Tools: Dev Containers: Rust Quick Start

Introduction ## Requirements ## Adding the Dev Container configuration ## Hello World Rust Template ## Testing the environment isolation Dev Containers let you use Docker to run an isolated development environment, so that your tooling and runtime stack can live “somewhere else” instead of on your host machine. ​ A devcontainer.json file in your repo defines how to create or connect to that development container (and which tools/extensions/settings to include). ​ Dev Containers have become pretty mainstream lately, and I’m finding them especially useful in several scenarios, for instance when I need to temporarily set up a development environment or a specific toolchain for a quick test I'll later discard, and I don't want to pollute my host machine. To follow this tutorial, you need to have: I tested this on Ubuntu 24.04 on WSL2 (Windows 11), but it should work on any platform supported by Docker and VS Code, with minor adjustments. First of all, let's create our project folder: Then, let's create a file called .devcontainer/devcontainer.json in the project root with the following content: If you haven't done it yet, open the project root folder with VS Code: Then use the Command Palette (Ctrl + Shift + P), and select Dev Containers: Reopen in Container. This command may take a while the first time as Docker needs to download the base image and set up the container. Once finished, the blue bottom-left corner of VS Code should indicate that you are connected to the Dev Container. As an additional confirmation, you can open a terminal in VS Code and see that the environment looks different from your host machine (e.g., the current user is vscode). At this point, you can continue working as usual; the fact that you are inside a Dev Container is mostly transparent. To test the Dev Container with Rust, we need at least a minimal project that can be compiled, run, and eventually debugged. To do so, let's open a VS Code terminal and type: You should see the "Hello, world!" string printed to the terminal. The same could be done directly from VS Code by clicking on the buttons on top of the main() function. Debugging works as well. To verify that the Dev Container is indeed isolated from your host machine, let's suppose that we want to test our "Hello World" Rust application with the latest nightly toolchain. We could install it on our host machine, but maybe we won't need it beyond this quick test, and we are too lazy to uninstall it later. Instead, we can simply install it inside the Dev Container. To force cargo to use a specific toolchain version, let's create a file called rust-toolchain.toml in the project root with the following content: VS Code should automatically detect the change and attempt to refresh the project, but the Rust Analyzer extension may fail as the specified toolchain is not yet installed inside the Dev Container. If you open the extension log, you should see an error like this: Let's accept the suggestion and run the command in the VS Code terminal inside the Dev Container: Once finished, you may need to restart Rust Analyzer, and then the IDE is fully functional again. You can notice, for instance, that we can run or debug the application by clicking on the buttons on top of the main() function. Since I prefer to verify rather than trust, let's make a quick check. From the IDE terminal, run rustup show. It lists the toolchains installed on the Dev Container, and should include nightly-2026-01-15. Now, if you have Rustup installed on the host machine, you can do the same and compare the output: that toolchain version should not appear unless you installed it on your own, regardless of this tutorial. Templates let you quickly answer FAQs or store snippets for re-use. Are you sure you want to hide this comment? 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Hide child comments as well For further actions, you may consider blocking this person and/or reporting abuse CODE_BLOCK: mkdir hello-dev-container && cd hello-dev-container Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: mkdir hello-dev-container && cd hello-dev-container CODE_BLOCK: mkdir hello-dev-container && cd hello-dev-container CODE_BLOCK: { "name": "Rust Hello World (Dev Container)", "image": "mcr.microsoft.com/devcontainers/rust:latest", "customizations": { "vscode": { "extensions": ["rust-lang.rust-analyzer"] } } } Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: { "name": "Rust Hello World (Dev Container)", "image": "mcr.microsoft.com/devcontainers/rust:latest", "customizations": { "vscode": { "extensions": ["rust-lang.rust-analyzer"] } } } CODE_BLOCK: { "name": "Rust Hello World (Dev Container)", "image": "mcr.microsoft.com/devcontainers/rust:latest", "customizations": { "vscode": { "extensions": ["rust-lang.rust-analyzer"] } } } CODE_BLOCK: code . Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: cargo init --bin --name hello-dev-container cargo run Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: cargo init --bin --name hello-dev-container cargo run CODE_BLOCK: cargo init --bin --name hello-dev-container cargo run CODE_BLOCK: [toolchain] channel = "nightly-2026-01-15" Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: [toolchain] channel = "nightly-2026-01-15" CODE_BLOCK: [toolchain] channel = "nightly-2026-01-15" CODE_BLOCK: toolchain 'nightly-2026-01-15-x86_64-unknown-linux-gnu' is not installed help: run `rustup toolchain install` to install it Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: toolchain 'nightly-2026-01-15-x86_64-unknown-linux-gnu' is not installed help: run `rustup toolchain install` to install it CODE_BLOCK: toolchain 'nightly-2026-01-15-x86_64-unknown-linux-gnu' is not installed help: run `rustup toolchain install` to install it CODE_BLOCK: rustup toolchain install Enter fullscreen mode Exit fullscreen mode CODE_BLOCK: rustup toolchain install CODE_BLOCK: rustup toolchain install - Visual Studio Code with the "Dev Containers" extension installed