使用 API Gateway API 访问 Lambda 中的二进制文件

以下 OpenAPI 示例展示了如何通过 API Gateway API 访问 AWS Lambda 中的二进制文件。此 API 公开了用于下载和上传指定图像文件的 GET /lambda?key={file-name} 和 PUT /lambda?key={file-name} 方法。GET 方法按照所提供的映射模板，在一个 200 OK 响应中返回 Base64 编码字符串形式的图像文件作为 JSON 输出的一部分。PUT 方法将原始二进制 blob 作为输入，并返回一个负载为空的 200 OK 响应。

您创建 API 调用的 Lambda 函数，该函数必须返回 Content-Type 标头为 application/json 的 base64 编码字符串。

用于访问 Lambda 中图像的示例 API 的 OpenAPI 文件

以下 OpenAPI 文件显示了一个 API 示例，阐明了如何从 Lambda 下载图像文件以及如何将图像文件上传到 Lambda。

OpenAPI 3.0

{
   "openapi": "3.0.0",
   "info": {
      "version": "2016-10-21T17:26:28Z",
      "title": "ApiName"
   },
   "paths": {
      "/lambda": {
         "get": {
            "parameters": [
               {
                  "name": "key",
                  "in": "query",
                  "required": false,
                  "schema": {
                     "type": "string"
                  }
               }
            ],
            "responses": {
               "200": {
                  "description": "200 response",
                  "content": {
                     "application/json": {
                        "schema": {
                           "$ref": "#/components/schemas/Empty"
                        }
                     }
                  }
               },
               "500": {
                  "description": "500 response"
               }
            },
            "x-amazon-apigateway-integration": {
               "uri": "arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-1:123456789012:function:image/invocations",
               "type": "AWS",
               "credentials": "arn:aws:iam::123456789012:role/Lambda",
               "httpMethod": "POST",
               "requestTemplates": {
                  "application/json": "{\n   \"imageKey\": \"$input.params('key')\"\n}"
               },
               "responses": {
                  "default": {
                     "statusCode": "500"
                  },
                  "2\\d{2}": {
                     "statusCode": "200",
                     "responseTemplates": {
                        "application/json": "{\n   \"image\": \"$input.body\"\n}"
                     }
                  }
               }
            }
         },
         "put": {
            "parameters": [
               {
                  "name": "key",
                  "in": "query",
                  "required": false,
                  "schema": {
                     "type": "string"
                  }
               }
            ],
            "responses": {
               "200": {
                  "description": "200 response",
                  "content": {
                     "application/json": {
                        "schema": {
                           "$ref": "#/components/schemas/Empty"
                        }
                     },
                     "application/octet-stream": {
                        "schema": {
                           "$ref": "#/components/schemas/Empty"
                        }
                     }
                  }
               },
               "500": {
                  "description": "500 response"
               }
            },
            "x-amazon-apigateway-integration": {
               "uri": "arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-1:123456789012:function:image/invocations",
               "type": "AWS",
               "credentials": "arn:aws:iam::123456789012:role/Lambda",
               "httpMethod": "POST",
               "contentHandling": "CONVERT_TO_TEXT",
               "requestTemplates": {
                  "application/json": "{\n   \"imageKey\": \"$input.params('key')\", \"image\": \"$input.body\"\n}"
               },
               "responses": {
                  "default": {
                     "statusCode": "500"
                  },
                  "2\\d{2}": {
                     "statusCode": "200"
                  }
               }
            }
         }
      }
   },
   "x-amazon-apigateway-binary-media-types": [
      "application/octet-stream",
      "image/jpeg"
   ],
   "servers": [
      {
         "url": "https://abcdefghi.execute-api.us-east-1.amazonaws.com/{basePath}",
         "variables": {
            "basePath": {
              "default": "/v1"
            }
         }
      }
   ],
   "components": {
      "schemas": {
         "Empty": {
            "type": "object",
            "title": "Empty Schema"
         }
      }
   }
}

