Connecting to Postgresql in a docker container from outside

I have Postgresql on a server in a docker container. How can I connect to it from the outside, that is, from my local computer? What setting should I apply to allow that?

Solution 1:

You can run Postgres this way (map a port):

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

So now you have mapped the port 5432 of your container to port 5432 of your server. -p <host_port>:<container_port> .So now your postgres is accessible from your public-server-ip:5432

To test: Run the postgres database (command above)

docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                     NAMES
05b3a3471f6f        postgres            "/docker-entrypoint.s"   1 seconds ago       Up 1 seconds        0.0.0.0:5432->5432/tcp    some-postgres

Go inside your container and create a database:

docker exec -it 05b3a3471f6f bash
root@05b3a3471f6f:/# psql -U postgres
postgres-# CREATE DATABASE mytest;
postgres-# \q

Go to your localhost (where you have some tool or the psql client).

psql -h public-ip-server -p 5432 -U postgres

(password mysecretpassword)

postgres=# \l

                             List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges
-----------+----------+----------+------------+------------+-----------------------
 mytest    | postgres | UTF8     | en_US.utf8 | en_US.utf8 |
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 |
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres   

So you're accessing the database (which is running in docker on a server) from your localhost.

In this post it's expained in detail.

Solution 2:

I managed to get it run on linux

1. run the docker postgres - make sure the port is published, I use alpine because it's lightweight.

   docker run --rm -P -p 127.0.0.1:5432:5432 -e POSTGRES_PASSWORD="1234" --name pg postgres:alpine
   

2. using another terminal, access the database from the host using the postgres uri

   psql postgresql://postgres:1234@localhost:5432/postgres
   

for mac users, replace psql with pgcli

Solution 3:

You can also access through docker exec command by:

$ docker exec -it postgres-container bash

# su postgres

$ psql

Or

$ docker exec -it postgres-container psql -U postgres

Solution 4:

I am using django with postgres in Docker containers. in the docker-compose file, add the following:

db:
    image: postgres:10-alpine
    environment:
        - POSTGRES_DB=app
        - POSTGRES_USER=postgres
        - POSTGRES_PASSWORD=supersecretpassword
    ports:
        - "6543:5432"

This ports setting uses the port 6543 (it just needs to be different from 5432) that is accessible by your local machine. For myself, I connected DBeaver to it. this will prevent port clashes between your app request and local machine request.

At first, I got a message saying that the port 5432 is in use (which is by django app) so I couldn't access by pgAdmin or DBeaver.