Using Docker to launch web app, can't connect to Postgresql DB?
Why I can NOT connect to localhost:5432?
Cat your container's /etc/hosts
$ sudo docker exec -it [container] cat /etc/hosts
For docker networks is bridge
by default, the localhost
inside points to container itself(Docker default bridge network).Then you don't have 5432
listening in your container:
$ sudo docker exec [container] nc -v -z localhost 5432
Solution 1. If you wanna hardcode the "localhost:5432" inside your config xml, the easiest way is creating your container with the option "--net=host":
$ sudo docker run --net=host -it ...
Solution 2. Change the
localhost
of your docker host ip inside the container- Get your docker host ip:
$ sudo docker inspect -f '{{ .NetworkSettings.Gateway }}' 192.168.5.1
- Enter your container:
$ sudo docker exec -it [container] /bin/bash
- Edit the file
/etc/hosts
to point the localhost to docker host ip:$ sudo vim /etc/hosts192.168.5.1 localhost
Solution 3. Modify your db config file to use an alias instead of localhost
:
connectionURL="jdbc:postgresql://DB_ALIAS/admin?stringtype=unspecified"
Then add the DB_ALIAS
to the container's hosts :$ sudo docker run --add-host DB_ALIAS:192.168.5.1 -it [image] ...
If you are using docker-compose together with postgres image, than you can reuse service name as IP inside jdbc connection (here: app-db)
web: build: ./web ports: - "8080:8080" links: - app-db environment: - MYAPP_JDBC_URL=jdbc:postgresql://app-db:5432/somedb - MYAPP_JDBC_USER=someuser - MYAPP_JDBC_PASS=pass app-db: image: postgres:9.6 environment: - POSTGRES_USER=someuser - POSTGRES_PASSWORD=pass - POSTGRES_DB=somedb expose: - 5432 volumes_from: - app-db-data app-db-data: image: cogniteev/echo command: echo 'Data Container for PostgreSQL' volumes: - /opt/postgresdata/:/var/lib/postgresql/data
I was getting the same error but this simple solution works perfect for me.sudo docker run -d --net="host" -it <IMAGE>
Now I can run my app https://x.x.x.x:pppp/../..
and everything works fine. I hope this helps