Builds

freepod deploy uploads the project directory and builds a container image from it on Freepod. No local Docker installation is needed.

Builders

Project root contains	Builder
Dockerfile	The Dockerfile is built.
No Dockerfile	Railpack detects the language and framework and builds an image.

The first line of the build log names the builder. To build a project that has a Dockerfile with Railpack instead, rename the file or exclude it in .freepodignore.

Railpack

Railpack detects the language from the project's files, installs dependencies, runs the build step and sets a start command. See the Railpack documentation for supported languages and their configuration.

Language guides:

• Node.js
• Python
• Go

Start command

Railpack infers the start command. To set it explicitly, add a Procfile to the project root with a web entry:

Procfile

web: node server.js

The command must start a server on 0.0.0.0:$PORT. See Runtime contract.

Build-time variables

Variables set with freepod var are available to the running container only, not during the build. A build that reads environment variables gets them from one of these:

• railpack.json in the project root. Variables declared under a step are set in that step's environment:

  railpack.json

  {
    "$schema": "https://schema.railpack.com",
    "steps": { "build": { "variables": { "SIMPLE_MODE": "true" } } }
  }

  A top-level variables or env object has no effect.

• Dotenv files read by the project's own tooling, such as .env.production for Vite or Next.js. They are uploaded with the project unless .gitignore excludes them. .env.local and .env.*.local are never uploaded.

Both are committed to the repository and end up in the image. There is no mechanism for build-time secrets.

Dockerfile

When the project root contains a Dockerfile:

• Procfile and railpack.json are ignored.
• The image must still serve HTTP on 0.0.0.0:$PORT. The build log warns if the image's EXPOSE ports do not include the platform's port.
• The Dockerfile frontend is fixed by the platform. A # syntax= directive has no effect.
• RUN --security=insecure and RUN --network=host are not available.
• Base images are pulled from the registry the Dockerfile names. Anonymous pulls from Docker Hub are subject to its rate limits.
• Build arguments use the ARG defaults in the Dockerfile; freepod deploy does not pass build arguments.

What is uploaded

The project directory, minus:

1. .git/, always;
2. files matched by .gitignore files, unless freepod deploy --no-gitignore is used;
3. these defaults: node_modules/, .venv/, venv/, __pycache__/, *.pyc, .pytest_cache/, target/, dist/, build/, .DS_Store, *.swp, .env.local, .env.*.local;
4. files matched by .freepodignore in the project root.

.freepodignore uses .gitignore syntax and is applied last, so a ! pattern in it can re-include a file excluded by the earlier rules. The negation must name the path, for example !build/static/, and a file inside a directory excluded with a trailing slash cannot be re-included; exclude build/* instead of build/ to allow exceptions.

Limits

	Limit
Upload size, compressed	100 MB
Build duration	1 hour
Build resources	2 vCPU, 6 GiB memory
Architecture	linux/amd64

A build may wait in a queue before it starts. Image layers are cached per account, so later builds reuse unchanged layers.

Listing builds

freepod builds          # latest 20
freepod builds --all

The build the deployment is running is marked with *.