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This guide assumes you already have Docker Desktop installed.
Docker is a platform for packaging and running an application as a lightweight, portable container that encapsulates all the necessary dependencies.
To containerize our application, we define a Dockerfile. This file contains a list of instructions to initialize the container, copy our local project files into it, install dependencies, and starts the application.
Dockerfile
# use the official Bun image # see all versions at https://hub.docker.com/r/oven/bun/tags FROM oven/bun:1 AS base WORKDIR /usr/src/app  # install dependencies into temp directory # this will cache them and speed up future builds FROM base AS install RUN mkdir -p /temp/dev COPY package.json bun.lock /temp/dev/ RUN cd /temp/dev && bun install --frozen-lockfile  # install with --production (exclude devDependencies) RUN mkdir -p /temp/prod COPY package.json bun.lock /temp/prod/ RUN cd /temp/prod && bun install --frozen-lockfile --production  # copy node_modules from temp directory # then copy all (non-ignored) project files into the image FROM base AS prerelease COPY --from=install /temp/dev/node_modules node_modules COPY . .  # [optional] tests & build ENV NODE_ENV=production RUN bun test RUN bun run build  # copy production dependencies and source code into final image FROM base AS release COPY --from=install /temp/prod/node_modules node_modules COPY --from=prerelease /usr/src/app/index.ts . COPY --from=prerelease /usr/src/app/package.json .  # run the app USER bun EXPOSE 3000/tcp ENTRYPOINT [ "bun", "run", "index.ts" ]
Now that you have your docker image, let’s look at .dockerignore which has the same syntax as .gitignore, here you need to specify the files/directories that must not go in any stage of the docker build. An example for a ignore file is
.dockerignore
node_modules Dockerfile* docker-compose* .dockerignore .git .gitignore README.md LICENSE .vscode Makefile helm-charts .env .editorconfig .idea coverage*
We’ll now use docker build to convert this Dockerfile into a Docker image, a self-contained template containing all the dependencies and configuration required to run the application. The -t flag lets us specify a name for the image, and --pull tells Docker to automatically download the latest version of the base image (oven/bun). The initial build will take longer, as Docker will download all the base images and dependencies.
terminal
docker build --pull -t bun-hello-world . 
[+] Building 0.9s (21/21) FINISHED  => [internal] load build definition from Dockerfile 0.0s  => => transferring dockerfile: 37B 0.0s  => [internal] load .dockerignore 0.0s  => => transferring context: 35B 0.0s  => [internal] load metadata for docker.io/oven/bun:1 0.8s  => [auth] oven/bun:pull token for registry-1.docker.io 0.0s  => [base 1/2] FROM docker.io/oven/bun:1@sha256:373265748d3cd3624cb3f3ee6004f45b1fc3edbd07a622aeeec17566d2756997 0.0s  => [internal] load build context 0.0s  => => transferring context: 155B 0.0s  # ...lots of commands...  => exporting to image 0.0s  => => exporting layers 0.0s  => => writing image sha256:360663f7fdcd6f11e8e94761d5592e2e4dfc8d167f034f15cd5a863d5dc093c4 0.0s  => => naming to docker.io/library/bun-hello-world 0.0s
We’ve built a new Docker image. Now let’s use that image to spin up an actual, running container. We’ll use docker run to start a new container using the bun-hello-world image. It will be run in detached mode (-d) and we’ll map the container’s port 3000 to our local machine’s port 3000 (-p 3000:3000). The run command prints a string representing the container ID.
terminal
docker run -d -p 3000:3000 bun-hello-world 
7f03e212a15ede8644379bce11a13589f563d3909a9640446c5bbefce993678d
The container is now running in the background. Visit localhost:3000. You should see a Hello, World! message.
To stop the container, we’ll use docker stop <container-id>.
terminal
docker stop 7f03e212a15ede8644379bce11a13589f563d3909a9640446c5bbefce993678d
If you can’t find the container ID, you can use docker ps to list all running containers.
terminal
docker ps 
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 7f03e212a15e bun-hello-world "bun run index.ts" 2 minutes ago Up 2 minutes 0.0.0.0:3000->3000/tcp flamboyant_cerf
That’s it! Refer to the Docker documentation for more advanced usage.