TL;DR;

start gremlin with persistance

Graph will be saved in the volume folder when you will stop the container.

mkdir volume
docker run \
	-d \
	--rm \
	-p 8182:8182 \
	-v $PWD/volume:/opt/gremlin-server/volume \
	--name gremlin-server \
	--init \
	brugnara/gremlin-server

Stop the container

The stop will trigger the save on disk

docker stop gremlin-server

Build from repo, then start as a daemon

Check start.sh if you don't need daemon.

docker build -t brugnara/gremlin-server:3.3.3 . 
bash daemon.sh 
docker logs -f gremlin-server

Persistance

Gremlin saves on disk, in the volume folder, the graph, just before a shutdown:

docker stop gremlin-server
ls -lah volume/
total 12K
drwxr-xr-x 2 root root 4,0K mag 21 12:05 .
drwxrwxr-x 4 vrut vrut 4,0K mag 21 12:08 ..
-rw-r--r-- 1 root root   90 mag 21 12:05 graph.json