def docker_ip(docker_host_string):
return docker_host_string.split('<STR_LIT::>')[<NUM_LIT:1>].split('<STR_LIT>')[<NUM_LIT:1>]<EOL>
returns the ip address of the docker daemon

params:
    string docker_host_string: URL of the docker daemon
returns:
    string: ip address of the docker host