This is the bpel-g 5.3 (found here https://github.com/massfords/bpel-g) version running on Tomcat 8 with Java 8.
docker run -d -p 8080:8080 dvilaverde/bpel-g:latest
The bpel-g 'bpr' directory that contains the H2 database can be mounted with the volume at '/usr/local/tomcat/bpr', so to mount a directory on the host as the location for the H2 database, for example, you might use this command.
docker run -p 8080:8080 -v /path/to/data/dir:/usr/local/tomcat/bpr dvilaverde/bpel-g
The bpel-g application is exposed on port 8080 in the docker image and can be accessed at http://localhost:8080/bpel-g.