How to link Jenkins and Postgres in Docker?

Question

PostgreSQL

Good afternoon.
Decided to play around with docker and CI. Installed docker on Ubuntu 16.04, downloaded docker-ui, postgres and jenkins images. My current container startup script is:
docker run --name myUiDocker -p 9000:9000 --privileged -v /var/run/docker.sock:/var/run/docker.sock -d uifd/ui-for-docker
docker run --name myPostgres -p 5432:5432 -e POSTGRES_PASSWORD=password -d postgres
docker run --name myJankins -p 9001:8080 -p 50000:50000 --link myPostgres:postgres -v /home/docker/jenkins_home:/var /jenkins_home -d jenkins
I configured Jenkins to take a spring-boot java application from git and run it. On startup I get this kind of exception: "Unable to build Hibernate SessionFactory: Unable to open JDBC Connection for DDL execution: Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections. Connection refused (Connection refused) -> [Help 1]".
With pgAdmin, I connect to the database normally at 127.0.0.1:5432, if I just manually launch the application from the Jenkins working directory (java -jar aaa.jar), then everything is fine too, the application sees the database. So I'm setting up Docker incorrectly.
Please tell me what am I doing wrong?
Thank you.

Answer 1

I have not worked with docker for a long time, but it seems that you still need to specify EXPOSE port
difference-between-expose-and-publish-in-docker

Answer 2

try connecting in Jenkins not to localhost, but to myPostgres:5432

Answer 3

go to the jenkins container from there try telnet to myPostgres 5432