Parameters

Parameter Overview

The FERRET parameter group is used for FerretDB deployment and configuration, including identity, underlying PostgreSQL connection, listen ports, and SSL settings.

Defaults

Default parameters are defined in roles/ferret/defaults/main.yml:

# mongo_cluster:        #CLUSTER  # mongo cluster name, required identity param
# mongo_seq: 0          #INSTANCE # mongo instance sequence, required identity param
# mongo_pgurl: 'postgres:///'     # mongo/ferretdb underlying postgresql url, required
mongo_ssl_enabled: false          # mongo/ferretdb ssl enabled, default false
mongo_listen: ''                  # mongo/ferretdb listen address, '' for all
mongo_port: 27017                 # mongo/ferretdb listen port, default 27017
mongo_ssl_port: 27018             # mongo/ferretdb tls listen port, default 27018
mongo_exporter_port: 9216         # mongo/ferretdb exporter port, default 9216
mongo_extra_vars: ''              # mongo/ferretdb extra environment variables

mongo_cluster

Parameter: mongo_cluster, Type: string, Level: C

mongo cluster name, a required identity parameter.

No default value—you must explicitly define it for production environments.

The cluster name must comply with the regex [a-z][a-z0-9-]*. Using descriptive names is recommended.

mongo_seq

Parameter: mongo_seq, Type: int, Level: I

mongo instance sequence number, a unique integer identifier within the cluster.

You must explicitly define the sequence number for each mongo instance. Integers start from 0 or 1.

mongo_pgurl

Parameter: mongo_pgurl, Type: pgurl, Level: C/I

PostgreSQL URL for FerretDB backend connection, a required parameter.

No default value—you must explicitly define it. This is the PostgreSQL database connection string that FerretDB will use as its backend storage.

Format: postgres://username:password@host:port/database

Notes:

• The user needs to be a PostgreSQL superuser
• The target database needs the documentdb extension installed
• Using a dedicated mongod user is recommended

mongo_ssl_enabled

Parameter: mongo_ssl_enabled, Type: bool, Level: C

Enable SSL/TLS encryption for FerretDB.

Default is false. Set to true to enable SSL/TLS encryption for mongo connections.

When enabled, FerretDB will:

• Generate and issue SSL certificates
• Listen for encrypted connections on mongo_ssl_port

mongo_listen

Parameter: mongo_listen, Type: ip, Level: C

Listen address for mongo binding.

Default is empty string '', meaning listen on all available addresses (0.0.0.0). You can specify a specific IP address to bind to.

mongo_port

Parameter: mongo_port, Type: port, Level: C

Service port for mongo client connections.

Default is 27017, which is the standard MongoDB port. Change this port if you need to avoid port conflicts or have security considerations.

mongo_ssl_port

Parameter: mongo_ssl_port, Type: port, Level: C

TLS listen port for mongo encrypted connections.

Default is 27018. When SSL/TLS is enabled via mongo_ssl_enabled, FerretDB will accept encrypted connections on this port.

mongo_exporter_port

Parameter: mongo_exporter_port, Type: port, Level: C

Exporter port for mongo metrics collection.

Default is 9216. This port is used by FerretDB’s built-in metrics exporter to expose monitoring metrics to Prometheus.

mongo_extra_vars

Parameter: mongo_extra_vars, Type: string, Level: C

Extra environment variables for FerretDB server.

Default is empty string ''. You can specify additional environment variables to pass to the FerretDB process in KEY=VALUE format, with multiple variables separated by spaces.

Example:

mongo_extra_vars: 'FERRETDB_LOG_LEVEL=debug FERRETDB_TELEMETRY=disable'