I create instances in Compute Engine and depending on which system I choose, I get different messages when I try to connect to cloud sql. All settings are the same for both machines and the zone.
On CONTAINER-OPTIMIZED OS, the command "nc -vz XXX 5432" running on host (not in docker) returns:
XXX: inverse host lookup failed:
(UNKNOWN) [XXX] 5432 (postgresql): No route to host
On debian linux it's ok
XXX: inverse host lookup failed: Unknown host
(UNKNOWN) [XXX] 5432 (postgresql) open
I tried to change iptables but after allowing everything, it's still the same message.
EDIT
Problem reason:
Private address cloud sql is 172.17.2xx.x, docker generate also private network on os with address 172.17.xxx.x and mask /16, so when i try connect i cant because system use docker network.
What is the best solution without changing the os configuration?
I created new network in cloud and now cloud sql have ip from other unconflicted pool.