Problem connecting to postgresql hosted in docker - postgresql

Question

I have below error connecting to postgresql database hosted in docker.
myapp_Container | WARNING - ConnectionBus: Database connections: 0 active, 0 idle.
myapp_Container | ERROR - ConnectionBus: Opening JDBC connection to Some(db:54325) failed with SQLState: 08001 Error code: 0 Message: The connection attempt failed., giving up...(4/4)
myapp_Container | WARNING - ConnectionBus: Cannot create database connection.
I have two docker-compose files as below
APP Docker-Compose file
version: "3"
services:
app:
image: myapp
container_name: myapp_Container
ports:
- "8081:8081"
network_mode: postgres_net
environment:
- ADMIN_PASSWORD=Password1!
- DATABASE_ENDPOINT=postgres://user:passwd#db:54325/mydb
external_links:
- db:localpostgres_1
DB Docker-Compose file
version: "3"
services:
postgres:
image: postgres
container_name: localpostgres_1
restart: always
environment:
- POSTGRES_USER=user
- POSTGRES_PASSWORD=passwd
- TZ=Europe/Amsterdam
ports:
- 54325:5432
networks:
- postgres_net
networks:
postgres_net:
external: true
I created postgres_net via docker network create -d bridge postgres_net
Why am I doing this? I want to create apps with same docker-compose structure without creating a postgresql db for each, if I put them together like below it will work.
version: "3"
services:
app:
image: myapp
container_name: myapp_Container
ports:
- "8081:8081"
environment:
- ADMIN_PASSWORD=Password1!
- DATABASE_ENDPOINT=postgres://user:passwd#db/mydb
links:
- db
db:
image: postgres
container_name: postgres_x
ports:
- "54320:5432"
environment:
- TZ=Europe/Amsterdam
- POSTGRES_USER=user
- POSTGRES_PASSWORD=passwd
restart: always
I can connect to the Db via pgadmin, but can't understand why myapp cannot connect, please help
pg_hba.conf
local all all trust
# IPv4 local connections:
host all all 127.0.0.1/32 trust
# IPv6 local connections:
host all all ::1/128 trust
# Allow replication connections from localhost, by a user with the
# replication privilege.
local replication all trust
host replication all 127.0.0.1/32 trust
host replication all ::1/128 trust
host all all all md5

Answer 1

You have not properly defined network in First compose file(App compose). You have specified postgres_net as network_mode: postgres_net which is invalid. You need to specify it properly like in the second compose file.
Corrected compose file will be:
APP Docker-Compose
version: "3"
services:
app:
image: myapp
container_name: myapp_Container
ports:
- "8081:8081"
environment:
- ADMIN_PASSWORD=Password1!
- DATABASE_ENDPOINT=postgres://user:passwd#db:54325/mydb
networks: # declare network here
- postgres_net
networks: #define network
postgres_net:
external: true
DB Docker-Compose
version: "3"
services:
postgres:
image: postgres
container_name: localpostgres_1
restart: always
environment:
- POSTGRES_USER=user
- POSTGRES_PASSWORD=passwd
- TZ=Europe/Amsterdam
ports:
- 54325:5432
networks:
- postgres_net
networks:
postgres_net:
external: true

Answer 2

this config worked perfectly
app docker-compose file
version: "3"
services:
mendix:
image: myapp
container_name: myapp_Container
ports:
- "8081:8081"
network_mode: postgres_net
environment:
- ADMIN_PASSWORD=Password1!
- DATABASE_ENDPOINT=postgres://user:passwd#localpostgres_1/myapp
external_links:
- localpostgres_1
networks:
postgres_net:
external: true
db docker-compose
version: "3"
services:
postgres:
image: postgres
container_name: localpostgres_1
restart: always
environment:
- POSTGRES_USER=user
- POSTGRES_PASSWORD=passwd
- TZ=Europe/Amsterdam
ports:
- 54325:5432
networks:
- postgres_net
networks:
postgres_net:
external: true
as probably people may know, one may run the docker-compose files in a different folder per application, because docker-compose cares about the path and overwrites the last container you created in a given folder.