Using Docker to launch web app, can't connect to Postgresql DB?

Question

I received the following error when trying to write session data using Tomcat\'s PersistentManager to a Postgres DB running on my local machine:

SEVERE: A SQL e         


        

Answer 1

I had to expose port with -p 5432:5432:

docker run --name postgres -e POSTGRES_PASSWORD=secret -d -p 5432:5432 postgres