Awesome
DevContainer CLI Port Forwarder
Overview
This Python script dynamically forward ports from a host machine to a Docker container according to devcontainer.json
forwardPorts.
This Python script is created because currently DevContainer CLI does not support port forwarding, see devcontainers/cli issue
Usage Context
- This script is only needed if you are managing your containers directly with the devcontainer CLI.
- If you are using vSCode with the Visual Studio Code Dev Containers extension,The VS Code extension already includes built-in support for port forwarding you do not need to use this script.
Prerequisites
- host machine: Python 3 interpreter is installed.
- container:
socat
is installed.
Features
- Dynamic Port Forwarding: Automates the process of forwarding specified ports from the host to a Docker container.
- Automatic Shutdown: The script automatically exits when the associated Docker container stops running.
Installation
git clone this project under your project's .devcontainer
directory, or anywhere you like.
git clone https://github.com/nohzafk/devcontainer-cli-port-forwarder.git .devcontainer/devcontainer-cli-port-forwarder
This script won't automatically install socat
inside the container for you, you need to install socat
inside the container.
you can simply add a line in onCreateCommand in your devcontainer.json
"onCreateCommand": "sudo apt update && sudo apt install -y socat",
or use nix feature
"features": {
"ghcr.io/devcontainers/features/nix:1": {
"packages": "socat"
}
},
Usage
In your devcontainer.json, set the initializeCommand
to run the script in the background when the container is being initialized:
"initializeCommand": "python3 .devcontainer/devcontainer-cli-port-forwarder/forwarder.py &",
To enable verbose output, which provides more detailed information about the port forwarding process, modify the initializeCommand as follows:
"initializeCommand": "python3 .devcontainer/devcontainer-cli-port-forwarder/forwarder.py verbose &",
and finally specify the ports that you want to forward from host by forwardPorts,
for example port 2222 used by devcontainer feature sshd "ghcr.io/devcontainers/features/sshd:1": {},
Use 'forwardPorts' to make a list of ports inside the container available locally.
"forwardPorts": [2222],
Once configured in your devcontainer.json, the script will automatically start when you create a devcontainer using the devcontainer CLI. It listens on specified ports and forwards them to the Docker container.
- The script runs in the background and does not require manual intervention once started.
- When the Docker container stops, the script detects this and exits automatically, ensuring that resources are not left unnecessarily consumed on the host machine.