helixml / base-images

Docker Image Building and Management

This section outlines the process for building and managing Docker images within this project.

Dockerfile Best Practices:

  • Leverage Multi-Stage Builds: Employ multi-stage builds to streamline image creation, minimizing the final image size. Refer to https://docs.docker.com/develop/develop-images/multistage-build/ for detailed guidance.

    • Example:

      FROM golang:1.18-alpine AS builder
          WORKDIR /app
          COPY . .
          RUN go mod download
          RUN go build -o main .
          
          FROM alpine:latest
          WORKDIR /app
          COPY --from=builder /app/main .
          CMD ["/app/main"]
  • Minimize Image Size: Prioritize smaller image sizes by only including essential files and dependencies.

    • Example:

      FROM node:16-alpine
          WORKDIR /app
          COPY package*.json ./
          RUN npm install
          COPY . .
          CMD ["npm", "start"]
  • Use Official Base Images: Utilize official base images from Docker Hub for consistency and security.

    • Example:

      FROM nginx:latest
          COPY nginx.conf /etc/nginx/conf.d/default.conf
  • Maintain Image Layers: Organize Dockerfile instructions to minimize the number of image layers, optimizing build performance.

Building Docker Images:

  1. Navigate to the Image Directory: Change directory to the location of the Dockerfile.

  2. Build the Image: Execute the following command, replacing <image-name> with the desired image name.

    docker build -t <image-name> .

Managing Docker Images:

  • Listing Images: Display available images using:

    docker images

  • Tagging Images: Assign alternative tags to existing images using:

    docker tag <image-name> <new-image-name>

  • Pushing Images to a Registry: Push images to a Docker registry (e.g., Docker Hub) with:

    docker push <registry-name>/<image-name>:<tag>

  • Deleting Images: Remove specific images using:

    docker rmi <image-name>

  • Deleting All Images: Purge all images using:

    docker rmi $(docker images -aq)

  • Running Images as Containers: Start a container from an image with:

    docker run -d -p 80:80 <image-name>

Tips for Effective Image Management:

  • Use Image Namespaces: Employ namespaces (e.g., your username or organization) to avoid naming collisions.
  • Employ Automated Builds: Integrate continuous integration and continuous delivery (CI/CD) pipelines to automate image building and deployment.

Additional Resources:

This documentation provides a foundation for Docker image building and management within this project. For more advanced techniques or specific use cases, consult the official Docker documentation and resources.