Nginx Proxy Manager fails to connect to remote MariaDB: ignores environment variables and initializes SQLite instead

[evsukator]

Hello my friends :-)
Problem:
When running Nginx Proxy Manager
in Docker with environment variables pointing to a remote MariaDB (MySQL in LXC) instance (on a separate DMZ server), the container ignores the DB configuration and automatically initializes a local SQLite database (/data/database.sqlite). Logs consistently show Using Sqlite: /data/database.sqlite, and migrations are applied to SQLite rather than MySQL.
Configuration:

• Image: jc21/nginx-proxy-manager:2.16.0
• Database: Remote MariaDB on a dedicated DMZ server
• Environment variables in docker-compose.yml: DB_HOST, DB_PORT, DB_USER, DB_PASSWORD, DB_NAME
• Network: Custom bridge
• Volumes: ./data:/data, ./letsencrypt:/etc/letsencrypt
  Observations:

1. Using DB_MYSQL_* variables (as in examples for local db service) does not work for external IPs, since NPM expects a Docker service name, not a real address.
2. Even with DB_* variables, the container still falls back to SQLite after full recreation (docker compose down/up).
3. Inside the container, variables are confirmed present: docker exec <container_name> env | grep -i DB_.
4. Connectivity from the host is verified (nc -vz <DB_HOST> <DB_PORT>), and DB grants are configured for the host IP (accounting for SNAT).
   Hypotheses:
   There may be a bug in the current image’s logic for processing DB_* environment variables.
   Or an explicit flag/variable is required to force the use of an external backend.
   Steps to reproduce:

Deploy docker-compose.yml with DB_HOST=<external_db_ip>, DB_PORT=<db_port>, etc.
Run docker compose up -d.
Check logs: docker logs --tail 100.
Expected: attempt to connect to MariaDB. Actual: Using Sqlite.
Environment:

Host OS: Debian trixie
Docker: official repository
Network architecture: DMZ with VLANs, routing via custom table, host-level SNAT

[charles-benedito]

hmm afaik there are no DB_HOST / DB_USER / DB_NAME vars at all, which is why u get Using Sqlite. the backend only looks at DB_MYSQL_HOST, DB_MYSQL_PORT, DB_MYSQL_USER, DB_MYSQL_PASSWORD and DB_MYSQL_NAME (or the DB_POSTGRES_* ones), and if host, user and name aren't all set it silently falls back to sqlite:

nginx-proxy-manager/backend/lib/config.js

Lines 45 to 57 in 1aca775

	const envMysqlHost = process.env.DB_MYSQL_HOST || null;
	const envMysqlUser = process.env.DB_MYSQL_USER || null;
	const envMysqlName = process.env.DB_MYSQL_NAME || null;
	const envMysqlSSL = toBool(process.env.DB_MYSQL_SSL);
	const envMysqlSSLRejectUnauthorized =
	process.env.DB_MYSQL_SSL_REJECT_UNAUTHORIZED === undefined
	? true
	: toBool(process.env.DB_MYSQL_SSL_REJECT_UNAUTHORIZED);
	const envMysqlSSLVerifyIdentity =
	process.env.DB_MYSQL_SSL_VERIFY_IDENTITY === undefined
	? true
	: toBool(process.env.DB_MYSQL_SSL_VERIFY_IDENTITY);
	if (envMysqlHost && envMysqlUser && envMysqlName) {

and DB_MYSQL_HOST doesn't need to be a compose service name, it's just handed to the mysql client as the host, so the ip or dns name of ur mariadb box is fine. the db in the docs example is only because that example runs the db container in the same compose file: https://nginxproxymanager.com/setup/#using-mysql-mariadb-database

if u saw a different error with the DB_MYSQL_* vars, that's connectivity or grants rather than a fallback, so post that log. lmk if that works

[charles-benedito]

sup @evsukator , evsukatordid switching to the DB_MYSQL_* vars get it talking to ur mariadb box? if it still falls back to sqlite or throws something different, paste the startup log and i'll have another look

[evsukator]

Good morning. Today I’ll try to find time to reproduce the error. The deadlines for current projects are looming (end of the month…)