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.

Maintaining Repos in Kickstarted Machines After Install

After you've installed a machine, its install-time repository config in /etc/yum.repos.d is pretty much set.

Bah, I say! Bah! Just keep it updated.

Kickstart (cobbler):

#set yumconfcronfilename = "/etc/cron.daily/50-yum-config-stanza"
cat << EOECYCS > $yumconfcronfilename
#!/bin/sh
$yum_config_stanza

sed -ne '
        /^baseurl=/{
                s/baseurl=/repomd /
                s://:__:
                s:/: :
                s:__://:
                p
        }
        ' /etc/yum.repos.d/cobbler-config.repo \
          > /etc/apt/sources.list.d/cobbler-config.list
EOECYCS
chmod a+x $yumconfcronfilename

If you're not running cobbler, set it into place by hand:

cat << EOECYCS > /etc/cron.daily/50-yum-config-stanza
#!/bin/sh
wget "http://archive/cblr/svc/op/yum/profile/centos5-i386-minimal" --output-document=/etc/yum.repos.d/cobbler-config.repo

sed -ne '
 /^baseurl=/{
  s/baseurl=/repomd /
  s://:__:
  s:/: :
  s:__://:
  p
 }
 ' /etc/yum.repos.d/cobbler-config.repo \
   > /etc/apt/sources.list.d/cobbler-config.list
EOECYCS

chmod a+x /etc/cron.daily/50-yum-config-stanza

That's dereferenced for you. The actual profile's going to be way off, though, so don't use that one verbatim. Find your own:

awk -F/ '/^url/{print $NF}' anaconda-ks.cfg

As usual, watch carefully for the way in which the 'new', 'better' blogspot editor makes an artistic puree of the quoted stuff;  grain of salt, kids.

Whither be Withered Stateless Linux?

I've been pocking at Stateless Linux for a while.

Probably since it was called Diskless Linux.  Names change.

Anyway, I stumbled over a stateless linux page referring to a tech preview in RHEL5, which sounds awesome.

Sadly it doesn't appear to be available.  "Install FC7," it says, not knowing that FC7's stereotypical 3-week support window closed at least a week ago, and thus any projects using it will simply not work.

So where did the Tech Preview go?  If it was a tech preview way back in 1992 or whenever RHEL5 was released, should it not be at least a tech preview now?

I worry that the Open Source Community has an attention span even shorter than mine.

False Start on Cobbler Repos -> Apt RepoMD statements

Man, I know so little python.  And while I hate it, I see that it's a deficiency I need to fix.  That sucks, but I may just find it useful eventually.

So I was poking around, and started to extend cobbler to feed an apt sources.list files the same as it does for a yum repo file when a given profile or system has supplemental repos attached. 

But all I did was start.  The curve's a bit high since I know so little, and I have so many other things I have to do -- like, for money.

Here's a tiny patch so far.  I'll find the rest eventually:

--- kickgen.py  2010/09/29 03:40:45     1.1
+++ kickgen.py  2010/09/29 07:06:23
@@ -175,10 +175,15 @@
         blended = utils.blender(self.api, False, obj)
         if is_profile:
            url = "http://%s/cblr/svc/op/yum/profile/%s" % (blended["http_server"], obj.name)
+           lru = "http://%s/cblr/svc/op/apt/profile/%s" % (blended["http_server"], obj.name)
         else:
            url = "http://%s/cblr/svc/op/yum/system/%s" % (blended["http_server"], obj.name)
+           lru = "http://%s/cblr/svc/op/apt/system/%s" % (blended["http_server"], obj.name)

-        return "wget \"%s\" --output-document=/etc/yum.repos.d/cobbler-config.repo\n" % (url)
+        ulines = "wget \"%s\" --output-document=/etc/yum.repos.d/cobbler-config.repo\n" % (url)
+#        ulines += "wget \"%s\" --output-document=/etc/apt/sources.list.d/cobbler-config.list\n" % (lru)
+
+        return ulines

     def generate_kickstart_for_system(self, sys_name):

Yeah, that's all I've got.  Lose the comment on the ulines+= line, and then find out the part where /op/apt/system/ actually rolls the template snippet for the apt sources.list file.  I see it here and there but can't nail down the bit in the code.  Frustrating, almost as much as running out of frivolity time.


