Unable to connect to Postgres container on EC2 instance

[agundu-mdsol]

Hi,
We have setup an EC2 instance where we installed docker and required containers. We are using this EC2 instance as a codebuild executor. Once the code pushes to GIT it will trigger the codebuild where the containers will be used to reproduce an actual execution scenario.

Our issue is, except postgres all other containers are accepting connections from external systems. We checked the inbound and outbound rules where the port 5432 is allowed for access. when we checked on the EC2 node, we are seeing that 5432 port is in LISTEN state. we are not able to figure out this. Appreciate if we get some help. Thanks

2021-02-05 12:28:14.348 UTC [1] LOG: starting PostgreSQL 13.1 (Debian 13.1-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
2021-02-05 12:28:14.348 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432
2021-02-05 12:28:14.348 UTC [1] LOG: listening on IPv6 address "::", port 5432
2021-02-05 12:28:14.356 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
2021-02-05 12:28:14.365 UTC [63] LOG: database system was shut down at 2021-02-05 12:28:14 UTC
2021-02-05 12:28:14.375 UTC [1] LOG: database system is ready to accept connections

I am able to connect from host machine to container using psql cli

[wglambert]

Can you give all the commands you ran and any relevant files for reproducing the issue

You could also try asking over at the Docker Community Forums, Docker Community Slack, or Stack Overflow. Since these repos aren't really a user-help forum

[agundu-mdsol]

We have installed docker engine in EC2 instance using the below commands

sudo su -
Uninstall older versions
apt-get remove docker docker-engine
Setup Docker repository
apt-get update
apt-get install apt-transport-https ca-certificates curl software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
Install docker community edition
apt-get update
apt install -y docker-ce=18.06.1ce3-0~ubuntu

After that we ran the postgres container startup using the below command.

docker run -d --name postgres-local -p 5432:5432 -e POSTGRES_USER=postgres -e POSTGRES_PASSWORD=postgres -e POSTGRES_DATABASE=db_lab postgres

we are able to connect from the EC2 instance(Host) to the container using psql command line.

We are able to get connections to other containers which are active on the EC2 node.

We tried starting the postgres on other port like 3306 to check if it can be accessible. when we did that it got the connection to postgres on 3306 port. but on 5432 port it is not letting connections.

We already allowed inbound and outbound rules to get connections to 5432

[tianon]

I would not recommend exposing your database container to the public internet, even with a strong password. We've seen case after case of folks doing so and getting hacked as a result.

That being said, this doesn't sound like an issue with the image, and is definitely related to usage or environment (for example, to make -p 5432:5432 work, you'll need to configure PostgreSQL inside the container to listen on that port; what you probably intended instead was -p 5432:3306), so I'd suggest trying a dedicated support forum, such as the Docker Community Forums, the Docker Community Slack, or Stack Overflow for further help.