ansiblings/packages/nopy/README.DOCKER.md

Testing Nopy with Docker

This guide explains how to set up a local Docker container to test nopy deployments using the provided Ubuntu-24LTS.Dockerfile and example.nopysession.json.

Prerequisites

• Docker installed and running on your machine.
• nopy installed and linked (see README.md).

1. Setup SSH Key (Important)

The provided Ubuntu-24LTS.Dockerfile contains a hardcoded public SSH key. Before building, you must replace it with your own public key to allow SSH access (if needed) or ensure pyinfra can connect if it uses SSH transport.

1. Open Ubuntu-24LTS.Dockerfile.
2. Locate the line starting with echo "ssh-ed25519 ....
3. Replace the key string with the content of your own public key (usually ~/.ssh/id_ed25519.pub or ~/.ssh/id_rsa.pub).

# Example replacement
RUN mkdir -p /home/testuser/.ssh && \
    echo "YOUR_PUBLIC_KEY_HERE" >> /home/testuser/.ssh/authorized_keys && \
    ...

2. Build the Docker Image

Run the following command from the packages/nopy directory:

docker build -f Ubuntu-24LTS.Dockerfile -t nopy-test-ubuntu .

3. Run the Container

Start the container in the background. We explicitly name it nopy-test-container because the example.nopysession.json is configured to target this specific container name.

docker run -d \
  --name nopy-test-container \
  --privileged \
  -p 2222:22 \
  nopy-test-ubuntu

• --name nopy-test-container: Matches the host defined in example.nopysession.json.
• --privileged: Required for some system-level operations (like criu or service management) if tested.
• -p 2222:22: Maps the container's SSH port to local port 2222 (optional, allows manual SSH connection).

4. Deploy using Nopy

Now you can run the example session. Nopy uses pyinfra's @docker connector to communicate directly with the container, so SSH keys are not strictly required for the deployment itself, but the session is configured to simulate a realistic environment.

nopy install -l example.nopysession.json

If successful, nopy will execute the apt:essentials cube against the container.

5. Manual Verification

You can connect to the container manually to verify changes:

Via Docker Exec:

docker exec -it nopy-test-container bash

Via SSH (if configured):

ssh -p 2222 testuser@localhost
# Password: password

6. Cleanup

To stop and remove the container:

docker rm -f nopy-test-container