Useful Commands

docker <command> <double tab> to get possibilities

docker ps
    list containers

docker exec <container_name> <some_command>
    docker exec 97a87498eb3a_newstack_db_1 psql -U moodle -l
    docker exec 97a87498eb3a_newstack_db_1 ls

docker volume rm <container-name>

docker inspect <container-name>

Read logs from a docker container

docker logs <container-name-or-id>
docker logs moodle-docker-environment_webserver_1

Backup and restore database inside docker

docker exec -i {docker-container-name} pg_dump -U {user} -d {dbname} -w -Fc > /tmp/{dumpfile}.pgdump
docker cp /tmp/{dumpfile}.pgdump {docker-container-name}:/var/backups
docker exec {docker-container-name} pg_restore -O --role {user} -U {user} -d {dbname} /var/backups/{dumpfile}.pgdump
For e.g.
docker exec -i moodle-docker-environment_db_1 pg_dump -U moodle -d moodle400ucace -w -Fc > /tmp/moodle400ucace.pgdump
docker cp /tmp/moodle400ucace.pgdump moodle-docker-environment_db_1:/var/backups
docker exec moodle-docker-environment_db_1 pg_restore -O --role moodle -U moodle -d test /var/backups/moodle400ucace.pgdump