Support for Default Postgres Params

[eberlep]

⚠️ Introduce default Postgres Params -> triggers rolling update of running databases

[eberlep]

Patroni:

 $ k exec -c postgres pgfits-defaultparams9365a4d-0  -- grep -E "tcp_keepalives_idle|tcp_keepalives_interval|ssl_min_protocol_version|ssl_prefer_server_ciphers|ssl_ciphers|log_file_mode" postgres.yml
        ssl_ciphers: ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384
        ssl_min_protocol_version: TLSv1.2
        ssl_prefer_server_ciphers: 'on'
        tcp_keepalives_idle: '200'
        tcp_keepalives_interval: '30'
    log_file_mode: '0600'

Postgres:

 $ k exec -c postgres pgfits-defaultparams9365a4d-0  -- grep -E "tcp_keepalives_idle|tcp_keepalives_interval|ssl_min_protocol_version|ssl_prefer_server_ciphers|ssl_ciphers|log_file_mode" /home/postgres/pgdata/pgroot/data/postgresql.conf
log_file_mode = '0600'
ssl_ciphers = 'ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384'
ssl_min_protocol_version = 'TLSv1.2'
ssl_prefer_server_ciphers = 'on'
tcp_keepalives_idle = '200'
tcp_keepalives_interval = '30'

Override (does not seem to affect the postgres.yml):

 $ k exec -c postgres pgfits-defaultparams9365a4d-0  -- patronictl show-config | grep tcp_keepalives_idle
    tcp_keepalives_idle: '234'

 $ k exec -c postgres pgfits-defaultparams9365a4d-0  -- grep -E "tcp_keepalives_idle" /home/postgres/pgdata/pgroot/data/postgresql.conf
tcp_keepalives_idle = '234'