Using workspaces in docker builds

[nad-au]

I'm looking to go monorepo and use https://bun.sh/docs/install/workspaces but I'm unsure how to build docker images when the app has one or more workspace dependencies. Currently our dockerfiles are structured as per https://bun.sh/guides/ecosystem/docker

Is anyone doing docker builds from workspaces? Care to share a dockerfile?

[handlebauer]

For anyone else looking to solve this still, compare your approach to:

Project structure:

$ tree -L 3 -I 'node_modules'
.
├── README.md
├── bun.lockb
├── package.json
├── packages
│   ├── pkg-a
│   │   ├── Dockerfile
│   │   ├── README.md
│   │   ├── package.json
│   │   ├── src
│   │   └── tsconfig.json
│   └── pkg-b
│       ├── README.md
│       ├── package.json
│       ├── src
│       └── tsconfig.json
└── tsconfig.json

Dockerfile: ./packages/pkg-a/Dockerfile

# Use the official Bun image
FROM oven/bun:1

# Set working directory
WORKDIR /app

# Copy package.json files
COPY package.json bun.lockb ./
COPY packages/pkg-a/package.json ./packages/pkg-a/
COPY packages/pkg-b/package.json ./packages/pkg-b/

# Install dependencies
RUN bun install --frozen-lockfile

# Copy the rest of the application
COPY . .

# Set the entrypoint to run pkg-a
CMD ["bun", "run", "packages/pkg-a/src/index.ts"]

Build image:

docker build -f packages/pkg-a/Dockerfile -t docker-bun-workspace .

Workspace config mirrors that found @ https://bun.sh/guides/install/workspaces

[nad-au]

Thank you so much @handlebauer I'll be sure to try this

[handlebauer]

Some quick pointers:

• You might encounter an issue during the RUN bun install --frozen-lockfile build step if you have e.g. 5 packages in your workspace and you don't COPY the package.jsons for all of them (even if you're building an image that requires deps from 4 or less those of packages; this was fine for me but could be a dealbreaker depending on context)
• Another RUN bun install --frozen-lockfile related issue may occur unless you downgrade (FROM oven/bun:1.0.35 worked for me, as per [Bug]: Error building Docker image due to msgpackr-extract error with Bun  #12919 (comment))

[janos-r]

1. Doesn't this install all the dependencies of all the packages, just to run one package?
2. Isn't it the same as fist COPY . . and then bun install?

[handlebauer]

I was looking into this quite a while ago now but to your first point, yes, installing deps for all packages was the workaround (at the time; not sure if applicable still). Not 100% on your second point but I see your point and... probably, yes?

[janos-r]

Based on https://dev.to/is_bik/how-create-bun-workspaces-and-build-it-with-docker-51c4
it seams to me that these days one can build just for one app with bun install --filter 'pkg-a'
Looking into it now and considering if to start a monorepo with bun or deno.