Build from a Dockerfile

We will look for and use a Dockerfile at the service's root if it exists.

CloudStation notifies you when it's using the Dockerfile in the build process with the following message in the logs:

==========================
Using detected Dockerfile!
==========================

Custom Dockerfile Path

By default, we look for a file named Dockerfile in the root directory. If you want to use a custom filename or path, you can set a variable defining the path.

In your service variables, set a variable named CLOUDSTATION_DOCKERFILE_PATH to specify the path to the file.

For example, if your Dockerfile was called Dockerfile.origin, you would specify it like this:

CLOUDSTATION_DOCKERFILE_PATH=Dockerfile.origin

If your Dockerfile is in another directory, specify it like this:

CLOUDSTATION_DOCKERFILE_PATH=/build/Dockerfile

Use Config as Code

You can also set your custom Dockerfile path using config as code.

Using Variables at Build Time

If you need to use the environment variables that CloudStation injects at build time, which include variables that you define and CloudStation-shared variables, you must specify them in the Dockerfile using the ARG command.

For example:

# Specify the variable you need
ARG CLOUDSTATION_SERVICE_NAME
# Use the variable
RUN echo $CLOUDSTATION_SERVICE_NAME

Be sure to declare your environment variables in the stage they are required in:

FROM node

ARG CLOUDSTATION_ENVIRONMENT

Cache Mounts

CloudStation supports cache mounts in your Dockerfile in the following format:

--mount=type=cache,id=s/<service id>-<target path>,target=<target path>

Replace <service id> with the id of the service.

Target Path

Unsure of what your target path should be? Refer to the Nixpacks source code. Within the providers directory, find the file that aligns with your respective language or runtime, and check for the variable that indicates the CACHE_DIR.

Docker Compose

You can import services straight from your Docker Compose file! Just drag and drop your Compose file onto your project, and your services (and any mounted volumes) will be auto-imported as staged changes. It’s like magic, but with YAML instead of wands. 🪄

A quick heads-up: we don’t support every possible Compose config just yet (because Rome wasn’t built in a day). But don’t worry, we’re on it!

Docker Configuration

This section provides detailed information on how to configure Docker for your projects.

Introduction

Docker is a powerful tool for containerizing applications. This guide will walk you through the steps to configure Docker for your project.

Steps

1. Install Docker: Follow the official Docker installation guide to install Docker on your system.
2. Create a Dockerfile: A Dockerfile is a text document that contains all the commands to assemble an image. Here is an example:

   FROM node:14
   WORKDIR /app
   COPY . .
   RUN npm install
   CMD ["node", "index.js"]
3. Build the Docker Image: Use the following command to build your Docker image:

   docker build -t my-app .
4. Run the Docker Container: Use the following command to run your Docker container:

   docker run -p 3000:3000 my-app

Custom Dockerfile Path

By default, Docker looks for a file named Dockerfile in the root directory. If you want to use a custom filename or path, you can specify it using the -f option:

docker build -t my-app -f path/to/Dockerfile .

Using Environment Variables

If you need to use environment variables during the build process, you can specify them in the Dockerfile using the ARG command:

# Specify the variable you need
ARG MY_VARIABLE
# Use the variable
RUN echo $MY_VARIABLE

Conclusion

By following these steps, you can configure Docker for your project and take advantage of containerization to streamline your development and deployment processes.