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Multiplayer lobby

  • RAM requirements: 512 MB (may increase over time if lobby gets more active players)
  • CPU requirements: 1 core (preferrably dedicated to ensure low latency)
  • SSD requirements: up to 4 Gb (depending on log and database size over time)

Exposed to public as:

  • lobby.vcmi.eu:3031 - user login
  • beholder.vcmi.eu:3031 - old domain name for logins

  • api.vcmi.eu - public API access (behind Cloudflare)

  • Start: cd /home/lobby && nohup sudo -u lobby /usr/games/vcmilobby &

  • Stop: killall -9 vcmilobby
  • Examine database (can be done live): sqlite3 /home/lobby/.local/share/vcmi/vcmiLobby.db
  • Examine log file: tail -n 100 /home/lobby/cache/vcmi/VCMI_Lobby_log.txt

Setup

Preparation:

  • Generate .deb package with lobby binaries. Currently we have "Build VCMI Lobby" job in CI that does this. Produced .deb file needs to be uploaded to server
  • Create dump of existing SQL database: sqlite3 /home/lobby/local/share/vcmi/vcmiLobby.db ".backup 'vcmiLobbyBak.db'". Optionally it can be compressed via gzip vcmiLobbyBak.db
  • Copy database dump on new server, and decompress it if needed via gunzip vcmiLobbyBak.db.gz

Once preparation is done, run the following commands:

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apt install nginx sqlite3 sqlite3-tools
apt install ./vcmi-lobby.deb #NOTE: name may be different

useradd -m lobby
sudo -u lobby mkdir -p /home/lobby/.local/share/vcmi/

# to create new DB
sudo -u lobby sqlite3 ~/.local/share/vcmi/vcmiLobby.db </usr/share/vcmi/config/lobby.sql

# to restore existing DB
mv vcmiLobbyBak.db /home/lobby/.local/share/vcmi/vcmiLobby.db 
chown lobby:lobby /home/lobby/.local/share/vcmi/vcmiLobby.db 

# Start lobby
cd /home/lobby && nohup sudo -u lobby /usr/games/vcmilobby &

Upgrade

  • Generate and upload new .deb package
  • Shut down old version of lobby: killall -9 vcmilobby
  • Install new .deb package via apt install ./vcmi-lobby.deb
  • Generate empty database with new schema: sqlite3 "schema.db" < "/usr/share/vcmi/config/lobby.sql"
  • Compare old and new databases sqldiff --schema vcmiLobby.db schema.db > upgrade.sql
  • Open upgrade script and edit it if necessary: nano upgrade.sql
  • Make sure that you have database backup: sqlite3 /home/lobby/local/share/vcmi/vcmiLobby.db ".backup 'vcmiLobbyBak.db"
  • Upgrade database to new schema: sqlite3 vcmiLobby.db < upgrade.sql
  • Re-run compare to verify that databases are now the same: sqldiff --schema vcmiLobby.db schema.db > upgrade.sql
  • Start new lobby server cd /home/lobby && nohup sudo -u lobby /usr/games/vcmilobby &

Troubleshooting

  • Lobby crashes on start due to boost::filesystem::status: Permission denied [system:13]: "config". Solution: cd /home/lobby (or any other directory writeable by lobby user)
  • Lobby shut downs after logout from server: ensure that vcmilobby was started via nohup