ansible and bigip_command

Try use ansible-playbook to test bigip_command, I got following error ERROR! 'bigip_command' is not a valid attribute for a Play

The error appears to have been in '/work/showver3.yaml': line 1, column 3, but may be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

• name: run show version on remote devices ^ here

===showver3.yaml=== - name: run show version on remote devices bigip_command: commands: show sys version server: "testlab.mydomain.local" password: "mypass" user: "admin" validate_certs: "no"