Swagger / OpenApi

About

Swagger is a suite of tool based on the openAPI specification. It was forked and is known also know as OpenApiGenerator

Example

Swagger-UI (Console / Interactive)

Web

Auto-Generated Interactive API Documentation

• Local file

docker run -itd -v $(pwd)/target/swagger:/swagger -e SWAGGER_JSON=/swagger/jaxrs-api.json -p 8888:8080 swaggerapi/swagger-ui

• URL

docker run -itd --name console --rm -e URL="http://localhost:8080/openapi.json" -p 8888:8080 swaggerapi/swagger-ui

More custom can be passed via the environment variable

Idea

• https://www.jetbrains.com/help/idea/openapi.html

Contract first

The swagger file is created and the development takes place from it.

Swagger Editor

https://swagger.io/tools/swagger-editor/

Swagger code generation

java -cp /path/to/swagger-codegen-cli-2.2.2.jar:/path/to/vertx-swagger-codegen-1.0.0.jar io.swagger.codegen.SwaggerCodegen generate \
  -l java-vertx \
  -o path/to/destination/folder \
  -i path/to/swagger/definition \
  --group-id your.group.id \
  --artifact-id your.artifact.id

Doc

OpenAPI Generator

Generate clients, servers, and documentation from OpenAPI 2.0/3.x documents

https://openapi-generator.tech/

Code first (Swagger file creation from code)

Generate the openapi file from the code

Swagger-core (Jax-RS)

With swagger-core - Swagger Core 2.X produces OpenApi 3.0 definition files.

• Wiki
• blog

Example

Aws

From https://docs.aws.amazon.com/apigateway/latest/developerguide/simple-calc-lambda-api-swagger-definition.html

