is log_driver must even for "json-file"?

Hi,

I started a container using ansible without specifying log-driver as “json-file” is the default one, but I added below log_options:

log_options:
max-size: “10m”
max-file: “2”

Ansible version: 2.2.1.0

What I expected?
Container should run with these log_options as json-file is default

What I found?
docker inspect showed no log_options were configred.
“LogConfig”: {
“Type”: “json-file”,
“Config”: {}
},

Upon specifying “json-file” as the log_driver, I was able to see log_options.
Playbook:
log_driver: “json-file”
log_options:
max-size: “10m”
max-file: “2”

docker inspect:
“LogConfig”: {
“Type”: “json-file”,
“Config”: {
“max-file”: “2”,
“max-size”: “10m”
}

Doesnt Ansible assumes default log_driver like docker does?

Regards,
Kavya K