# note that Ansible facts and vars like ansible_os_family can be used
# directly in conditionals without double curly braces
tasks:
- name: "shut down Debian flavored systems"
command: /sbin/shutdown -t now
when: ansible_os_family == "Debian"
Example 2 - Using When Condition
# You can also use parentheses to group conditions:
tasks:
- name: "shut down CentOS 6 and Debian 7 systems"
command: /sbin/shutdown -t now
when: (ansible_distribution == "CentOS" and ansible_distribution_major_version == "6") or
(ansible_distribution == "Debian" and ansible_distribution_major_version == "7")
Example 3 - Using When Condition
# Multiple conditions that all need to be true (a logical �and�) can also be specified as a list:
tasks:
- name: "shut down CentOS 6 systems"
command: touch /opt/verizon.txt
when:
- ansible_distribution == "RedHat"
- ansible_distribution_major_version == "7.5"
Example 4 - Using When Condition
#If a required variable has not been set, you can skip or fail using Jinja2�s defined test. For example:
tasks:
- shell: echo "I've got '{{ foo }}' and am not afraid to use it!"
when: foo is defined
- fail: msg="Bailing out. this play requires 'bar'"
when: bar is undefined
Example 5 - Using When Condition
# Following is the simplest example of checking whether the value of a variable. We have created a variable test1 and checking if the value is �Hello World� using the when statement.
- hosts: all
vars:
test1: "Hello World"
tasks:
- name: Ansible when variable equals example
debug:
msg: "Equals"
when: test1 == "Hello World"
Example 6 - Using When Condition
# We can also set the reverse, i.e. if the variable is not equal to another value.
- hosts: all
vars:
test1: "Bye World"
tasks:
- name: Ansible when variable not equals example
debug:
msg: "Not Equals"
when: test1 != "Hello World"
Example 7 - Using When Conditio
# We can also make a conditional statement based on whether the variable contains a particular string.
- hosts: all
vars:
test1: "Bye World"
tasks:
- name: Ansible when variable contains string example example
debug:
msg: "Equals"
when: test1.find("World") != -1
Example 8 - Using When Condition
#If the variable value is registered from a shell command you may have to use stdout.find to check the content.
- hosts: all
tasks:
- shell: cat /etc/temp.txt
register: output
- name: Ansible when variable contains string example example
debug:
msg: "Equals"
when: output.stdout.find("World") != -1
Example 9 - Using When Condition
# We can also check if a variable is empty using similar manner.
- hosts: all
tasks:
- shell: cat /etc/temp.txt
register: output
- name: Ansible when variable is empty example
debug:
msg: "empty"
when: output.stdout == ""
Example 9 - Using When Condition
---
# 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
remote_user: root
vars:
favcolor: "red"
dog: "fido"
cat: "whiskers"
ssn: 8675309
tasks:
- name: "do this if my favcolor is blue, and my dog is named fido"
shell: /bin/false
when: favcolor == 'blue' and dog == 'fido'
- name: "do this if my favcolor is not blue, and my dog is named fido"
shell: /bin/true
when: favcolor != 'blue' and dog == 'fido'
- name: "do this if my SSN is over 9000"
shell: /bin/true
when: ssn > 9000
- name: "do this if I have one of these SSNs"
shell: /bin/true
when: ssn in [ 8675309, 8675310, 8675311 ]
- name: "do this if a variable named hippo is NOT defined"
shell: /bin/true
when: hippo is not defined
- name: "do this if a variable named hippo is defined"
shell: /bin/true
when: hippo is defined
