Installation of Graylog docker
mongodump --db=graylog --out=/usr/share/graylog/data/graylogmongo.dump
Copy the config folder from /usr/share/graylog/data/config to restore inputs etc. Config dir listing:
graylog@e9533406c3a6:~$ ls /usr/share/graylog/data/config/ graylog.conf log4j2.xml node-id server.conf server.conf.dpkg-dist
Bare metal configuration is usually in /etc/graylog/server/
mongorestore --drop graylogmongo.dump
Above will drop the tables (collections) if they exist but only those in the backup.
Copy the backed up data back and restart graylog.
Also check the log4j2.xml file to make sure the paths are correct for loggin etc.