vscode-dev-containers/containers/python-3-postgres

Python 3 & PostgreSQL

Summary

Develop applications with Python 3 and PostgreSQL. Includes a Python application container and PostgreSQL server.

Metadata	Value
Contributors	The VS Code Python extension team
Categories	Core, Languages
Definition type	Docker Compose
Works in Codespaces	Yes
Available image variants	See Python 3 definition.
Supported architecture(s)	x86-64, arm64/aarch64 for bullseye based images
Container host OS support	Linux, macOS, Windows
Container OS	Debian
Languages, platforms	Python

Using this definition

This definition creates two containers, one for Python and one for PostgreSQL. VS Code will attach to the Python container, and from within that container the PostgreSQL container will be available on localhost port 5432. The default database is named postgres with a user of postgres whose password is postgres, and if desired this may be changed in docker-compose.yml. Data is stored in a volume named postgres-data.

While the definition itself works unmodified, it uses the mcr.microsoft.com/vscode/devcontainers/python image which includes git, eslint, zsh, Oh My Zsh!, a non-root vscode user with sudo access, and a set of common dependencies and Python tools for development. You can pick a different version of this image by updating the VARIANT arg in .devcontainer/docker-compose.yml to pick a Python version.

build:
  context: ..
  dockerfile: .devcontainer/Dockerfile
  args:
    # Update 'VARIANT' to pick a version of Python: 3, 3.10, 3.9, 3.8, 3.7, 3.6
    # Append -bullseye or -buster to pin to an OS version.
    # Use -bullseye variants on local arm64/Apple Silicon.
    VARIANT: 3.7-bullseye

You also can connect to PostgreSQL from an external tool when using VS Code by updating .devcontainer/devcontainer.json as follows:

"forwardPorts": [ "5432" ]

Adding another service

You can add other services to your docker-compose.yml file as described in Docker's documentation. However, if you want anything running in this service to be available in the container on localhost, or want to forward the service locally, be sure to add this line to the service config:

# Runs the service on the same network as the database container, allows "forwardPorts" in devcontainer.json function.
network_mode: service:db

Installing Node.js

Given JavaScript front-end web client code written for use in conjunction with a Python back-end often requires the use of Node.js-based utilities to build, this container also includes nvm so that you can easily install Node.js. You can change the version of Node.js installed or disable its installation by updating the args property in .devcontainer/docker-compose.yml.

args:
  VARIANT: 3.7
  NODE_VERSION: "14" # Set to "none" to skip Node.js installation

Installing or updating Python utilities

This container installs all Python development utilities using pipx to avoid impacting the global Python environment. You can use this same utility add additional utilities in an isolated environment. For example:

pipx install prospector

See the pipx documentation for additional information.

Debug Configuration

Note that only the integrated terminal is supported by the Remote - Containers extension. You may need to modify launch.json configurations to include the following value if an external console is used.

"console": "integratedTerminal"

Using the forwardPorts property

By default, frameworks like Flask only listens to localhost inside the container. As a result, we recommend using the forwardPorts property (available in v0.98.0+) to make these ports available locally.

"forwardPorts": [5000]

The ports property in docker-compose.yml publishes rather than forwards the port, this will not work in a Codespace and applications need to listen to * or 0.0.0.0 for the application to be accessible externally. This conflicts with the defaults of some Python frameworks, but fortunately the forwardPorts property does not have this limitation.

If you've already opened your folder in a container, rebuild the container using the Remote-Containers: Rebuild Container command from the Command Palette (F1) so the settings take effect.

[Optional] Building your requirements into the container image

If your requirements rarely change, you can include the contents of requirements.txt in the container by adding the following to your Dockerfile:

COPY requirements.txt /tmp/pip-tmp/
RUN pip3 --disable-pip-version-check --no-cache-dir install -r /tmp/pip-tmp/requirements.txt \
    && rm -rf /tmp/pip-tmp

Since requirements.txt is likely in the folder you opened rather than the .devcontainer folder, be sure to include context: .. under build in docker-compose.yml. This allows the Dockerfile to access everything in the opened folder instead of just the contents of the .devcontainer folder.

[Optional] Allowing the non-root vscode user to pip install globally without sudo

You can opt into using the vscode non-root user in the container by adding "remoteUser": "vscode" to devcontainer.json. However, by default, this you will need to use sudo to perform global pip installs.

sudo pip install <your-package-here>

Or stick with user installs:

pip install --user <your-package-here>

If you prefer, you can add the following to your Dockerfile to cause global installs to go into a different folder that the vscode user can write to.

ENV PIP_TARGET=/usr/local/pip-global
ENV PYTHONPATH=${PIP_TARGET}:${PYTHONPATH}
ENV PATH=${PIP_TARGET}/bin:${PATH}
RUN if ! cat /etc/group | grep -e "^pip-global:" > /dev/null 2>&1; then groupadd -r pip-global; fi \
    && usermod -a -G pip-global vscode \
    && umask 0002 && mkdir -p ${PIP_TARGET} \
    && chown :pip-global ${PIP_TARGET} \
    && ( [ ! -f "/etc/profile.d/00-restore-env.sh" ] || sed -i -e "s/export PATH=/export PATH=\/usr\/local\/pip-global:/" /etc/profile.d/00-restore-env.sh )

Adding the definition to your folder

1. If this is your first time using a development container, please see getting started information on setting up Remote-Containers or creating a codespace using GitHub Codespaces.

2. Start VS Code and open your project folder or connect to a codespace.

3. Press F1 select and Add Development Container Configuration Files... command for Remote-Containers or Codespaces.

   Note: If needed, you can drag-and-drop the .devcontainer folder from this sub-folder in a locally cloned copy of this repository into the VS Code file explorer instead of using the command.

4. Select this definition. You may also need to select Show All Definitions... for it to appear.

5. Finally, press F1 and run Remote-Containers: Reopen Folder in Container or Codespaces: Rebuild Container to start using the definition.

Testing the definition

This definition includes some test code that will help you verify it is working as expected on your system. Follow these steps:

1. If this is your first time using a development container, please follow the getting started steps to set up your machine.
2. Clone this repository.
3. Start VS Code, press F1, and select Remote-Containers: Open Folder in Container...
4. Select the containers/python-3-postgres folder.
5. After the folder has opened in the container, use ctrl+shift+` to open a terminal and run the following commands to initialize the database and create a super user:

   cd test-project
   pip install --user -r requirements.txt
   python manage.py migrate
   python manage.py createsuperuser
   

6. Next, press F5 to start the project.
7. Once the project is running, press F1 and select Remote-Containers: Forward Port...
8. Select port 5000 and click the "Open Browser" button in the notification that appears.
9. You should see a page with a message indicating the install was successful. You can also go to http://localhost:<port>/admin and sign in.
10. From here, you can add breakpoints or edit the contents of the test-project folder to do further testing.

License

Copyright (c) Microsoft Corporation. All rights reserved.

Licensed under the MIT License. See LICENSE