This is an example linter that can be compiled into a plugin for golangci-lint.

To use this:

Create the Plugin From This Linter

1. Download the source code *
2. From the root project directory, run go build -buildmode=plugin plugin/example.go.
3. Copy the generated example.so file into your project or to some other known location of your choosing. **

Create a Copy of golangci-lint that Can Run with Plugins

In order to use plugins, you'll need a golangci-lint executable that can run them. The normal version of this project is built with the vendors option, which breaks plugins that have overlapping dependencies.

1. Download golangci-lint source code
2. From the projects root directory, run make vendor_free_build
3. Copy the golangci-lint executable that was created to your path, project, or other location

Configure Your Project for Linting

If you already have a linter plugin available, you can follow these steps to define it's usage in a projects .golangci.yml file. An example linter can be found at here. If you're looking for instructions on how to configure your own custom linter, they can be found further down.

1. If the project you want to lint does not have one already, copy the .golangci.yml to the root directory.
2. Adjust the yaml to appropriate linters-settings:custom entries as so:

linters-settings:
 custom:
  example:
   path: /example.so
   description: The description of the linter
   original-url: github.com/golangci/example-linter

That is all the configuration that is required to run a custom linter in your project. Custom linters are enabled by default, but abide by the same rules as other linters. If the disable all option is specified either on command line or in .golang.yml files linters:disable-all: true, custom linters will be disabled; they can be re-enabled by adding them to the linters:enable list, or providing the enabled option on the command line, golangci-lint run -Eexample.

To Create Your Own Custom Linter

Your linter must implement one or more golang.org/x/tools/go/analysis.Analyzer structs. Your project should also use go.mod. All versions of libraries that overlap golangci-lint (including replaced libraries) MUST be set to the same version as golangci-lint. You can see the versions by running go version -m golangci-lint.

You'll also need to create a go file like plugin/example.go. This MUST be in the package main, and define a variable of name AnalyzerPlugin. The AnalyzerPlugin instance MUST implement the following interface:

type AnalyzerPlugin interface {
    GetAnalyzers() []*analysis.Analyzer
}

The type of AnalyzerPlugin is not important, but is by convention type analyzerPlugin struct {}. See plugin/example.go for more info.

To build the plugin, from the root project directory, run go build -buildmode=plugin plugin/example.go. This will create a plugin *.so file that can be copied into your project or another well known location for usage in golangci-lint.

* Sorry, I haven't found a way to enable go get functionality for plugins yet. If you know how, let me know!

** Alternately, you can use the -o /path/to/location/example.so output flag to have it put it there for you.