Opscode Chef - List/count EC2 instance AZ placement for your nodes with knife

count_ec2_instance_placement.sh

#!/bin/sh

# Prints the number of nodes you have in each EC2 AZ
knife exec -E 'nodes.transform("*:*") {|n| puts "#{n.ec2.placement_availability_zone}"}' | awk '
{
for (i=1;i<=NF;i++)
count[$i]++
}
END {
for (i in count)
print count[i], i
}' $* | sort -r

list_ec2_instance_placement.sh

#!/bin/sh

# Lists your nodes and their EC2 AZ placement
knife exec -E 'nodes.transform("*:*") {|n| puts "#{n.name}: #{n.ec2.placement_availability_zone}"}' | sort

# Note that you can get the same data with the knife search command below, but using knife exec lets you control the output format
# $ knife search node '*:*' -a ec2.placement_availability_zone