go-swagger-gen

Go Swagger Generator

Go Swagger Generator is a tool to parse Golang source files and generate Swagger json.

Tool is based on go-swagger and supports everything that go-swagger supports, but allows to define responses and parameters as yaml.

Why?

Go-swagger expects separate structure for every response, but in my case we generate it dynamically in controller.

Example

// swagger:route PUT /packages/{id} Package packagePut
//
// Update package
//
// Parameters:
// id      string     in:path required "Package ID"
// content PutPackage in:body required "Update package params"
// | - name: type
// |   in: query
// |   description: Example parameter defined as yaml
// |   required: true
// |   type: string
// |   enum:
// |     - value1
// |     - value2
//
// Responses:
// 200: "OK"
// | schema:
// |   properties:
// |     data:
// |       $ref: "#/definitions/PackageGet"
// |     meta:
// |       $ref: "#/definitions/Meta"
// 404: "Package not found"
// | schema:
// |   $ref: "#/definitions/ErrorResponse"
// 422: "422 Unprocessable Entity"
// | schema:
// |   $ref: "#/definitions/ErrorResponse"
func PackagePut() http.HandlerFunc {
    ...
}

Usage

go-swagger-gen spec -m -i third_party_swagger.json -b project/cmd/http -o swagger.json --compact

Usage:
  go-swagger-gen [OPTIONS] spec [spec-OPTIONS]

generate spec file from go code

Help Options:
  -h, --help             Show this help message

[spec command options]
      -b, --base-path=   the base path to use (default: .)
      -m, --scan-models  includes models that were annotated with 'swagger:model'
          --compact      when present, doesn't prettify the the json
      -o, --output=      the file to write to
      -i, --input=       the file to use as input

Documentation

Please refer to go-swagger documentation, swagger.json section.

What is new compare to go-swagger

Parameters shortcuts

Allows to define route params in short form:

// swagger:route ...
//
// Parameters:
// <name>  <type>  in:<place>  <is-required> "<description>"

Where:

• name - parameter name
• type - any go type or struct with swagger:model annotation
• place - path/query/header/body/formData
• is-required - true/false or required (works as true)

Parameters yaml

// swagger:route ...
//
// Parameters:
// | valid swagger parameters yaml as array

Just put here normal swagger yaml, but prepend it with | symbol.

Response yaml

// swagger:route ...
//
// Responses:
// <code>: "<description>"
// | valid swagger response yaml

Where:

• code - integer response code
• description - response description

Just put here normal swagger yaml, but prepend it with | symbol.

Define string format of struct field in comment

type MyModelResponseDTO struct {
    // format: date-time
    CreatedAt string `json:"created_at"`
}

time.Time fields are string.date-time by default

type MyModelInputDTO struct {
    CreatedAt time.Time `json:"created_at"`
}

Get required fields from valid/validation struct tag

type MyModelInputDTO struct {
    //don't need to add "required" comment
    CreatedAt time.Time `json:"created_at" valid:"required"`
}

Skip private comments

type MyModelInputDTO struct {
    //technical comment, shouldn't appear as description in swagger
    // but this comment is used as description
    CreatedAt time.Time `json:"created_at" valid:"required"`
}

Better alias support

type Int64 int64

type MyModel struct {
    // min: 10
    IntField Int64 `json:"intField"`
}

Aliases in swagger.json present as native types. Therefore all validation comments work as expected for them.

(similar fix was merged to go-swagger https://github.com/go-swagger/go-swagger/pull/1087, but works slightly different)

x-go-name extension was removed

I don't want to expose internal name in swagger

Don't put unused definitions in result swagger.json

Scanner creates swagger definitions for embedded structures too, but often we don't need them.

Consider example:

type BaseModel struct {
    ...
}

// swagger:model
type MyModel struct {
    BaseModel
    ...
}

// we use only "#/definitions/MyModel" somewhere
// but BaseModel definition will also appear in swagger json

Therefore go-swagger-gen analyzes final json and removes unused definitions.