[chef] Re: apt-get update strategy

[Luke Biddell < >]

Thanks for all the suggestions chaps. I'll certainly check them all out.

I had a scribble on Friday (that's what Friday's are for?) and hacked
up my own provider.

I've added it to our existing apt cookbook. It's intended as a drop-in
replacement for package. If you do an install it only does an update
if the package isn't installed. Ie, the first package to be installed
will trigger the only update for that run. If you do a package upgrade
it makes sure an upgrade is done once only. If all packages are
converged, no update is done.

The flag to indicate if an update has been done is stored on the node
and has to be reset at the start of each run. Is there a better way of
setting transient attributes for the run?

I've posted the code here in case it's any use to anyone else. I'm
going to commit it in dev here and see what comes out in the wash. I'm
sure I've broken/abused something.

-------------------------------------------------------------------------------
- apt/resources/pkg.rb

actions :install, :upgrade, :remove, :purge
attribute :name, :kind_of => String

-------------------------------------------------------------------------------
- apt/providers/pkg.rb


action :install do
  if(!system("dpkg-query -W -f='${Status}' 

 
 > /dev/null"))
    process_package :install
  end
end

action :upgrade do
  process_package :upgrade
end

action :remove do
  package @new_resource.name do
    action :remove
  end
end

action :purge do
  package @new_resource.name do
    action :purge
  end
end

private

def process_package (mode)
  Chef::Log.debug("#{mode} of package 

 
 requested")
  if(!node[:apt_update_performed_this_chef_run])
    Chef::Log.debug("apt-get update required for this run, performing")
    execute "apt-get update"
    node[:apt_update_performed_this_chef_run] = true
  else
    Chef::Log.debug("apt-get update already performed for this run")
  end
  package @new_resource.name do
    action  mode
  end
  @new_resource.updated_by_last_action(true)
end





On 27 March 2011 14:46, Bryan McLellan 
<
 >
 wrote:
> On Fri, Mar 25, 2011 at 2:45 AM, Luke Biddell 
> <
 >
>  wrote:
>> So what I'd ideally like is to be able to trigger an apt-get update on
>> the first package which requires installing. If no packages require
>> installing, no apt-get update is performed. The fact an update has
>> been performed needs to be recorded as we don't want to do it for
>> every package that's installed as it will kill performance. Once is
>> enough per chef run unless we add/remove a sources.list.d entry (which
>> I already handle using :notifies).
>
> There are a number of strategies. Here's another I used to do.
>
> Only trigger an apt-get update when a repo or key is added, otherwise
> rely on Ubuntu to run a daily apt-get update but run it ourselves if
> we need to. Note that I was silently rescuing failures as well.
>
> # Run apt-get update to create the stamp file
> execute "apt-get-update" do
>  ignore_failure true
>  epic_fail true
>  command "apt-get update"
>  not_if do File.exists?('/var/lib/apt/periodic/update-success-stamp') end
> end
>
> # provides /var/lib/apt/periodic/update-success-stamp on apt-get update
> package "update-notifier-common" do
>  ignore_failure true
>  notifies :run, resources(:execute => "apt-get-update"), :immediately
> end
>
> execute "apt-get-update-periodic" do
>  ignore_failure true
>  epic_fail true
>  command "apt-get update"
>  only_if do
>    File.exists?('/var/lib/apt/periodic/update-success-stamp') &&
>    File.mtime('/var/lib/apt/periodic/update-success-stamp') < Time.now - 
> 86400
>  end
> end
>