VSCode Integration

VSCode has beautiful integration for developing in containers. See here https://code.visualstudio.com/docs/remote/containers for a detailed description of this feature.

When running VSCode with a developer container:

All integrated terminals run inside the container
The test explorer will run tests inside the container
File dialogs will browse the container’s file system
Python and C++ debugging are available for processes running in the container

Initial Setup

Install remote development plugin

Run up VSCode and install the remote development plugin:

module load vscode
code

Then inside VSCode:

Ctrl+P
ext install ms-VSCode-remote.VSCode-remote-extensionpack

Update VSCode User settings

Add the following settings to you user configuration for VSCode in $HOME/.config/Code/User/settings.json

These settings ensures that each terminal loads the bash (login) profile by default. Bash will then run .bash_profile and this includes essential setup for DLS controls developer environment.

"terminal.integrated.defaultProfile.linux": "bash (login)",
"terminal.integrated.profiles.linux": {
    "bash (login)": {
        "args": [
            "-l"
        ],
        "path": "bash"
    }
}

This setting tells remote container development to use podman instead of docker.

"remote.containers.dockerPath": "podman"

How to Use

To use VSCode with a developer container, first add the .devcontainer folder with devcontainer.json file to the root of your project. The script has a helper to do this:

c7 -I

or you can create it manually:

cd <my project folder>
mkdir .devcontainer
cd .devcontainer
wget -q https://raw.githubusercontent.com/dls-controls/dev-c7/main/.devcontainer/devcontainer.json

Then launch VSCode:

cd <my project folder>
module load vscode
code .

Click on Reopen in Container when you see a dialogue with the message Folder contains a Dev Container configuration file.

Close the first terminal that you see and open another one (see Known Issues)

That’s it, you are now running a developer container and your vscode session is connected to it.

The above gets version 2.0.0 which is current as of 01/07/2022. See https://github.com/dls-controls/dev-c7/releases for the latest updates.

Container Lifetime

Like the c7 script, the container will be kept alive. If you exit and re-enter VSCode you will be reconnected to the same container.

When you run podman ps you will see the container is running and is named something like this:

localhost/vsc-dev-c7-914745539fc385a5fe9188693f0fa257-uid

You can recreate the container from scratch by deleting it with podman rm or you can tell VSCode to rebuild it using the remotes menu. This menu is accessed by clicking the icon in the very bottom left of the VSCode window.

The remotes menu option Rebuild Container will close the session, rebuild the container and reopen the session in the new container.

Note that this means that the containers used by VSCode and those used by c7 are distinct. So if you install something into one it will not be seen in the other.

Note

VSCode will use a different container for each folder. If you would like to share a container between folders:

open multiple folders in a single VSCode session by choosing “Add Folder to Workspace” from the right click menu in the File Explorer
choose File->Save Workspace As... and save the workspace to a file, usually in the folder that is a common root to your projects.
copy the .devcontainer folder to the same folder as the workspace file.
go to the remotes menu (icon in bottom left of VSCode) and choose Reopen Container

VSCode Container Removal

If you want to remove all of the containers that VSCode has created then the following will do the trick:

podman rmi -f $(podman images --filter=reference='*vsc-*' -q)

This may be useful if you are having trouble with VSCode devcontainers or if you are running low on disk space.

Known Issues

First integrated terminal

When a devcontainer is launched, it will usually start a single terminal that is NOT using the login profile. This means you won’t see your usual bash prompt and none of the DLS development environment will be available.

To work around this, close and reopen the 1st terminal or type:

bash -l