I created a mongo dump with commands (as suggested in this answer)
docker exec -it mongodb bash
mongodump --host $cluster --ssl --username $username --authenticationDatabase admin --db $dbname --gzip --archive > dumpname.gz
Now when I'm trying to restore the dump with
docker exec mongodb bash -c 'mongorestore --gzip --archive=dumpname.gz'
I get
Failed: gzip: invalid header
It seems like there is some bug with using redirection (>). So when I changed the first command to not use it, mongorestore started to work:
mongodump --host $cluster --ssl --username $username --authenticationDatabase admin --db $dbname --gzip --archive=dumpname.gz
Some similar problems could be found here