[chef] Programmatically discover IP address based on tag search

[Mark Nichols < >]

All - 

I have a pair of application nodes that need to use a pair of Memcached 
nodes. For simplicity sake I’ll call that application nodes app1 and app2, 
and the Memcached nodes mem1 and mem2.

I need to open the firewall on mem1 and mem2 to allow incoming access on port 
11211, therefore I want to programmatically discover the IP addresses of app1 
and app2. Since this same cookbook will be used on alpha and production nodes 
I also need to discover the current tier.

In the code below, the memcached_instance attribute contains the same value 
as one of the tags on app1 and app2, e.g., “sso"


# determine if we are an alpha or production node
if node.chef_environment == "ome-alpha"
  local_environment = "alpha"
else
  local_environment = "prod"
end

# get the list of nodes...
application_nodes = search(:node, 
"tags:#{node['memcached']['memcached_instance']} AND 
tags:#{local_environment}")

application_nodes.each do |application_node|

  firewall_rule "allow application node ips"  do
    source application_node['ipaddress']
    port node['memcached']['port'] 
    protocol :tcp 
    action :allow 
    notifies :enable, 'firewall[ufw]'
  end

end

All of this looks good but it doesn’t work. My guess is that the array 
structure returned by my search statement is more complex than I suspect or 
differently structured in someway. I’ve looked at the results of the same 
basic command via knife (which returns the results I expect) but I can’t get 
this working.

What am I missing?

Thanks,
Mark