[chef] How ---- in a pain free method - to get the public ip address on ec2

[David Montgomery < >]

Hi,

I am having a very hard time getting the public ip address on ec2

1) the first recipes creates these resources

directory "/etc/chef/ohai/hints" do
  owner "root"
  group "root"
  recursive true
  action :create
end

file "/etc/chef/ohai/hints/ec2.json" do
  owner "root"
  group "root"
  action :create
end

2) In another recipe later down the line I get the ip address
if File.exists?("/etc/chef/ohai/hints/ec2.json")
    ipaddress = node['ec2']['public_ipv4']
    file "/tmp/public" do
      owner "root"
      group "root"
      mode "0755"
      content "#{ipaddress}"
      action :create
    end
 end

3) Wowee.....the file is not created.  Why does this happen?

4) And if I use this instead I get the below without checking for the existince of /etc/chef/ohai/hints/ec2.json

    ipaddress = node['ec2']['public_ipv4']
    file "/tmp/public" do
      owner "root"
      group "root"
      mode "0755"
      content "#{ipaddress}"
      action :create
    end

================================================================================
Recipe Compile Error in /var/chef/cache/cookbooks/cloudera/recipes/hostname.rb
================================================================================

NoMethodError
-------------
undefined method `[]' for nil:NilClass

Cookbook Trace:
---------------
  /var/chef/cache/cookbooks/cloudera/recipes/hostname.rb:17:in `from_file'

Relevant File Content:
----------------------
/var/chef/cache/cookbooks/cloudera/recipes/hostname.rb:

 

 17>>     ipaddress = node['ec2']['public_ipv4']
 18:      file "/tmp/public" do
 19:        owner "root"
 20:        group "root"
 21:        mode "0755"
 22:        content "#{ipaddress}"
 23:        action :create
 24:      end


[2014-08-13T01:51:21+00:00] ERROR: Running exception handlers
[2014-08-13T01:51:21+00:00] ERROR: Creating JSON exception report
[2014-08-13T01:51:21+00:00] ERROR: Exception handlers complete