Docker Dev Container Example

This repository provides an example setup for developing a simple Streamlit application using a Docker Container.

Prerequisites

• Docker installed on your machine
• Visual Studio Code with the Remote Containers extension installed

Usage

1) Starting and Stopping the Dev Container

docker-compose up
docker-compose down

Start the container in detached mode (runs in the background):

docker-compose up -d

Re-build the image if you have made changes to the Dockerfile or dependencies:

docker-compose up --build

2) Attaching VS Code to the Running Container

To attach Visual Studio Code to the running container:

1. Open the Command Palette (Ctrl+Shift+P or Cmd+Shift+P on macOS).
2. Select Dev Containers: Attach to Running Container....
3. Choose the appropriate container from the list.

Accessing the Streamlit App

Once the container is running, you can access your Streamlit app in your browser at http://localhost:8501.

Additional Information

Dockerfile

• FROM python:3.11-slim - This line specifies the base image to use, which is python:3.11-slim. This image is lightweight and includes Python 3.11.
• WORKDIR /code - Sets the working directory inside the container to /code. This is where the application code will be placed.
• COPY requirements.txt . - Copies requirements.txt from your local directory into the container's /code directory.
• RUN pip install --no-cache-dir -r requirements.txt - Installs the Python dependencies listed in requirements.txt into the container without caching to minimize image size.
• ENTRYPOINT ["/bin/bash", "-l", "-c"] - Sets the default executable for the container. This configuration allows you to run commands in a login shell mode.
• CMD ["streamlit run ./src/app.py"] - Specifies the default command to run when the container starts. In this case, it runs a Streamlit application located at ./src/app.py.

docker-compose.yml

• version: "3" - Specifies the version of Docker Compose file format being used
• services - Defines the services that make up your application
• app - The name of your service
• build: ./ - Specifies the build context. In this case, it builds the Dockerfile located in the current directory (./)
• container_name: python-server - Sets the container name to python-server
• ports: 127.0.0.1:8501:8501 - Maps port 8501 on your local machine to port 8501 inside the container. This allows you to access the Streamlit app running inside the container at http://localhost:8501
• volumes: ./:/code - Mounts the current directory (./) as a volume inside the container at /code. This allows changes made on your local machine to be reflected immediately inside the container
• restart: unless-stopped - Specifies the restart policy for the container. It ensures that the container restarts automatically unless it is explicitly stopped