feat: add lambda transformation functions target (#16507)

internal/config/lambda/event/event.go

@@ -0,0 +1,80 @@
+// Copyright (c) 2015-2023 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package event
+
+import "net/http"
+
+// Identity represents access key who caused the event.
+type Identity struct {
+	Type        string `json:"type"`
+	PrincipalID string `json:"principalId"`
+	AccessKeyID string `json:"accessKeyId"`
+}
+
+// UserRequest user request headers
+type UserRequest struct {
+	URL     string      `json:"url"`
+	Headers http.Header `json:"headers"`
+}
+
+// GetObjectContext provides the necessary details to perform
+// download of the object, and return back the processed response
+// to the server.
+type GetObjectContext struct {
+	OutputRoute string `json:"outputRoute"`
+	OutputToken string `json:"outputToken"`
+	InputS3URL  string `json:"inputS3Url"`
+}
+
+// Event represents lambda function event, this is undocumented in AWS S3. This
+// structure bases itself on this structure but there is no binding.
+//
+//	{
+//	  "xAmzRequestId": "a2871150-1df5-4dc9-ad9f-3da283ca1bf3",
+//	  "getObjectContext": {
+//	    "outputRoute": "...",
+//	    "outputToken": "...",
+//	    "inputS3Url": "<presignedURL>"
+//	  },
+//	  "configuration": { // not useful in MinIO
+//	    "accessPointArn": "...",
+//	    "supportingAccessPointArn": "...",
+//	    "payload": ""
+//	  },
+//	  "userRequest": {
+//	    "url": "...",
+//	    "headers": {
+//	      "Host": "...",
+//	      "X-Amz-Content-SHA256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+//	    }
+//	  },
+//	  "userIdentity": {
+//	    "type": "IAMUser",
+//	    "principalId": "AIDAJF5MO57RFXQCE5ZNC",
+//	    "arn": "...",
+//	    "accountId": "...",
+//	    "accessKeyId": "AKIA3WNQJCXE2DYPAU7R"
+//	  },
+//	  "protocolVersion": "1.00"
+//	}
+type Event struct {
+	ProtocolVersion  string            `json:"protocolVersion"`
+	GetObjectContext *GetObjectContext `json:"getObjectContext"`
+	UserIdentity     Identity          `json:"userIdentity"`
+	UserRequest      UserRequest       `json:"userRequest"`
+}