PostgreSQL and pgAdmin both running in Docker containers and connecting

Question

I am attempting to run both PostgreSQL and pgAdmin in Docker containers. The idea is that the PostgreSQL database should be accessible to any applications I have running on the host machine, and also to pgAdmin.

I am using this command to run PostgreSQL:

docker run -d -e POSTGRES_USER=username -e POSTGRES_PASSWORD=password --name postgres -p 5432:5432 postgres

And to run pgAdmin:

docker run -d -p 1111:1111 --name pgadmin -e "PGADMIN_LISTEN_PORT=1111" -e "PGADMIN_DEFAULT_EMAIL=admin@test.com" -e "PGADMIN_DEFAULT_PASSWORD=test" dpage/pgadmin4

If I go to localhost:1111, I can connect to pgAdmin and login. However, when I try to connect to my local PostgreSQL instance, it gets no response.

Therefore, I tried to run pgAdmin with access to the host internet using --net=host instead of -p 1111:1111:

docker run -d --net=host --name pgadmin -e "PGADMIN_LISTEN_PORT=1111" -e "PGADMIN_DEFAULT_EMAIL=admin@test.com" -e "PGADMIN_DEFAULT_PASSWORD=test" dpage/pgadmin4

Now, when I try to go to localhost:1111 to connect to pgAdmin, I get no response in my browser.

Docker Compose is a possible solution, as I could link the two containers together so they could access each other without having to worry about ports, but I also need pgAdmin to be able to access PostgreSQL instances on other machines, as well as my local one.

I feel like --net=host is broken in Docker. There's a whole thread here with a lot of confusion.

My setup:

Host: Windows 10
Docker: Docker Desktop Community v2.0.0.3 (31259)

Update

I have now tried using --link postgres on the pgAdmin container and it allows me to connect to my local instance of PostgreSQL but not non-local ones, the full command is:

docker run -d -p 1111:1111 --link postgres --name pgadmin -e "PGADMIN_LISTEN_PORT=1111" -e "PGADMIN_DEFAULT_EMAIL=admin@test.com" -e "PGADMIN_DEFAULT_PASSWORD=test" dpage/pgadmin4

I have the "same" problem last week https://stackoverflow.com/questions/55928586/problem-with-postgresql-and-pgadmin-docker-containers , Hope this help you. — Schwarz54, May 10 '19 at 08:53
@Schwarz54 The accepted answer on your post is a little bit useful, I have now found that using `--link postgres` will at least let pgAdmin access just my local instance of PostgreSQL but I also need it to be able to access any non-local ones too. — harvzor, May 13 '19 at 07:47

score 2 · Accepted Answer · answered May 15 '19 at 13:47

The commands were not wrong, only the connection in pgAdmin, so the full list of commands are:

For PostgreSQL:

docker run -d -e POSTGRES_USER=username -e POSTGRES_PASSWORD=password --name postgres -p 5432:5432 postgres

And pgAdmin:

docker run -d -p 1111:1111 --name pgadmin -e "PGADMIN_LISTEN_PORT=1111" -e "PGADMIN_DEFAULT_EMAIL=admin@test.com" -e "PGADMIN_DEFAULT_PASSWORD=test" dpage/pgadmin4

Now the pgAdmin container won't connect to localhost but needs the IP of the PostgreSQL container. Run:

docker inspect postgres

Inspect result:

[
    {
        ...
        "NetworkSettings": {
            ...
            "Networks": {
                ...
                "IPAddress": "172.17.0.3",
                ...
            }
        }
    }
]

We're only interested in the IPAddress from the inspect command. This is the IP which pgAdmin should connect to.

pgAdmin is also capable of access external IPs from your machine.

But the ips would change when we restart the container correct? How do we refer to the container in a more persistent manner? — hakish, Aug 14 '20 at 10:23
@hakish I'd recommend using Docker Compose. Containers in the same yaml file can connect to each other using the name of the container (such as `postgres:5432`). I have a blogpost which is half finished you might want to look at: https://github.com/Harvzor/portfolio/blob/docker-blogpost/data/blog/docker.md#adding-pgadmin — harvzor, Aug 18 '20 at 12:04

score 0 · Answer 2 · answered May 10 '19 at 08:49

When you create docker containers it creates a bridge network. First find the network range for the bridge network. You can use ifconfig to find it. Let's say 172.17.0.5 is ip of pgAdmin, Then create a user 'root'@'172.17.0.5' for PostgreSQL and give database permissions for that user. Then you can connect to the database. Also check if port 3306 is accessible using telnet.

PostgreSQL and pgAdmin both running in Docker containers and connecting

Update

2 Answers2