Learning is fun, when I have time.

Kickstarting ESX VMs and Physical Hosts -- Knowing Which is Which

UPDATE: This method also does not work. Sorry.

Cobbler and kickstarting is my new cool toy.  I tinker with it FAR too much. I had a problem, though, that I need to install the vmware tools only on the VMs, and install smartmontools only on the physical hosts.  What's a guy to do?

After some digging, coding, hacking, testing, cursing, I finally discovered a decent switch I can use to identify a box by its mac.

Then I lost that code.

So I found another method.  This one's ugly as sin, but it may actually work.  Check this nasty-ass kung-fu:

#if ":".join($interfaces.eth0.mac_address.split(':')[0:3]) in "00:50:56 00:0C:29"

[code]

#end if

Yeah.  That's one ugly baby.  If Blogspot again truncates that line all to hell, remember the #if statement is all on the first line of 3.

Now to see how well it works.

Centos5-i386 -- LVM Root on a Kickstart?

I've gotta be doing something wrong.  But it looks good from so close to the problem.  Here's a snippet of the kickstart I'm using:

part pv.01  --size 32 --grow --asprimary
volgroup vg01 pv.01
logvol / --fstype ext3 --name=root --vgname=vg01 --size 10240

When it all comes down, though, it's a little screwed.  There's a pic.  The thing is, it's not really an LVM issue, since the space is there and the PV's been created.

A little investigation, though, shows the device /dev/vg01/root hasn't been created.  Simple fix?

lvm vgchange -a y

Then the devices are up.  It's too easy.  Bad news?  Can't happen in a kickstart.  The install pattern, as they say, is full, and it's missing the VG startup.

So where from here?

Auto-Updating Distro profile in Cobbler

As part of a very short, unsuccessful Fedora 13 test, I found it advantageous to set up an auto-updating distro.  Okay, given the release behaviour of Fedora vs, say, RHEL, an auto-updating distro profile for a distro which doesn't actually update is kinda pointless.  Work with me here, though.

How to do this in Cobbler?  Create a repo, which we can update automatically, and link the distro to that:

cobbler repo add --name fedora13-os-x86_64 --arch x86_64 \
  --mirror rsync://mirrors.kernel.org/fedora/releases/13/Fedora/x86_64/os

cobbler import --name fedora13 --arch x86_64 \
  --path /var/www/cobbler/repo_mirror/fedora13-os-x86_64 \
  --available-as http://10.10.4.1/cblr/repo_mirror/fedora13-os-x86_64 \
  --breed redhat --kickstart /etc/cobbler/centos-X.ks

Too easy.  Blah blah, test often, blah blah, change the IP to suit, etc.

Check the CommandLine Options in your PXE Booting Linux

I'm not sure if the grammar in the subject is the best it can be.

A question came up on a mailing list about command line options which can be passed to the linux installer at boot time.  The user in question is rolling out a series of new hosts with RocketRaid HBAs in them - for which I admire his courage where I gave up - and needs to push the driver disk to them at install time or they'll never see the root disks.  No, kickstart is not a viable option yet.

After some groveling through the options - and I suspect a RH employee who I fear had  to hold back for fear of breaching a Centos/RHEL condition - I think we got him exactly what he needs, which is awesome.

Want to look at those command line options in one go?  Try this:

zcat /tftpboot/images/centos5-x86_64/initrd.img | \
     cpio -iv --to-stdout sbin/loader|strings|less

Do that - adjusting for location - and start vgrepping.

For what it's worth, after jamming a fan onto my Adaptec 2405 (a Scythe Mini Kaze HTPC Silent Mini Fan 50MM 4500RPM 9.42CFM 26.09DBA 2 Pin W/ 3 Pin Adaptor, to be OCD about it) works like a charm.  Go get one of those and discard the HotPoint stuff, imho.