如何将Spring Boot Web App连接到Postgresql数据库

Question

I'm working on a Spring boot project and i tried to connect my server to a postgresql database. When i run the program with my IDE (on my windows OS) it's working but when i make a jar file and run it on my ubuntu server virtual machine which host my DB it doesn't work.

org.postgresql.util.PSQLException: Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.

I've check my firewall rules but still no sucess.

Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

I make some research and I heard about the configuration files of postgresql to modify but it still doesn't work and i have no idea where the issue comes.

Below the lines that i've modified on postgresql.conf:

listen_addresses = '*'          # what IP address(es) to listen on;
ssl = on

and for the pg_hba.conf:

local   all             postgres                                peer
local   all             kapitax                                trust
# TYPE  DATABASE        USER            ADDRESS                 METHOD
#host   all             kapitax        *                       password
#host   all             all             0.0.0.0/0               md5
# "local" is for Unix domain socket connections only
local   all             all             *                       trust
# IPv4 local connections:
host    all             all             *                       password
# IPv6 local connections:
host    all             all             ::1/128                 password
# Allow replication connections from localhost, by a user with the
# replication privilege.
local   replication     all                                     peer
host    replication     all             *                       md5
host    replication     all             ::1/128                 md5

The issue can comes from the applcation.properties code ?

spring.datasource.url= jdbc:postgresql://localhost:5432/kapitax
spring.datasource.username=kapitax
spring.datasource.password=kapitax
spring.jpa.hibernate.ddl-auto=create-drop
server.port=8090

Answer 1

The line

#host   all             all             0.0.0.0/0               md5

should be enabled like:

host   all             all             0.0.0.0/0               md5

With 0.0.0.0/0 you will listen for all IPv4 addresses. After you change this configuration make sure to reload your server settings or restart the database server. A more detailed explanation can be found in the following answer: How to configure PostgreSQL to accept all incoming connections