Issues connecting to AWS RDS PostgreSQL with enforced SSL

[akira28]

I'm trying to figure out the correct configuration to be able to connect to an AWS RDS PosgreSQL instance with enforced SSL.
Right now I'm getting:

[postgres] FATAL: no pg_hba.conf entry for host "XX.XXX.XX.XXX", user "XXXX", database "kong", SSL off, client: 172.17.0.1, server: kong

I tried fiddling with the ssl config, trying to set lua_ssl_trusted_certificate with the rds-combined-ca-bundle.pem provided by AWS. I also tried changing lua_ssl_verify_depth to 1, 2 and 10, pg_ssl = on, pg_ssl = off, pg_ssl_verify = on, pg_ssl_verify = off with various combinations, without success.

Trying to connect with the psql command line works as expected:

psql -h xxxxx.us-east-1.rds.amazonaws.com -p 5432 "dbname=kong user=xxxx sslrootcert=/var/certs/rds-combined-ca-bundle.pem sslmode=verify-full"

this gets me to the password prompt and once logged in it works as expected.

Any suggestions?