Configuration flags

FerretDB provides numerous configuration flags you can customize to suit your needs and environment. You can always see the complete list by using --help flag. To make user experience cloud native, every flag has its environment variable equivalent. There is no configuration file.

General​

Interfaces​

Backend handlers​

PostgreSQL​

PostgreSQL backend can be enabled by --handler=pg flag or FERRETDB_HANDLER=pg environment variable.

FerretDB uses pgx v5 library for connecting to PostgreSQL. Supported URL parameters are documented there:

• https://pkg.go.dev/github.com/jackc/pgx/v5/pgconn#ParseConfig
• https://pkg.go.dev/github.com/jackc/pgx/v5#ParseConfig
• https://pkg.go.dev/github.com/jackc/pgx/v5/pgxpool#ParseConfig

Additionally:

• pool_max_conns parameter is set to 50 if it is unset in the URL;
• application_name is always set to "FerretDB";
• timezone is always set to "UTC".

SQLite​

SQLite backend can be enabled by --handler=sqlite flag or FERRETDB_HANDLER=sqlite environment variable.

FerretDB uses modernc.org/sqlite library for accessing SQLite database files. Supported URL parameters are documented there:

• https://www.sqlite.org/uri.html
• https://pkg.go.dev/modernc.org/sqlite#Driver.Open
• https://www.sqlite.org/pragma.html

Additionally:

• _pragma=auto_vacuum(none) parameter is set if that PRAGMA is not present;
• _pragma=busy_timeout(10000) parameter is set if that PRAGMA is not present;
• _pragma=journal_mode(wal) parameter is set if that PRAGMA is not present.

One difference is that URI should point to the existing directory (with absolute or relative path), not to a single database file. That allows FerretDB to work with multiple databases.

In-memory SQLite databases are fully supported. In that case, the URI should still point to the existing directory (that will be unused). For example: file:./?mode=memory.

Miscellaneous​