Coding Conventions

This document outlines a collection of guidelines, style suggestions, and tips for writing code in the different programming languages used throughout the Kubernetes project.

Code conventions

  • Bash

  • Go

    • Go Code Review Comments
    • Effective Go
    • Know and avoid Go landmines
    • Comment your code.
    • Command-line flags should use dashes, not underscores
    • Naming
      • Please consider package name when selecting an interface name, and avoid redundancy. For example, storage.Interface is better than storage.StorageInterface.
      • Do not use uppercase characters, underscores, or dashes in package names.
      • Please consider parent directory name when choosing a package name. For example, pkg/controllers/autoscaler/foo.go should say package autoscaler not package autoscalercontroller.
        • Unless there’s a good reason, the package foo line should match the name of the directory in which the .go file exists.
        • Importers can use a different name if they need to disambiguate.
      • Locks should be called lock and should never be embedded (always lock sync.Mutex). When multiple locks are present, give each lock a distinct name following Go conventions: stateLock, mapLock etc.

Testing conventions

  • All new packages and most new significant functionality must come with unit tests.
  • Significant features should come with integration and/or end-to-end.
  • Do not expect an asynchronous thing to happen immediately—do not wait for one second and expect a pod to be running. Wait and retry instead.

Directory and file conventions

  • Avoid package sprawl. Find an appropriate subdirectory for new packages.
    • Libraries with no appropriate home belong in new package subdirectories of pkg/util.
  • Avoid general utility packages. Packages called “util” are suspect. Instead, derive a name that describes your desired function. For example, the utility functions dealing with waiting for operations are in the wait package and include functionality like Poll. The full name is wait.Poll.
  • All filenames should be lowercase.
  • Go source files and directories use underscores, not dashes.
    • Package directories should generally avoid using separators as much as possible. When package names are multiple words, they usually should be in nested subdirectories.
  • Document directories and filenames should use dashes rather than underscores.
  • Go code for normal third-party dependencies is managed using go modules.
Last modified April 16, 2024: Update favicons (#285) (acbfbbf)