Docker Mastery

Build Apps That Deploy Anywhere

Pushing Images to Docker Hub and Tagging

Key Takeaways

  • Username Namespace Requirement: Docker images must be prefixed with your DockerHub username (username/image-name) to push to your personal repositories successfully
  • Automatic Latest Tagging: When no explicit tag is provided during build or push operations, Docker automatically assigns the latest tag as the default version
  • Semantic Versioning Standards: Professional image versioning follows semantic versioning (major.minor.patch):
    • Major: Breaking changes that are not backwards compatible
    • Minor: New features that remain backwards compatible
    • Patch: Bug fixes and small improvements
  • Repository Documentation Strategy: Copy README content into DockerHub repository descriptions to provide users with setup instructions, requirements, and usage guidelines
  • Multiple Tag Management: Single images can have multiple tags (1.0.0 and latest) pointing to the same image content, enabling flexible version references
  • Version Communication: Documentation should clearly distinguish between different versions and their capabilities (e.g., version 1 vs version 2 features)
  • Public Image Accessibility: Once pushed to DockerHub, images become publicly accessible, allowing anyone to docker pull and create containers from your images
  • Documentation as Code: README files serve as executable documentation - users should be able to successfully deploy applications by following the provided instructions
  • Tag Ordering Logic: DockerHub displays tags chronologically, with most recently pushed tags appearing first, regardless of semantic version numbers