It isn't possible to debug Python Django application

[tolusha]

Description

It isn't possible to debug Python Django application. When Python debug adapter starts debug session for Django application it sends runInTerminal request which starts a django server in side-car container. Since there aren't needed dependencies in the container it fails to start and debug session isn't initialized.

Actually this is a common problem and many debug adapter will face it.

Reproduction Steps

1. Create workspace from python-django dev file [1]
2. Run commands to install dependencies, patch resources and migration
3. Create debug configuration (see below)
4. Try to start debug session
5. Debug failed

[1] https://github.com/eclipse/che-devfile-registry/blob/master/devfiles/python-django/devfile.yaml

OS and version:
Che-7.0.0-rc-4-snapshot

Diagnostics:

        {
            "name": "Python: Django",
            "type": "python",
            "request": "launch",
            "program": "${workspaceFolder}/manage.py",
            "args": [
                "runserver",
                "--noreload"
            ],
            "django": true
        }

[tsmaeder]

@tolusha the "runInTerminal" request is part of the DAP, right? Am I correct that this goes to the theia container and is then routed to the container running the python extension? I think that routing is wrong, conceptually: the tooling container should contain stuff to run the tooling, nothing more.

[tsmaeder]

@tolusha can you start a remote debug session?

[tsmaeder]

This would be 7.0.0 for me if we cannot debug at all. If we have a workaround, 7.1.0

[tolusha]

@tsmaeder

the "runInTerminal" request is part of the DAP, right? Am I correct that this goes to the theia container and is then routed to the container running the python extension

correct

I think that routing is wrong, conceptually: the tooling container should contain stuff to run the tooling, nothing more.

That's arguable. Sidecar container doesn't know anything about other containers.

can you start a remote debug session?

No, I wasn't able.
I will try.

[tolusha]

So, It is possible establish a remote debug session.
At least I can do it in VS Code and Theia IDE, but with Che Theia I got:

Uncaught (in promise) Error: It is not possible to provide debug adapter executable for 'python'. (version: 7.0.0-rc-3.0). This very error has been fixed in recent versions of Theia. But, when I used the latest version of Che Theia I got: Uncaught (in promise) Error: Unknown method $activateByEvent on actor PluginManagerExt

@benoitf Is it something familiar for you?

[tsmaeder]

$activateByEvent is related to activation events being implemented in theia master. It's not in the
theia che-7.0.0 branch.

If we don't have a workaround, we need to escalate.

[tolusha]

We need the latest Theia version

[l0rd]

Why aren't we defining the launch config in the devfile as described here.

@metlos and @RomanNikitenko have worked on handling that (transforming a che command in a vscode launch or task config). We should use that right?

[l0rd]

Oh that's already in Che documentation as well.

[tolusha]

@l0rd
Cool, make sense. I haven't noticed this feature

[tolusha]

I am working on workaround and I will prepare a PR soon.

[tsmaeder]

The issue is still there, even if we have a workaound.

[tsmaeder]

Retargeting to 7.1.0

[l0rd]

@tolusha @tsmaeder can one of you describe the workaround here to help those that have the same issue?

[tolusha]

Currently I am working on redirection runInTerminal request to a dev container. The request above is used to run an application to debug. Current impediments are:

• using an env variable which will point to the dev container [1]. The env variables might be configured in a devfile [2]
• both dev and sidecar containers should use the same version of python
• debug configuration must be adjusted by adding a pythonPath attribute which points to a
  python in the dev container:

{
        "name": "Python: Django",
        "pythonPath": "/usr/bin/python",
        "type": "python",
        "request": "launch",
        "program": "${workspaceFolder}/django-realworld-example-app/manage.py",
        "args": [
            "runserver",
            "--noreload"
        ],
        "django": true
    },

• It is necessary to share /tmp/vscode-unpacked folder files between sidecar and dev containers since it is used to run the application:

[1] https://github.com/eclipse/che-theia/blob/master/extensions/eclipse-che-theia-plugin-remote/src/node/terminal-container-aware.ts#L59
[2] #12555

[tsmaeder]

debug configuration must be adjusted by adding a pythonPath attribute which points to a
python in the dev container:

Shouldn't this be an attribute of the python dev container somehow?

It is necessary to share /tmp/vscode-unpacked folder files between sidecar and dev containers since it is used to run the application:

No, we should use the version of python that is installed in the dev container, IMO.

[tolusha]

No, we should use the version of python that is installed in the dev container, IMO.

It isn't a problem. The problem is that python uses some files from /tm/vscode-unpacked to run the application. These files comes with extensions.

[tsmaeder]

@tolusha you'd have to be more concrete here: what exactly is going on here? I don't understand.

[tolusha]

Have a look at screenshot. That is the command is run in dev container to start the app.
#13816 (comment)

[tsmaeder]

@benoitf @evidolob this would bring us back to the state where plugins are installed in a folder shared by all containers (kind of).

[amisevsk]

@tolusha As a test, is this issue resolved if you add a /tmp/vscode-unpacked/ volume to the workspace devfile?

Currently the only folder shared between theia and sidecars in the /plugins folder. If we also need vscode-unpacked then that's a fairly significant change.

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