How to read the number of lines in a multiline variable in Ansible

Question

I pass a multiline variable dest_host from Jenkins to Ansible as below

ansible-playbook -i allmwhosts.hosts action.yml -e '{ dest_host: myhost1
myhost2 }' --tags validate

In ansible i wish to count the number of lines present in dest_host which in this case is 2.

I can think of command: "cat {{ dest_host }} | wc -l" register the output and then print as a solution. However, is these a better way to get this in Ansible rather than going for a unix command ?

Answer 1

That is what the | length filter is for

- debug:
    msg: '{{ dest_host | length }}'
  vars:
    dest_host: "alpha\nbeta\n"

although be forewarned that your -e does not do what you think it does (about the lines) because of yaml's scalar folding

ansible -e '{ bob:
  alpha
  beta
}' -m debug -a var=bob -c local -i localhost, localhost

emits "bob": "alpha beta"

but the | length can still help you by using | split | length