Visual Studio Code debugs python 2.7 app in a docker container with python3

[LeiteMarga]

Hi there,

I am having some trouble getting my debugger to work in VS Code and from the error messages below, I gather that there is a discrepancy between the python versions. The legacy app I am working on is using Python 2.7.

I have come across this similar issue: Issue reference , however still can't get it to work.

Is there anything obvious that I'm missing? Any assistance will be greatly appreciated.

• I'm using a Mac OS

Pop up Error 1:
Invalid message: "debugLauncherPath" must be str

Terminal error:
docker run -dt -P --name "app_name-dev" --label "com.microsoft.created-by=visual-studio-code" -v "/User/.vscode/extensions/ms-python.python-2021.10.1365161279/pythonFiles/lib/python/debugpy:/debugpy:ro,z" --entrypoint "python3" "app_name:latest" <

My configurations are:

launch.json
{
"version" : "0.2.0",
"configurations": [
{
"name": "Docker: Python - Django",
"type": "docker",
"request": "launch",
"preLaunchTask": "docker-run: debug",
"python": {
"pathMappings": [
{
"localRoot": "${workspaceFolder}",
"remoteRoot": "/app"
}
],
"projectType": "django",
},
},
]
}

tasks.json:
{
"version": "2.0.0",
"tasks": [
{
"type": "docker-build",
"label": "docker-build",
"platform": "python",
"dockerBuild": {
"tag": "app_name:latest",
"dockerfile": "${workspaceFolder}/docker/DockerFileLocal",
"context": "${workspaceFolder}",
"pull": true
}
},
{
"type": "docker-run",
"label": "docker-run: debug",
"dependsOn": [
"docker-build"
],
"python": {
"args": [
"runserver",
"0.0.0.0:8000",
"--nothreading",
"--noreload"
],
"file": "manage.py"
}
}
]
}

settings.py
{
"workbench.colorTheme": "One Dark Pro",
"git.autofetch": true,
"[jsonc]": {
"editor.defaultFormatter": "vscode.json-language-features"
},
"[html]": {
"editor.defaultFormatter": "esbenp.prettier-vscode"
},

"files.exclude": {
    "**/__pycache__": true,
    "**/*.pyc"      : true
    },

"[python]": {

    "editor.rulers": [79]},
    "editor.multiCursorModifier"     : "alt",
    "python.languageServer"          : "Jedi",
    "python.analysis.cacheFolderPath": "lint",
    "python.defaultInterpreterPath"  : "~/.pyenv/versions/2.7.13/envs/app_name/bin/python",
    "python.linting.enabled"         : true,
    "python.linting.pylintEnabled"   : true,
    "python.linting.flake8Enabled"   : true,
    "python.linting.flake8Path"      : "~/.pyenv/versions/2.7.13/envs/app_name/bin/flake8",
    "python.linting.flake8Args"      : ["--config=pep8_test","APP/"],
    "typescript.validate.enable"     : false,
    "javascript.validate.enable"     : false,
    "gitlens.blame.format"           : "${author}${agoOrDate|14-}",
    "git.confirmSync"                : false,
    "redhat.telemetry.enabled"       : false,
    "files.autoSave"                 : "afterDelay",

}

manage.py
import os
import sys

if name == "main":
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "APP.settings")

from django.core.management import execute_from_command_line

execute_from_command_line(sys.argv)

[bwateratmsft]

It looks like after one of your edits the terminal error message isn't there, can you share it?

[LeiteMarga]

Yes, I edited out one of the errors that I fixed after my original post. This is the updated terminal error log:

Executing task: docker-run: debug <

docker run -dt -P --name "app-name-dev" --label "com.microsoft.created-by=visual-studio-code" -v "/Users/margaleite/.vscode/extensions/ms-python.python-2021.10.1365161279/pythonFiles/lib/python/debugpy:/debugpy:ro,z" --entrypoint "python3" "app-name:latest" <

f278998e488d1be3880ec1f095c60d362c3501cac9be399dc9635f92abb098fc

Terminal will be reused by tasks, press any key to close it.

[LeiteMarga]

In the related issue that I referenced, they mention adding the below to the Python entry point file. I assume this refers to the manage.py file in Django, but couldn't get it to work. Is the entry point file perhaps somewhere else?

*I have ptvsd (4.3.2) installed, but in the current state am not importing it anywhere as per the below code from the related issue:

import ptvsd
ptvsd.enable_attach(address=('0.0.0.0', 5678))

[bwateratmsft]

Aha, I missed this part when I read your post the first time:

The legacy app I am working on is using Python 2.7.

Obviously I have to recommend working on migrating the app to Python 3+, as Python 2 has been end-of-life for a couple of years now.

ptvsd is no longer used for debugging Python apps, now debugpy is used. I'm not sure if debugpy is compatible with Python 2.7. @int19h is there a way to still use ptvsd for debugging? Or is the best bet here to install an older version of the Docker and Python extensions?

[LeiteMarga]

Hi Brandon, yes it's definitely high priority for us to upgrade the system in the next couple of months, however I am new to the project and it will help a lot if I can get the debugger to work in the meantime as well.

[bwateratmsft]

@LeiteMarga One thing that might work is to use a Python attach configuration instead of direct launch.

1. Add a Python: Remote Attach launch configuration:

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

2. Right click the docker-compose-debug.yml file added by Dockerfile scaffolding, and do "Compose Up"
3. Select the remote attach configuration and hit F5

[int19h]

debugpy is no longer compatible with anything earlier than Python 3.7. However, earlier versions of debugpy were compatible with Python 2.7, and can still be used for "attach" / debugpy.listen() debugging. If you do pip install debugpy from a Python 2.7 environment, that should get you the most recent version that is still compatible.

[LeiteMarga]

Thank you so much for the feedback - really appreciate it! We managed to get it to work using ptvsd with the following configurations:

manage.py
from django.conf import settings

if settings.DEBUG:
    print(os.environ.get('RUN_MAIN') or os.environ.get('WERKZEUG_RUN_MAIN'))
    if os.environ.get('RUN_MAIN') or os.environ.get('WERKZEUG_RUN_MAIN'):
        import ptvsd
        ptvsd.enable_attach(address = ('0.0.0.0', 3000))
        print "Attached remote debugger"

launch.json
{
"name": "Django",
"type": "python",
"request": "attach",
"pathMappings": [
{
"localRoot": "${workspaceFolder}",
"remoteRoot": "/app"
}
],
"port": 3000,
"host": "localhost"
}

docker-compose.yml
ports:
- "8000:8000"
- "3000:3000"

[bwateratmsft]

Great news! Glad it's working now.