# Parameter

> customize FerretDB with 9-parameter
---

There are 9 parameters in the [`FERRET`](/docs/ferret) module.

| Parameter             |  Type  | Level | Comment                                      |
|-----------------------|:------:|:-----:|----------------------------------------------|
| `mongo_seq`           |  int   |   I   | mongo instance identifier, REQUIRED          |
| `mongo_cluster`       | string |   C   | mongo cluster name, MONGO by default         |
| `mongo_pgurl`         | pgurl  |  C/I  | underlying postgres URL for ferretdb         |
| `mongo_ssl_enabled`   |  bool  |   C   | mongo/ferretdb ssl enabled, false by default |
| `mongo_listen`        |   ip   |   C   | mongo listen address, empty for all addr     |
| `mongo_port`          |  port  |   C   | mongo service port, 27017 by default         |
| `mongo_ssl_port`      |  port  |   C   | mongo tls listen port, 27018 by default      |
| `mongo_exporter_port` |  port  |   C   | mongo exporter port, 9216 by default         |
| `mongo_extra_vars`    | string |   C   | extra environment variables for MONGO server |


------

## Defaults

The default parameters are defined in [`roles/ferret/defaults/main.yml`](https://github.com/pgsty/pigsty/blob/v3.7.0/roles/ferret/defaults/main.yml)

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

------

## `mongo_cluster`

name: `mongo_cluster`, type: `string`, level: `C`

mongo cluster name, required identity parameter.

default value is `MONGO`, but you should define it explicitly for production use.

Comply with regexp `[a-z][a-z0-9-]*`, it is recommended to use descriptive names and start with `mongo-`

------

## `mongo_seq`

name: `mongo_seq`, type: `int`, level: `I`

mongo instance sequence number, unique integer among mongo cluster is required

You have to explicitly define the sequence number for each mongo instance. integer start from 0 or 1.

------

## `mongo_pgurl`

name: `mongo_pgurl`, type: `pgurl`, level: `C/I`

underlying postgres URL for ferretdb connection.

no default value, you have to define it explicitly. This is the PostgreSQL database URL that FerretDB will use as its backend storage.

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

------

## `mongo_ssl_enabled`

name: `mongo_ssl_enabled`, type: `bool`, level: `C`

mongo/ferretdb ssl enabled flag.

default value is `false`. Set to `true` to enable SSL/TLS encryption for mongo connections.

------

## `mongo_listen`

name: `mongo_listen`, type: `ip`, level: `C`

mongo listen address for binding.

default value is empty string `''`, which means listen on all available addresses. You can specify a specific IP address to bind to.

------

## `mongo_port`

name: `mongo_port`, type: `port`, level: `C`

mongo service port for client connections.

default value is `27017`, which is the standard MongoDB port. Change this if you need to avoid port conflicts.

------

## `mongo_ssl_port`

name: `mongo_ssl_port`, type: `port`, level: `C`

mongo tls listen port for encrypted connections.

default value is `27018`. This port is used when SSL/TLS is enabled for secure connections.

------

## `mongo_exporter_port`

name: `mongo_exporter_port`, type: `port`, level: `C`

mongo exporter port for metrics collection.

default value is `9216`. This port is used by the monitoring exporter to expose metrics for Prometheus.

------

## `mongo_extra_vars`

name: `mongo_extra_vars`, type: `string`, level: `C`

extra environment variables for MONGO server.

default value is empty string `''`. You can specify additional environment variables that will be passed to the FerretDB process.