From: Matt Amos <zerebubuth@gmail.com>
Date: Thu, 27 Aug 2015 18:29:59 +0000 (+0100)
Subject: Allow pinning kernel versions to work around hardware / driver issues
X-Git-Url: https://git.openstreetmap.org/chef.git/commitdiff_plain/d1be18e9426db54d3cf367855ee95fd8ed117e3b?hp=3c54ec033cbaa0e1cb58c7157c5741d857e36613

Allow pinning kernel versions to work around hardware / driver issues

Sometimes hardware issues or driver issues are fixed or broken in
specific kernel versions, so it's handy to be able to pin the
version to a known-working one while the problem is sorted out or
a proper fix is found.

This does this by ensuring that the particular kernel version package
is installed and that the grub configuration boots that as the default.

For context, see https://github.com/openstreetmap/operations/issues/45
---

diff --git a/cookbooks/hardware/attributes/default.rb b/cookbooks/hardware/attributes/default.rb
index f80e6a528..26f126abd 100644
--- a/cookbooks/hardware/attributes/default.rb
+++ b/cookbooks/hardware/attributes/default.rb
@@ -1,5 +1,6 @@
 default[:hardware][:modules] = %w(loop lp rtc)
 default[:hardware][:grub][:cmdline] = %w(nomodeset)
+default[:hardware][:grub][:kernel] = :latest
 default[:hardware][:sensors] = {}
 
 if node[:dmi] && node[:dmi][:system]
diff --git a/cookbooks/hardware/recipes/default.rb b/cookbooks/hardware/recipes/default.rb
index 3c2f84a68..620c7d58b 100644
--- a/cookbooks/hardware/recipes/default.rb
+++ b/cookbooks/hardware/recipes/default.rb
@@ -120,6 +120,16 @@ unless unit.nil?
   end
 end
 
+# if we need a different / special kernel version to make the hardware
+# work (e.g: https://github.com/openstreetmap/operations/issues/45) then
+# ensure that we have the package installed. the grub template will
+# make sure that this is the default on boot.
+unless node[:hardware][:grub][:kernel] == :latest
+  package "linux-image-#{node[:hardware][:grub][:kernel]}-generic"
+  package "linux-image-extra-#{node[:hardware][:grub][:kernel]}-generic"
+  package "linux-headers-#{node[:hardware][:grub][:kernel]}-generic"
+end
+
 if File.exist?("/etc/default/grub")
   execute "update-grub" do
     action :nothing
diff --git a/cookbooks/hardware/templates/default/grub.erb b/cookbooks/hardware/templates/default/grub.erb
index 1c19cf684..d69a870b9 100644
--- a/cookbooks/hardware/templates/default/grub.erb
+++ b/cookbooks/hardware/templates/default/grub.erb
@@ -1,7 +1,23 @@
 # DO NOT EDIT - This file is being maintained by Chef
 
-# Boot the first entry by default
+# Boot the first entry by default, unless we have configured
+# it to boot a specific version.
+<% if node[:hardware][:grub][:kernel] == :latest %>
 GRUB_DEFAULT="0"
+<% else
+  df = Mixlib::ShellOut.new("df /boot/grub/grub.cfg | tail -n 1 | awk '{print $1;}'")
+  df.run_command
+  df.error!
+  root=df.stdout
+
+  blkid = Mixlib::ShellOut.new("blkid -o value -s UUID #{root}")
+  blkid.run_command
+  blkid.error!
+  uuid=blkid.stdout
+
+  version="#{node[:hardware][:grub][:kernel]}-generic" %>
+GRUB_DEFAULT="gnulinux-advanced-<%= uuid %>>gnulinux-<%= version %>-advanced-<%= uuid %>"
+<% end %>
 
 # Wait two seconds before booting the default entry
 GRUB_TIMEOUT="2"
diff --git a/roles/pummelzacken.rb b/roles/pummelzacken.rb
index 5d4647130..d7ae5cd6b 100644
--- a/roles/pummelzacken.rb
+++ b/roles/pummelzacken.rb
@@ -52,6 +52,14 @@ default_attributes(
     :redirects => {
       :reverse => "poldi.openstreetmap.org"
     }
+  },
+  :hardware => {
+    :grub => {
+      # lock kernel to 3.16.0-46 due to some issue with igb driver
+      # see https://github.com/openstreetmap/operations/issues/45
+      # for more information.
+      :kernel => "3.16.0-46"
+    }
   }
 )