tasks.json: dockerRun volumes: support bind?

[eddieparker]

I often find it handy to 'bind' a volume to the host for development purposes. It helps me iterate quickly on things like Flask while in dev mode.

I can't seem to make that happen with the current syntax: it only makes a 'volume' mount. Would it be possible (or is it already somehow?) to expose the 'type' variable so I can bind volumes?

[bwateratmsft]

Related to #2259 I think. Probably the best approach for both is to add a catch-all "bring your own parameters" field to the docker-run and docker-build tasks.

[eddieparker]

That would be great! Or, alternatively if i could somehow have the docker run thing actually use my docker compose setup? I dunno if that's possible however.

[bwateratmsft]

Depending on what you're doing it's possible that you don't need to use the docker-run task, but can instead have your own shell task that calls docker-compose up. Are you using the tasks for debugging or just to get a container running?

We tried to design our debugging experience so that the docker-run tasks are not mandatory--thus, users could come up with their own run tasks if they needed more advanced customization. (If that isn't working then I'd consider that a bug we need to fix.)

[eddieparker]

I'm exploring the docker debugging in vscode. Can the docker debug use docker compose via shell?

[bwateratmsft]

Most likely yes. Which platform are you debugging? (.NET Core, Node, Python)

[eddieparker]

Python. A flask app to be specific.

[bwateratmsft]

Gotcha. Your best bet is to make use of the Python attach configuration. Here's a setup that works for me, although it was behaving a little weirdly, it seemed to compose-up then do nothing, then I F5'd again, it'd try compose-up again and say it's up to date, then actually attach.

The entrypoint in docker-compose.debug.yml is important; it is instructing debugpy to start the Flask app up and wait for a debugger to attach (from VSCode).

Dockerfile:

# For more information, please refer to https://aka.ms/vscode-docker-python
FROM python:3.8-slim-buster

EXPOSE 5000

# Keeps Python from generating .pyc files in the container
ENV PYTHONDONTWRITEBYTECODE 1

# Turns off buffering for easier container logging
ENV PYTHONUNBUFFERED 1

# Install pip requirements
ADD requirements.txt .
RUN python -m pip install -r requirements.txt

WORKDIR /app
ADD . /app

# Switching to a non-root user, please refer to https://aka.ms/vscode-docker-python-user-rights
RUN useradd appuser && chown -R appuser /app
USER appuser

# During debugging, this entry point will be overridden. For more information, please refer to https://aka.ms/vscode-docker-python-debug
CMD ["gunicorn", "--bind", "0.0.0.0:5000", "app:app"]

docker-compose.yml:

version: '3.4'

services:
  flasktasktest:
    image: flasktasktest
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - 5000

docker-compose.debug.yml:

version: '3.4'

services:
  flasktasktest:
    image: flasktasktest
    build:
      context: .
      dockerfile: Dockerfile
    entrypoint: /bin/bash
    command: -c "pip install debugpy -t /tmp && python /tmp/debugpy --wait-for-client --listen 0.0.0.0:5678 -m flask run --no-debugger --no-reload --host 0.0.0.0 --port 5000"
    ports:
      - 5000:5000
      - 5678:5678
    environment:
      - FLASK_APP=app.py

tasks.json:

{
    "version": "2.0.0",
    "tasks": [
        {
            "type": "shell",
            "label": "Compose Up",
            "command": "docker-compose -f docker-compose.yml -f docker-compose.debug.yml up -d"
        }
    ]
}

launch.json:

{
    "configurations": [
        {
            "name": "Python: Remote Attach",
            "type": "python",
            "request": "attach",
            "connect": {
                "host": "localhost",
                "port": 5678
            },
            "pathMappings": [
                {
                    "localRoot": "${workspaceFolder}",
                    "remoteRoot": "."
                }
            ],
            "preLaunchTask": "Compose Up"
        }
    ]
}

[bwateratmsft]

This is now fixed in Docker extension version 1.7.0.