I run postgres on several Windows servers (Windows Server 2012 R2, Windows Server 2016) as a part of a commercial framework running on an Apache tomcat webserver. The local connection worked fine. However, I want the same postgres server to be accessible for another framework (Cakephp) on another server (Red Hat Enterprise Linux) on the same server farm. This used to work until I upgraded to postgres 9. Now I had to upgrade to postgres 10. No matter what I tried, I failed.
Here is what I did to solve the problem:
Find your local postgres configuration files. They are usually in the same directory as the postgres tablespace, in my case:
d:\PG10Data\postgresql.conf.
This file has to contain the following lines:
# - Connection Settings:
listen_addresses = '*' # what IP addresses/interfaces to listen on
port = 5432
The next file to be modified is the pg_hba.conf (hba = host based access):
# TYPE DATABASE USER ADDRESS METHOD
# some sample entries:
# this will open UP ALL REMOTE IPv4 connections, do not open up permanently
host all all 0.0.0.0/0 md5
# only 1 database for 1 user from 1 IPv4 address:
host yourdatabasename yourusername 10.15.17.13/32 md5
# don not forget the "/32", otherwise the postgres server will not start up!
After editing these files, restart the postgres server.
You can run
netstat -a -n | findstr 5432
to see if the postgres listener is running.
You can also run the following to test connectivity from the Windows command prompt:
psql -Uyourusername -dyourdatabasename -p5432 -hlocalhost
This should work at any time. The next level will be to use your computer's local IPv4 address. This you can find out with
ipconfig
This will tell you your local IPv4 address. Use this in the following command:
psql -Uyourusername -dyourdatabasename -p5432 -hyourlocalip
My problem was, this command failed. Since I ran it directly on my server, it could not be the local Windows firewall.
The solution:
There is a 2nd configuration file:
d:\PG10Data\postgresql.auto.conf
The file starts ominously with the following 2 lines:
# Do not edit this file manually!
# It will be overwritten by the ALTER SYSTEM command
And it ends:
listen_addresses = 'localhost'
I tried the ALTER SYSTEM command when I was logged on locally as postgres via psql, but no success.
In the end I turned cheeky and changed the entry in d:\PG10Data\postgresql.auto.conf to;
listen_addresses = '*'
Bingo! After a postgres restart, remote access worked like a charm on both Windows servers.
N. B. Don't forget the Windows Firewall: Open port 5432 for remote access. Also check there are no firewalls in the network the block access to port 5432 from your remote client.
It would be nice if someone were able to tell me how I should have changed the parameter without editing the postgresql.auto.conf, but at least both of my framesworks - both on the local and the remote server - are working.