ansible/examples/playbooks/conditionals_part2.yml

---
# this is a demo of conditional executions using 'when' statements, which can skip
# certain tasks on machines/platforms/etc where they do not apply.  

- hosts: all
  user: root

  vars:
     favcolor: "red"
     dog: "fido"
     cat: "whiskers"
     ssn: 8675309

# These are the types of when statemnets available
#     when_set: $variable_name
#     when_unset: $variable_name
#     when_str: $x == "test"
#     when_int: $y > 2
#     when_float: $z => 2.3
#
# when using 'when', take care to make sure any variables given are surrounded by spaces
# as an example, $z>3 will not do what you want, use "$z > 3"
#
# note, if you are doing comparisons to variables that are stored as hashes or lists,
# you will need to use the older 'only_if', which is more free form.  
# see conditionals_part_3.yml

  tasks:

     - name: "do this if my favcolor is blue, and my dog is named fido"
       action: shell /bin/false
       when_string: $favcolor == 'blue' and $dog == 'fido'

     - name: "do this if my favcolor is not blue, and my dog is named fido"
       action: shell /bin/true
       when_string: $favcolor != 'blue' and $dog == 'fido'

     - name: "do this if my SSN is over 9000"
       action: shell /bin/true
       when_integer: $ssn > 9000

     - name: "do this if I have one of these SSNs"
       action: shell /bin/true
       when_integer:  $ssn in [ 8675309, 8675310, 8675311 ]
     
     - name: "do this if a variable named hippo is NOT defined"
       action: shell /bin/true
       when_unset: $hippo

     - name: "do this if a variable named hippo is defined"
       action: shell /bin/true
       when_set: $hippo