Code Conventions

In this section, you will find the code conventions for all kinds of code KubeVela project related. It's not necessary to learn all of them at once, but make sure you have read corresponding parts before you start to code.

• Go Code Conventions
• Bash or Script Conventions
• API Conventions
• Testing Conventions
• Directory and File Conventions
• Logging Conventions

Go Code Conventions

• Go Code Review Comments

• Effective Go

• Know and avoid Go landmines

• Comment your code.

  • Go's commenting conventions
  • If reviewers ask questions about why the code is the way it is, that's a sign that comments might be helpful.

• Command-line flags should use dashes, not underscores

• API

  • According to RFC3986, URLs are "case sensitive". KubeVela uses snake_case for API URLs.
    • e.g.: POST /v1/cloud_clusters

• Naming

  • Please consider package name when selecting an interface name, and avoid redundancy.

    • e.g.: 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.

    • so 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.

Bash or Script Conventions

• https://google.github.io/styleguide/shell.xml

• Ensure that build, release, test, and cluster-management scripts run on macOS

API Conventions

• KubeVela follows the Kubernetes conventions

  • API changes

  • API conventions

Testing Conventions

• All new packages and most new significant functionality must come with unit tests

• Table-driven tests are preferred for testing multiple scenarios/inputs; for example, see TestNamespaceAuthorization

• Unit tests must pass on macOS and Windows platforms - if you use Linux specific features, your test case must either be skipped on windows or compiled out (skipped is better when running Linux specific commands, compiled out is required when your code does not compile on Windows).

• Avoid waiting for a short amount of time (or without waiting) and expect an asynchronous thing to happen (e.g. wait for 1 seconds and expect a Pod to be running). Wait and retry instead.

• Significant features should come with integration (test/integration) and/or end-to-end (e2e/) tests.

• Including new vela cli commands and major features of existing commands

Please refer to the principle of test for more details.

Directory and file Conventions

• Avoid package sprawl. Find an appropriate subdirectory for new packages.

  • Libraries with no more 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. So 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 packages are multiple words, they usually should be in nested subdirectories).

• Document directories and filenames should use dashes rather than underscores

• Contrived examples that illustrate system features belong in /docs/user-guide or /docs/admin, depending on whether it is a feature primarily intended for users that deploy applications or cluster administrators, respectively. Actual application examples belong in /examples.

  • Examples should also illustrate best practices for configuration and using the system

• Third-party code

  • Go code for normal third-party dependencies is managed using go modules

  • Other third-party code belongs in /third_party

    • forked third party Go code goes in /third_party/forked
    • forked golang stdlib code goes in /third_party/forked/golang

  • Third-party code must include licenses

  • This includes modified third-party code and excerpts, as well

Logging Conventions

Structured logging

We recommend using klog.InfoS to structure the log. The msg argument need start from a capital letter. and name arguments should always use lowerCamelCase.

// func InfoS(msg string, keysAndValues ...interface{})
klog.InfoS("Reconcile traitDefinition", "traitDefinition", klog.KRef(req.Namespace, req.Name))
// output:
// I0605 10:10:57.308074   22276 traitdefinition_controller.go:59] "Reconcile traitDefinition" traitDefinition="vela-system/expose"

Use klog.KObj and klog.KRef for Kubernetes objects

klog.KObj and klog.KRef can unify the output of kubernetes object.

// KObj is used to create ObjectRef when logging information about Kubernetes objects
klog.InfoS("Start to reconcile", "appDeployment", klog.KObj(appDeployment))
// KRef is used to create ObjectRef when logging information about Kubernetes objects without access to metav1.Object
klog.InfoS("Reconcile application", "application", klog.KRef(req.Namespace, req.Name))

Logging Level

This file contains KubeVela's log level, you can set the log level by klog.V(level).

// you can use klog.V(common.LogDebug) to print debug log
klog.V(common.LogDebug).InfoS("Successfully applied components", "workloads", len(workloads))

Looking for more details in Structured Logging Guide.

Linting and formatting

To ensure consistency across the Go codebase, we require all code to pass a number of linter checks.

To run all linters, use the reviewable Makefile target:

make reviewable

The command will clean code along with some lint checks. Please remember to check in all changes after that.