Dev Container via SSH

Why

Microsoft's Dev Containers extension is not available in VSCodium, and third-party alternatives are unstable or require extra tooling. This is a minimal SSH-based setup instead: no telemetry, no extension silently running scripts on your host. Just a Dockerfile you control and one SSH connection.

How it works

you                        docker
───                        ──────
VSCodium ·· SSH:2222 ···>  sshd
.ssh/   ····· mount ····>  .ssh/
                           /app              <─ volume
                           /app/node_modules <─ volume

Prerequisites

1. Install Docker Desktop
2. Install VSCodium with the Open Remote - SSH

Setup

3. Either clone this repo or create the following files manually:

    /
    ├── .env
    ├── compose.yaml
    ├── Dockerfile
    └── entrypoint.sh
   

4. Set APP_NAME (lowercase) and SSH_PORT in .env

   Optionally, set GIT_USER_NAME and GIT_USER_EMAIL to configure git identity globally inside the container.

5. Update the list of Debian packages in Dockerfile if needed.

   Example: add openjdk-25-jre-headless for Java.

   nodejs is included for Node.js development - remove if not needed.

   Note: openssh-server and curl are required.

6. Build the image:

   docker compose build --no-cache

7. Start the container:

   docker compose up --build -d

   On first start, SSH keys are generated in ./.ssh/.

   Note: These are temporary keys used only for the Open Remote - SSH connection. You can delete ./.ssh/ and restart the container to regenerate them.

SSH Configuration

8. Generate a personal password-protected SSH key (skip if you already have one):

   ssh-keygen -t ed25519 -C "your-key-name"

9. Copy that key to ./.ssh/:

    ./.ssh/id_ed25519
   

   It will be used to authenticate with remote Git repositories.

   Security note: Your private SSH key is stored inside the container and accessible to all running code, including npm packages.

   A malicious package could read or exfiltrate it. A strong passphrase is your main line of defense - it will be prompted on every git push.

10. Create ./.ssh/config - this tells SSH which key to use when connecting to a remote Git repository.

    Host codeberg.com
      HostName codeberg.com
      User git
      IdentityFile ~/.ssh/id_ed25519
    

11. Create a dedicated SSH config file somewhere outside your projects, e.g. one level above them: C:/Projects/ssh_config. In VSCodium settings, set remote.SSH.configFile to point to it. (e.g. Cntl , and search remote.SSH.configFile)

    Add an entry:

    Host my-app
      HostName 127.0.0.1
      User user
      Port 2222
      IdentityFile <absolute-path-to-project>/.ssh/id_ed25519_container
    

    This file is separate from your local ~/.ssh/config and contains only container connections. All your projects can share it, just add a new Host block for each one.

12. Connect via Open Remote - SSH, see https://open-vsx.org/extension/jeanp413/open-remote-ssh

    On first connect, open /app in the Explorer manually. Afterwards, directly open /app from the Recent List or use Open Recent / /app [SSH: my-app].

Workspace Initialization

13. In the container terminal:

    chmod 600 ~/.ssh/config ~/.ssh/id_ed25519
    git init
    # Skip if GIT_USER_NAME and GIT_USER_EMAIL are set in .env
    git config --local user.name <your-name>
    git config --local user.email <your-email>
    git remote add origin <remote-repository-url>
    # Skip if starting a new project:
    git fetch
    git checkout -t origin/main
    

    Your project files will be available at /app, persisted on a Docker volume.

Volume Location (Windows)

Files in /app and /app/node_modules are stored in Docker volumes, accessible from the host at:

    \\wsl$\docker-desktop\mnt\docker-desktop-disk\data\docker\volumes\