{
  "swagger": "2.0",
  "info": {
    "version": "2016-09-29T20:27:30Z",
    "title": "SimpleCalc"
  },
  "host": "t6dve4zn25.execute-api.us-west-2.amazonaws.com",
  "basePath": "/demo",
  "schemes": [
    "https"
  ],
  "paths": {
    "/": {
      "get": {
        "consumes": [
          "application/json"
        ],
        "produces": [
          "application/json"
        ],
        "parameters": [
          {
            "name": "op",
            "in": "query",
            "required": false,
            "type": "string"
          },
          {
            "name": "a",
            "in": "query",
            "required": false,
            "type": "string"
          },
          {
            "name": "b",
            "in": "query",
            "required": false,
            "type": "string"
          }
        ],
        "responses": {
          "200": {
            "description": "200 response",
            "schema": {
              "$ref": "#/definitions/Result"
            }
          }
        },
        "x-amazon-apigateway-integration": {
          "requestTemplates": {
            "application/json": "#set($inputRoot = $input.path('$'))\n{\n  \"a\" : $input.params('a'),\n  \"b\" : $input.params('b'),\n  \"op\" : \"$input.params('op')\"\n}"
          },
          "uri": "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:123456789012:function:Calc/invocations",
          "passthroughBehavior": "when_no_templates",
          "httpMethod": "POST",
          "responses": {
            "default": {
              "statusCode": "200",
              "responseTemplates": {
                "application/json": "#set($inputRoot = $input.path('$'))\n{\n  \"input\" : {\n    \"a\" : $inputRoot.a,\n    \"b\" : $inputRoot.b,\n    \"op\" : \"$inputRoot.op\"\n  },\n  \"output\" : {\n    \"c\" : $inputRoot.c\n  }\n}"
              }
            }
          },
          "type": "aws"
        }
      },
      "post": {
        "consumes": [
          "application/json"
        ],
        "produces": [
          "application/json"
        ],
        "parameters": [
          {
            "in": "body",
            "name": "Input",
            "required": true,
            "schema": {
              "$ref": "#/definitions/Input"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "200 response",
            "schema": {
              "$ref": "#/definitions/Result"
            }
          }
        },
        "x-amazon-apigateway-integration": {
          "uri": "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:123456789012:function:Calc/invocations",
          "passthroughBehavior": "when_no_match",
          "httpMethod": "POST",
          "responses": {
            "default": {
              "statusCode": "200",
              "responseTemplates": {
                "application/json": "#set($inputRoot = $input.path('$'))\n{\n  \"input\" : {\n    \"a\" : $inputRoot.a,\n    \"b\" : $inputRoot.b,\n    \"op\" : \"$inputRoot.op\"\n  },\n  \"output\" : {\n    \"c\" : $inputRoot.c\n  }\n}"
              }
            }
          },
          "type": "aws"
        }
      }
    },
    "/{a}": {
      "x-amazon-apigateway-any-method": {
        "consumes": [
          "application/json"
        ],
        "produces": [
          "application/json"
        ],
        "parameters": [
          {
            "name": "a",
            "in": "path",
            "required": true,
            "type": "string"
          }
        ],
        "responses": {
          "404": {
            "description": "404 response"
          }
        },
        "x-amazon-apigateway-integration": {
          "requestTemplates": {
            "application/json": "{\"statusCode\": 200}"
          },
          "passthroughBehavior": "when_no_match",
          "responses": {
            "default": {
              "statusCode": "404",
              "responseTemplates": {
                "application/json": "{ \"Message\" : \"Can't $context.httpMethod $context.resourcePath\" }"
              }
            }
          },
          "type": "mock"
        }
      }
    },
    "/{a}/{b}": {
      "x-amazon-apigateway-any-method": {
        "consumes": [
          "application/json"
        ],
        "produces": [
          "application/json"
        ],
        "parameters": [
          {
            "name": "a",
            "in": "path",
            "required": true,
            "type": "string"
          },
          {
            "name": "b",
            "in": "path",
            "required": true,
            "type": "string"
          }
        ],
        "responses": {
          "404": {
            "description": "404 response"
          }
        },
        "x-amazon-apigateway-integration": {
          "requestTemplates": {
            "application/json": "{\"statusCode\": 200}"
          },
          "passthroughBehavior": "when_no_match",
          "responses": {
            "default": {
              "statusCode": "404",
              "responseTemplates": {
                "application/json": "{ \"Message\" : \"Can't $context.httpMethod $context.resourcePath\" }"
              }
            }
          },
          "type": "mock"
        }
      }
    },
    "/{a}/{b}/{op}": {
      "get": {
        "consumes": [
          "application/json"
        ],
        "produces": [
          "application/json"
        ],
        "parameters": [
          {
            "name": "a",
            "in": "path",
            "required": true,
            "type": "string"
          },
          {
            "name": "b",
            "in": "path",
            "required": true,
            "type": "string"
          },
          {
            "name": "op",
            "in": "path",
            "required": true,
            "type": "string"
          }
        ],
        "responses": {
          "200": {
            "description": "200 response",
            "schema": {
              "$ref": "#/definitions/Result"
            }
          }
        },
        "x-amazon-apigateway-integration": {
          "requestTemplates": {
            "application/json": "#set($inputRoot = $input.path('$'))\n{\n  \"a\" : $input.params('a'),\n  \"b\" : $input.params('b'),\n  \"op\" : \"$input.params('op')\"\n}"
          },
          "uri": "arn:aws:apigateway:us-west-2:lambda:path/2015-03-31/functions/arn:aws:lambda:us-west-2:123456789012:function:Calc/invocations",
          "passthroughBehavior": "when_no_templates",
          "httpMethod": "POST",
          "responses": {
            "default": {
              "statusCode": "200",
              "responseTemplates": {
                "application/json": "#set($inputRoot = $input.path('$'))\n{\n  \"input\" : {\n    \"a\" : $inputRoot.a,\n    \"b\" : $inputRoot.b,\n    \"op\" : \"$inputRoot.op\"\n  },\n  \"output\" : {\n    \"c\" : $inputRoot.c\n  }\n}"
              }
            }
          },
          "type": "aws"
        }
      }
    }
  },
  "definitions": {
    "Input": {
      "type": "object",
      "properties": {
        "a": {
          "type": "number"
        },
        "b": {
          "type": "number"
        },
        "op": {
          "type": "string"
        }
      },
      "title": "Input"
    },
    "Output": {
      "type": "object",
      "properties": {
        "c": {
          "type": "number"
        }
      },
      "title": "Output"
    },
    "Result": {
      "type": "object",
      "properties": {
        "input": {
          "$ref": "#/definitions/Input"
        },
        "output": {
          "$ref": "#/definitions/Output"
        }
      },
      "title": "Result"
    }
  }
}

Documentation / Reference

• https://swagger.io/