Where's docker's daemon.json? (missing)

From docs:

The default location of the configuration file on Linux is /etc/docker/daemon.json

But I don't have it on my fresh docker installation:

# docker --versionDocker version 17.03.1-ce, build c6d412e# ls -la /etc/docker/total 12drwx------  2 root root 4096 Apr 28 17:58 .drwxr-xr-x 96 root root 4096 Apr 28 17:58 ..-rw-------  1 root root  244 Apr 28 17:58 key.json# lsb_release -cstrusty