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Currently, Exograph supports one instance of Postgres as a database. You can configure the module using a few environment variables.

  • EXO_POSTGRES_URL - The URL of the Postgres database. The URL must be in the postgres://<username>:<password>@<host>:<port>/<database>?<connection-config-key-value> format. If the username is not specified, the EXO_POSTGRES_USER env must be set. The <password> defaults to an empty string unless the EXO_POSTGRES_PASSWORD environment variable is set. The <port> defaults to 5432.
  • EXO_POSTGRES_USER - The username of the Postgres database. This is only used if the username is not specified in the URL.
  • EXO_POSTGRES_PASSWORD - The password of the Postgres database. This is only used if the password is not specified in the URL.

Besides these environment variables, you can also configure connection pooling using the following environment variables:

  • EXO_CONNECTION_POOL_SIZE - The maximum number of connections in the pool. Defaults to 10.
  • EXO_CHECK_CONNECTION_ON_STARTUP - Whether to check the connection on startup. Defaults to true. This ensures that the connection is valid on startup. The connection will be checked on the first query if set to false.

You may use query parameters in the Postgres URL to configure SSL. For example, to set the verification mode to verify-full and specify the root certificate, you would use a URL such as postgres://...?sslmode=verify-full&sslrootcert=/path/to/root/cert.pem. Exograph supports the following query parameters:

  • ssl - Whether to use SSL. This parameter is a quick way to specify SSL mode. If it is true, it has the same effect as setting sslmode to verify-full.
  • sslmode - The SSL mode. The possible values are verify-full, verify-ca, require, prefer, allow, and disable. The default is prefer, where SSL will be used if the server supports it.
  • sslrootcert - The path to the root certificate (typically offered to be downloaded by the Postgres server provider). This is only used if the sslmode is not set to disable.