So it’s not as clearly documented as it could be, but it is a simple fix:
Visit Docker > Preferences > Daemon > Advanced
in the toolbar and add the line
"ip" : "127.0.0.1",
to the start of the configuration file, i.e. it will look like
{
"ip" : "127.0.0.1",
"experimental" : false
}
Restart and then the default (i.e. when you don’t define it) host for published ports will be 127.0.0.1
.