Dealing With Cobbler Signature Errors


I wanted to test out a couple of Brendan Gregg’s amazing eBPF scripts scripts this week. My home lab uses cobbler and ansible to provision systems and I was hoping to use Fedora 27 since it has a recent kernel. When I tried to import the Fedora 27 server DVD I received the following error:

$ cobbler import --name=fedora27 --arch=x86_64 --path=/mnt

task started: 2017-12-13_124734_import
task started (id=Media import, time=Wed Dec 13 12:47:34 2017)
Found a candidate signature: breed=redhat, version=rhel6
Found a candidate signature: breed=redhat, version=rhel7
Found a candidate signature: breed=redhat, version=fedora21
Found a candidate signature: breed=redhat, version=fedora20
Found a candidate signature: breed=redhat, version=fedora23
Found a candidate signature: breed=redhat, version=fedora22
Found a candidate signature: breed=redhat, version=fedora25
Found a candidate signature: breed=redhat, version=fedora24
Found a candidate signature: breed=redhat, version=fedora26
Found a candidate signature: breed=redhat, version=cloudlinux6
Found a candidate signature: breed=redhat, version=fedora16
Found a candidate signature: breed=redhat, version=fedora17
Found a candidate signature: breed=redhat, version=fedora18
Found a candidate signature: breed=redhat, version=fedora19
No signature matched in /var/www/cobbler/ks_mirror/fedora27-x86_64
!!! TASK FAILED !!!

Cobbler keeps a set of distribution signatures in /var/lib/cobbler/distro_signatures.json which you can view with the cobbler signature report option:

$ cobbler signature report --name=redhat

Currently loaded signatures:
redhat:
	cloudlinux6
	fedora16
	fedora17
	fedora18
	fedora19
	fedora20
	fedora21
	fedora22
	fedora23
	fedora24
	fedora25
	fedora26
	rhel4
	rhel5
	rhel6
	rhel7

Each signature in this file is a JSON object defining how a given distribution is laid out. To update the contents of this file (which typically fixes the missing signature issue) you can use cobbler signature update:

$ cobbler signature update

task started: 2017-12-13_132701_sigupdate
task started (id=Updating Signatures, time=Wed Dec 13 13:27:01 2017)
Successfully got file from https://cobbler.github.io/signatures/2.8.x/latest.json
*** TASK COMPLETE ***

Updating the signature file unfortunately didn’t fix my issue. A quick review of the official cobbler distro_signatures.json file shows that Fedora 27 hasn’t been added yet so it looks like I will be putting my JSON skills to good use tonight. I also filed a feature enhancement on github to get this added.

This article was posted by Matty on 2017-12-13 12:51:50 -0500 EST