Re: Unnecessary changes when creating facts.yaml

[Ellison Marks]

I ran into the same thing. I think whoever made the snippet on the facts via YAML page was either relying on some feature of a previous version of ruby or simply didn't think the reordering was a problem. Given that they included this line in their example:

loglevel => debug,  # this is needed to avoid it being logged and reported on every run

I'm inclined toward the second option.

On Monday, December 3, 2012 2:39:33 AM UTC-8, Andrew Beresford wrote:

I have set up puppet to create a facts.yaml file for mcollective using the following line:

  content  => inline_template("<%= scope.to_hash.reject { |k,v| k.to_s =~ /(uptime.*|timestamp|.*free|macaddress.*|ipaddress)/ }.to_yaml %>"),

However, it is creating a lot of unnecessary changes by reordering the facts in the yaml output as you can see in the diff output between to runs;

--- facts.yaml 2012-12-03 10:25:15.389570751 +0000

+++ facts.yaml.copy 2012-12-03 10:24:31.982563969 +0000

@@ -5,14 +5,14 @@

   clientcert: rhel6test.shef.ac.uk

   rubyversion: "1.8.7"

   lsbdistdescription: "Red Hat Enterprise Linux Server release 6.3 (Santiago)"

-  architecture: x86_64

   boardmanufacturer: "Intel Corporation"

+  architecture: x86_64

   type: Other

   serialnumber: "VMware-42 26 2c 7e 64 54 65 e5-bd 53 81 d7 56 02 2e e4"

-  processorthreadcount: "1"

   lsbmajdistrelease: "6"

+  processorthreadcount: "1"

   title: "mcollective::server"

   lsbdistcodename: Santiago

   mcollective_serverpackage: mcollective

   id: root

At first I was thinking of just changing the template so that the the yaml output is sorted by key order (http://www.dzone.com/snippets/generating-yaml-hashes-sorted) but is this expected behaviour? Is there a better way to solve this problem?

[Andrew Beresford]

I've ended up separating the template into an external file and then doing something horrible;

out=scope.to_hash.reject { |k,v| k.to_s =~ /(uptime.*|timestamp|.*free|macaddress.*|ipaddress)/ }.to_yaml.split "\n"

header = out.shift

header = header+"\n"

sorted = out.sort

sorted_string = sorted.join "\n"

header << sorted_string

This only works because the structure of the facts.yaml content is very simple, and I'd much rather replace it with something more elegant.

I was originally trying to override the Hash to_yaml method to output the keys in alphabetical order, but I ended up fighting with it too much and gave up as I had other more important stuff to work on. 

Andrew

[Konrad Scherer]

On 12/05/2012 10:22 AM, Andrew Beresford wrote:
> I've ended up separating the template into an external file and then doing
> something horrible;
>
> out=scope.to_hash.reject { |k,v| k.to_s =~
> /(uptime.*|timestamp|.*free|macaddress.*|ipaddress)/ }.to_yaml.split "\n"
> header = out.shift
> header = header+"\n"
> sorted = out.sort
> sorted_string = sorted.join "\n"
> header << sorted_string
>
> This only works because the structure of the facts.yaml content is very simple,
> and I'd much rather replace it with something more elegant.
>
> I was originally trying to override the Hash to_yaml method to output the keys
> in alphabetical order, but I ended up fighting with it too much and gave up as I
> had other more important stuff to work on.

I had the same problem and tried an equally ugly hack which worked until the
yaml started containing perfectly legal yaml anchors and aliases (&id001 and
*id001)[1]. My current solution is:

cron {
'generate_facts':
command => '/usr/bin/facter --puppet --yaml >
/etc/mcollective/facter.yaml 2> /dev/null',
minute => '0';
}

This does miss the puppet variables in the current scope (move to custom fact?)
and potentially quickly changing facts (handled with facter_dot_d?). But this
works for my needs. If anyone has a better idea I would be very interested.

[1]: http://yaml.org/spec/1.2/spec.html#id2760395

--
Konrad Scherer, Sr. Engineer, Linux Products Group, Wind River
direct 613-963-1342 fax 613-592-2283

[Jakov Sosic]

On 12/03/2012 11:39 AM, Andrew Beresford wrote:
> I have set up puppet to create a facts.yaml file for mcollective using
> the following line:

There was another thread open few days ago, and suggested solution was:

content => inline_template('<%= Hash[scope.to_hash.reject { |k,v|
k.to_s =~ /(uptime|timestamp|memory|free|swap)/ }.sort].to_yaml %>'),


This works for me (TM) :)