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

[Dan-Joe Lopez < >]

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:  " target="_parent">Noah Kantrowitz
Sent: ‎Monday‎, ‎July‎ ‎6‎, ‎2015 ‎5‎:‎03‎ ‎PM
To:  " target="_parent">

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