[chef] Re: Re: Using variables to define attributes?

[Dan-Joe Lopez < >]

I think I am starting to get it…, and yes, now I see the output as you suggested.  Are the attributes this case sensitive?  node[‘hostname'] returns allcaps.  does ruby have something like var.tolower()?

thanks,

Dan-Joe

Sent from Windows Mail

From:  " target="_parent">Noah Kantrowitz
Sent: ‎Monday‎, ‎July‎ ‎6‎, ‎2015 ‎5‎:‎46‎ ‎PM
To:  " target="_parent">

Above that error, you should still see the value of var. Confirm that is what you expect it to be. The error likely means one of the levels of keys doesn't exist. Ruby returns nil on accessing a key that doesn't exist, so figure out which key that is and you should be able to correct it.

--Noah

On Jul 6, 2015, at 5:42 PM, Dan-Joe Lopez < > wrote:

> I had a similar idea with the logging. The error I am getting seems to be a "compile” error though, so it doesn't show my 1st logging data…
>
>
>
> #DEBUG ATTRIBURE ACCESS
> var = node['hostname']
> Chef::Log.info var
> Chef::Log.info <<-EOH
> \n
> !!!!!!!!!!!!!!!!!!!!!!!!!!!DEBUG ec2-ATTRIBURE ACCESS!!!!!!!!!!!!!!!!!!!!!!!!!!!
> --ec2.instances.ec2-8a4b54410.tags.ec2:owner: #{node[ec2]['instances']['mo-8a4b54410']['tags'][ec2:owner']}
> --ec2:owner: #{node['ec2:owner']}
> --hostname: #{node['hostname']}
> --ec2.instances.[hostname].tags.ec2:owner: #{node[ec2]['instances'][var]['tags'][ec2:owner']}
> !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> \n
> EOH
>
> and the error that I get is:
>
>
> ================================================================================
> Recipe Compile Error in C:/ec2/repos/devops_automation/kxen_ga/chef/site-cookbooks/debug/recipes/default.rb
> ================================================================================
>
> NoMethodError
> -------------
> undefined method `[]' for nil:NilClass
>
> Cookbook Trace:
> ---------------
> C:/ec2/repos/devops_automation/kxen_ga/chef/site-cookbooks/debug/recipes/default.rb:10:in `from_file'
>
> Relevant File Content:
> ----------------------
> C:/ec2/repos/devops_automation/kxen_ga/chef/site-cookbooks/debug/recipes/default.rb:
>
> 3: Chef::Log.info var
> 4: Chef::Log.info <<-EOH
> 5: \n
> 6: !!!!!!!!!!!!!!!!!!!!!!!!!!!DEBUG ec2-ATTRIBURE ACCESS!!!!!!!!!!!!!!!!!!!!!!!!!!!
> 7: --ec2.instances.ec2-8a4b54410.tags.ec2:owner: #{node['ec2']['instances']['mo-8a4b54410']['tags']['ec2:owner']}
> 8: --ec2:owner: #{node['ec2:owner']}
> 9: --hostname: #{node['hostname']}
> 10>> --ec2.instances.[hostname].tags.ec2:owner: #{node['ec2']['instances'][var]['tags']['ec2:owner']}
> 11: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> 12: \n
> 13: EOH
>
> Does this help at all?
> ​
>
> Sent from Windows Mail
>
> From: Noah Kantrowitz
> Sent: ‎Monday‎, ‎July‎ ‎6‎, ‎2015 ‎5‎:‎30‎ ‎PM
> To:
>
> If var == 'myhappyhost', those two are equivalent. Most likely some intermediary value is not what you expect. Add some logging to your recipe code:
>
> var = node['hostname']
> Chef::Log.info("var = #{var.inspect}")
> node['ec2']['instances'][var]....
>
> Don't forget to add `-l info` to the client command line too so it will display the logging output.
>
> --Noah
>
>
> On Jul 6, 2015, at 5:19 PM, Dan-Joe Lopez < > wrote:
>
> > Thanks for the quick reply Noah.  Unfortunately I don’t have a solid answer to your question.  I am working within an infrastructure that I did not create.  I am not sure what information that I can share with you beyond the below that you might find helpful.
> >
> > As far as access to other instances information; we have collections of instances organized into projects.  Each project contains a bunch of attributes from all of its instances, so that any instance can see them.
> >
> > As far as the data not being stored correctly, would that still be a concern, given that manually calling the attribute works as expected when call like this:
> > node[‘ec2’][‘instances’][‘myhappyhost’][‘ip’]
> > but fails when using the a var in place of the actual hostname:
> > node[‘ec2’][‘instances’][var][‘ip’]
> > ?
> >
> > Thanks,
> > Dan-Joe Lopez
> > Sent from Windows Mail
> >
> > From: Noah Kantrowitz
> > Sent: ‎Monday‎, ‎July‎ ‎6‎, ‎2015 ‎5‎:‎03‎ ‎PM
> > To:
> >
> >
> > On Jul 6, 2015, at 4:53 PM, Dan-Joe Lopez < > wrote:
> >
> > > OHAI Chefs!
> > >
> > > I don’t know if this is even possible, but I am starting to feel like it is not ☹ Also, I am pretty green, so my advanced apologies if this is a silly question.
> > >
> > > I would like to call a specific attribute by using a variable, or another attribute.  I cannot find any documentation on the subject, and every method that I have tried has resulted in an error.
> > >
> > > So, I can call node[‘hostname’] and get the hostname; not a problem.
> > > But then let’s say I want to write something that calls an attribute in which the host name is one of the path components… e.g.
> > > node[‘ec2’][‘instances’][HOSTNAME][‘ip’]…
> > >
> > > if I manually type in the host name, no problem:
> > > node[‘ec2’][‘instances’][‘myhappyhost’][‘ip’]
> > > BOOM: 12.34.56.78
> > >
> > > but when I try any variation of:
> > > node[‘ec2’][‘instances’][node[‘hostname’]][‘ip’]
> > > or
> > > var = node[‘hostname’]
> > > node[‘ec2’][‘instances’][var][‘ip’]
> > > node[‘ec2’][‘instances’][“var”][‘ip’]
> > > node[‘ec2’][‘instances’][‘var’][‘ip’]
> > > node[‘ec2’][‘instances’].var[‘ip’]
> > > etc…
> > >
> > > nothing but errors ☹
> > >
> > > Am I missing a permutation of syntax here? Is there documentation that would have given me the answer? Is this even possible?
> > >
> > > Your suggestions and help are appreciated!
> >
> >
> > node['ec2']['instances'][var] is correct, however chances are you are not storing things correctly. How are you populating that node['ec2']['instances'] hash? Nodes cannot see the node attributes of other nodes by default, you need to use the search API or something else to get that data.
> >
> > --Noah