2. mod_wsgi is impotent on install and needs activation
3. mod_python is still the go-to for rendering the configs, which now use syntax it can't handle

The remedy is simple:

1. remove mod_python.  It can't be used, so let's get it out to avoid dep- and other issues.
   
   

   rpm -e mod_python

2. create a mod_wsgi config
   
   

   cat > /etc/httpd/conf.d/05-load-wsgi.conf
   LoadModule wsgi_module modules/mod_wsgi.so
   

3. restart httpd
   
   

   service httpd restart

And that's it:

Stopping httpd:                                            [FAILED]
Starting httpd:                                            [  OK  ]

And you're back up and running.

Is it disappointing that it doesn't Just Work?  For sure.  Could you figure it out if you were a mod_python user or an expert, and knew the hell WSGi was?  Maybe.  But I'm not, and I think that as an app user it's not really on me to be an expert.  You may argue how proficient one needs to be to use any device, but I'm thinking it's not ready for prime-time yet.  Boo!

NoStorage and Kickstart - How to Specify Multiple HBA Modules

When kickstarting, you have the option of using 'nostorage' on the PXE command line to prevent storage HBA drivers from loading -- you can do the same to NICs, but it's not as interesting, not as common and the command line is dumber.

default linux
prompt 0
timeout 1
label linux
     kernel /images/centos55-x86_64/vmlinuz
     ipappend 2
     append initrd=/images/centos55-x86_64/initrd.img ksdevice=eth0 lang= kssendmac nostorage text ks=http://archive/cblr/svc/op/ks/system/Bish-PXETest

See that?  NoStorage.  Okay.

So what if you want to use the same kickstart for different machines?  For different HBAs ?  Normally you're screwed.  This won't work, either:

device scsi ahci
device scsi mptspi
device scsi cciss

Specifying the HBA drivers on multiple lines should work, but it's not that simple -- doing so makes it choose the first one and ignore every other invocation of the device line.  This does work, though:

device scsi ahci:mptspi:cciss

See the colons? There you go.  It allows/forces you to choose the order, so plan carefully.