Setting Up Docker

To run the development environment using Docker, begin by configuring your Dockerfile. This file will help in creating a Docker image tailored for the helixml/dagger environment.

Sample Dockerfile

# Set the base image to Go
FROM golang:1.18 AS builder

# Set the working directory
WORKDIR /app

# Copy go.mod and go.sum files
COPY go.mod ./
COPY go.sum ./

# Download dependencies
RUN go mod download

# Copy the source code
COPY . .

# Build the Go application
RUN go build -o dagger .

# Start a new stage from scratch
FROM alpine:latest  

WORKDIR /app

# Copy the executable from the builder image
COPY --from=builder /app/dagger .

# Command to run the binary
CMD ["./dagger"]

Building the Docker Image

To build your Docker image, navigate to the directory containing your Dockerfile and run the following command. This will create a Docker image named dagger.

docker build -t dagger .

Running the Docker Container

Once the image is created, you can run it using the following command:

docker run --rm -it dagger

This command starts the container in interactive mode (-it) and removes it after the process exits (--rm), ensuring a clean environment each time.

Development Workflow

To conveniently compile and run your Go code within the Docker container, you may want to set up a volume that maps your local code to the container.

Sample Docker Run Command with Volume

docker run --rm -it -v $(pwd):/app dagger

This command mounts the current directory ($(pwd)) to the /app directory in the container. Any changes made to the code in the local environment will be reflected inside the Docker container.

Testing Code Changes

For testing code changes without rebuilding the entire Docker image, you can leverage the interactive mode to execute commands directly inside the running container.

Opening a Shell in the Container

You can run a container with a shell to make testing easier:

docker run --rm -it -v $(pwd):/app dagger sh

Once inside the container, you can run your Go application or tests:

go run main.go

or

go test ./...

Environment Variables

To configure different settings or secrets, you can pass environment variables into the Docker container using the -e flag.

Sample Command to Pass Environment Variables

docker run --rm -it -e MY_ENV_VAR=value -v $(pwd):/app dagger

Inside the container, $MY_ENV_VAR can be accessed as needed by your Go code.

Summary

By utilizing Docker to manage your development environment, you ensure that all developers can work within a consistent architecture and package their applications using best practices from the start. This setup eliminates environment discrepancies and speeds up the development process.

Source: Information cited directly from the provided guidelines.