What are Devcontainers and why are they useful?

A Devcontainer uses Docker to create a virtual environment while developing your project. For example, you can run an Ubuntu environment with Python installed, and no matter which machine (Windows, macOS, or Linux) you use, you’ll have a consistent setup.

Benefits:

• Avoid "it works on my machine" issues.
• Simplify collaboration.
• Effortlessly include tools (like the OKD CLI) without manual installs.

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Using DevContainers

As you will see in Veriviz, there is a predefined devcontainer. Running it is the most important thing but if you would like to learn more and how to create one, read the Creating a Devcontainer section below.

Prerequisties

• Docker is strictly nesseary to run a devcontainer and needs to be dowloaded. Check out here for download information(The free version is recommended).
• VsCode is highly recommended. This tutorial will assume you are using VsCode and using any other code editor for a devcontainer will require your own research.
• The Dev Containers Extension in VsCode is needed as well

Re-opening in a devcontainer

1. Press Ctrl+Shift+P (or Cmd+Shift+P on Mac) in VS Code.
2. Choose "Dev Containers: Reopen in Container".
3. VS Code reopens in your dev environment automatically.

Note

Sometimes, VS Code prompts "Reopen folder to develop in a container?". Clicking "Reopen" achienves the same result.

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Creating a Devcontainer

As outlined earlier a devcontainer is extremly useful for collaboration and just a good quality of life thing to have for a repo. Below is an Example devcontainer steup for Rust that is not used in verviz but just her eto provide an example of how to set up a devcontainer.

1. In VS Code, open your project via its root directory
2. Install Dev Containers extension in VS Code
3. create a .devcontainer directory in the root of your project which is the rust-intro directory we just made

   mkdir .devcontainer
   

   This tells the VsCode devcontainers extension there is a devcontainer and it will know to look here
4. Use VS Code and create a file named devcontainer.json inside of the .devcontainer directory. This is where you will define what your devcontainer's skeleton. Look below for an example for a basic Rust container.

{
    "name": "Rust Intro",
    "image": "mcr.microsoft.com/devcontainers/rust:latest",
    "customizations": {
        "vscode":{
            "settings": {},
            "extensions":["rust-lang.rust-analyzer"]
        }
    },    
    "postCreateCommand": "",
}

Here's what everything does

• name: This is what your dev container will be named

• image: The docker image to use, in this case we will be using a preconfigured image for rust by microsoft

• customizations: Adds configurations like VS Code extensions ensuring other developers have them too. rust-lang.rust-analyzer is the standard language server for rust development in vs code.

• postCreateCommand: An optional script to run on container creation

For more info, see VS Code’s Devcontainers docs.