Building a Rust Docker Image

--- title: Build your Rust image linkTitle: Build images weight: 5 keywords: rust, build, images, dockerfile description: Learn how to build your first Rust Docker image aliases: - /language/rust/build-images/ - /guides/language/rust/build-images/ --- ## Prerequisites - You have installed the latest version of [Docker Desktop](/get-started/get-docker.md). - You have a [git client](https://git-scm.com/downloads). The examples in this section use a command-line based git client, but you can use any client. ## Overview This guide walks you through building your first Rust image. An image includes everything needed to run an application - the code or binary, runtime, dependencies, and any other file system objects required. ## Get the sample application Clone the sample application to use with this guide. Open a terminal, change directory to a directory that you want to work in, and run the following command to clone the repository: ```console $ git clone https://github.com/docker/docker-rust-hello && cd docker-rust-hello ``` ## Create a Dockerfile for Rust Now that you have an application, you can use `docker init` to create a Dockerfile for it. Inside the `docker-rust-hello` directory, run the `docker init` command. `docker init` provides some default configuration, but you'll need to answer a few questions about your application. Refer to the following example to answer the prompts from `docker init` and use the same answers for your prompts. ```console $ docker init Welcome to the Docker Init CLI! This utility will walk you through creating the following files with sensible defaults for your project: - .dockerignore - Dockerfile - compose.yaml - README.Docker.md Let's get started! ? What application platform does your project use? Rust ? What version of Rust do you want to use? 1.70.0 ? What port does your server listen on? 8000 ``` You should now have the following new files in your `docker-rust-hello` directory: - Dockerfile - .dockerignore - compose.yaml - README.Docker.md For building an image, only the Dockerfile is necessary. Open the Dockerfile in your favorite IDE or text editor and see what it contains. To learn more about Dockerfiles, see the [Dockerfile reference](/reference/dockerfile.md). ## .dockerignore file When you run `docker init`, it also creates a [`.dockerignore`](/reference/dockerfile.md#dockerignore-file) file. Use the `.dockerignore` file to specify patterns and paths that you don't want copied into the image in order to keep the image as small as possible. Open up the `.dockerignore` file in your favorite IDE or text editor and see what's inside already. ## Build an image Now that you’ve created the Dockerfile, you can build the image. To do this, use the `docker build` command. The `docker build` command builds Docker images from a Dockerfile and a context. A build's context is the set of files located in the specified PATH or URL. The Docker build process can access any of the files located in this context. The build command optionally takes a `--tag` flag. The tag sets the name of the image and an optional tag in the format `name:tag`. If you don't pass a tag, Docker uses "latest" as its default tag. Build the Docker image. ```console $ docker build --tag docker-rust-image . ``` You should see output like the following. ```console [+] Building 62.6s (14/14) FINISHED => [internal] load .dockerignore 0.1s => => transferring context: 2B 0.0s => [internal] load build definition from Dockerfile 0.1s => => transferring dockerfile: 2.70kB 0.0s => resolve image config for docker.io/docker/dockerfile:1 2.3s

This guide explains how to build your first Rust Docker image. It starts by outlining the prerequisites, such as having Docker Desktop and a git client installed. The guide then walks you through cloning a sample application, creating a Dockerfile using `docker init`, understanding the `.dockerignore` file, and finally building the image using the `docker build` command.