$ git clone https://github.com/DmitryZagr/guacamole-docker-compose.git
$ cd guacamole-docker-compose
$ mkdir init
$ cd init
$ docker run --rm guacamole/guacamole:1.5.5 /opt/guacamole/bin/initdb.sh --postgres > initdb.sql
$ cd ..
docker-compose up -d
Then go to http://DOCKER_HOST:8080/guacamole/
Log in as user: guacadmin
and password: guacadmin
.