OpenAPI 2.0

{
  "swagger": "2.0",
  "info": {
    "version": "2016-10-21T17:26:28Z",
    "title": "ApiName"
  },
  "host": "abcdefghi.execute-api.us-east-1.amazonaws.com",
  "basePath": "/v1",
  "schemes": [
    "https"
  ],
  "paths": {
    "/lambda": {
      "get": {
        "produces": [
          "application/json"
        ],
        "parameters": [
          {
            "name": "key",
            "in": "query",
            "required": false,
            "type": "string"
          }
        ],
        "responses": {
          "200": {
            "description": "200 response",
            "schema": {
              "$ref": "#/definitions/Empty"
            }
          },
          "500": {
            "description": "500 response"
          }
        },
        "x-amazon-apigateway-integration": {
          "uri": "arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-1:123456789012:function:image/invocations",
          "type": "AWS",
          "credentials": "arn:aws:iam::123456789012:role/Lambda",
          "httpMethod": "POST",
          "requestTemplates": {
            "application/json": "{\n   \"imageKey\": \"$input.params('key')\"\n}"
          },
          "responses": {
            "default": {
              "statusCode": "500"
            },
            "2\\d{2}": {
              "statusCode": "200",
              "responseTemplates": {
                "application/json": "{\n   \"image\": \"$input.body\"\n}"
              }
            }
          }
        }
      },
      "put": {
        "produces": [
          "application/json", "application/octet-stream"
        ],
        "parameters": [
          {
            "name": "key",
            "in": "query",
            "required": false,
            "type": "string"
          }
        ],
        "responses": {
          "200": {
            "description": "200 response",
            "schema": {
              "$ref": "#/definitions/Empty"
            }
          },
          "500": {
            "description": "500 response"
          }
        },
        "x-amazon-apigateway-integration": {
          "uri": "arn:aws:apigateway:us-east-1:lambda:path/2015-03-31/functions/arn:aws:lambda:us-east-1:123456789012:function:image/invocations",
          "type": "AWS",
          "credentials": "arn:aws:iam::123456789012:role/Lambda",
          "httpMethod": "POST",
          "contentHandling" : "CONVERT_TO_TEXT",
          "requestTemplates": {
            "application/json": "{\n   \"imageKey\": \"$input.params('key')\", \"image\": \"$input.body\"\n}"
          },
          "responses": {
            "default": {
              "statusCode": "500"
            },
            "2\\d{2}": {
              "statusCode": "200"
            }
          }
        }
      }
    }
  },
  "x-amazon-apigateway-binary-media-types" : ["application/octet-stream", "image/jpeg"],
  "definitions": {
    "Empty": {
      "type": "object",
      "title": "Empty Schema"
    }
  }
}

从 Lambda 下载图像

从 Lambda 下载二进制 blob 形式的图像文件 (image.jpg)：

GET /v1/lambda?key=image.jpg HTTP/1.1
Host: abcdefghi.execute-api.us-east-1.amazonaws.com
Content-Type: application/json
Accept: application/octet-stream

成功响应如下所示：

200 OK HTTP/1.1

[raw bytes]

从 Lambda 下载 Base64 编码字符串（格式化为 JSON 属性）形式的图像文件 (image.jpg)：

GET /v1/lambda?key=image.jpg HTTP/1.1
Host: abcdefghi.execute-api.us-east-1.amazonaws.com
Content-Type: application/json
Accept: application/json

成功响应如下所示：

200 OK HTTP/1.1

{
  "image": "W3JhdyBieXRlc10="
}

将图像上传到 Lambda

将二进制 blob 形式的图像文件 (image.jpg) 上传到 Lambda：

PUT /v1/lambda?key=image.jpg HTTP/1.1
Host: abcdefghi.execute-api.us-east-1.amazonaws.com
Content-Type: application/octet-stream
Accept: application/json

[raw bytes]

成功响应如下所示：

200 OK            

将 Base64 编码字符串形式的图像文件 (image.jpg) 上传到 Lambda：

PUT /v1/lambda?key=image.jpg HTTP/1.1
Host: abcdefghi.execute-api.us-east-1.amazonaws.com
Content-Type: application/json
Accept: application/json

W3JhdyBieXRlc10=

成功响应如下所示：

200 OK