[chef] Re: Re: Using Tags for Knife Attributes

[Daniel DeLeo < >]

On Saturday, July 26, 2014 at 3:54 AM, Sheppy Reno wrote:

> Wow, after many hours of trying 'Tags' I accidentally type it all lower
> case and it magically works, but apparently only when the tag contains
> only the public IP. So my follow up to this is how do I pull just one
> of the tags when there are multiple?
>  
> Thanks again,
> Sheppy


Tags are meant to be an Array of strings. There isn’t really an easy way to 
specify a path through a nested data structure that handles Arrays like you 
want. For example, suppose you add a new tag to some nodes, and for some 
reason the order isn’t the same on all nodes. Then you would have  

node1[‘tags’] == [“1.2.3.4”, “my_new_tag”]
node2[‘tags’] == [“my_new_tag”, “2.3.4.5”]

Since you can only refer to array elements by position, there’s no way to 
pick a specific tag except by iterating over the elements and inspecting them.

I’d recommend making a custom attribute that’s a Hash instead. In your recipe 
code, do:

node.set[“external_ip”] = “1.2.3.4”

And with knife, use

knife ssh QUERY -a external_ip

HTH

--  
Daniel DeLeo