This buildpack sets up the PgBouncer exporter to expose Metrics of PgBouncer running in the Heroku Dyno alongside application code.
In your Procfile, start pgbouncer_exporter with a configuration then your application.
bin/start-pgbouncer-exporter YOUR_PROC_CMD
Add environment variable PGBOUNCER_EXPORTER_CONNECTION_STRING with connection string to PgBouncer:
PGBOUNCER_EXPORTER_CONNECTION_STRING = postgresql://pgbouncer@:6000/pgbouncer?host=/tmp&sslmode=disable&connect_timeout=30
As it's recommended in the PGBouncer Exporter docs, a configuration change to pgbouncer to ignore a PostgreSQL driver connection parameter is needed. Add this variable to Config vars of your application:
PGBOUNCER_IGNORE_STARTUP_PARAMETERS = extra_float_digits