feat: Add webhook support for storage mode attachments

src/app/models/__tests__/submission.server.model.spec.ts

@@ -68,6 +68,7 @@ describe('Submission Model', () => {
           isRetryEnabled: true,
           webhookView: {
             data: {
+              attachmentDownloadUrls: {},
               formId: String(form._id),
               submissionId: String(submission._id),
               encryptedContent: MOCK_ENCRYPTED_CONTENT,
@@ -120,6 +121,7 @@ describe('Submission Model', () => {
           isRetryEnabled: false,
           webhookView: {
             data: {
+              attachmentDownloadUrls: {},
               formId: String(form._id),
               submissionId: String(submission._id),
               encryptedContent: MOCK_ENCRYPTED_CONTENT,
@@ -155,6 +157,7 @@ describe('Submission Model', () => {
           isRetryEnabled: false,
           webhookView: {
             data: {
+              attachmentDownloadUrls: {},
               formId: String(form._id),
               submissionId: String(submission._id),
               encryptedContent: MOCK_ENCRYPTED_CONTENT,
@@ -268,6 +271,7 @@ describe('Submission Model', () => {
             created: expect.any(Date),
             encryptedContent: MOCK_ENCRYPTED_CONTENT,
             verifiedContent: undefined,
+            attachmentDownloadUrls: {},
             version: 1,
           },
         })
@@ -294,6 +298,7 @@ describe('Submission Model', () => {
         // Assert
         expect(actualWebhookView).toEqual({
           data: {
+            attachmentDownloadUrls: {},
             formId: expect.any(String),
             submissionId: expect.any(String),
             created: expect.any(Date),
@@ -336,6 +341,7 @@ describe('Submission Model', () => {
         // Assert
         expect(actualWebhookView).toEqual({
           data: {
+            attachmentDownloadUrls: {},
             formId: expect.any(String),
             submissionId: expect.any(String),
             created: expect.any(Date),

src/app/models/field/attachmentField.ts

@@ -1,11 +1,6 @@
 import { Document, Schema } from 'mongoose'
 
-import {
-  AttachmentSize,
-  IAttachmentField,
-  IFormSchema,
-  ResponseMode,
-} from '../../../types'
+import { AttachmentSize, IAttachmentField, IFormSchema } from '../../../types'
 
 // Manual override since mongoose types don't have generics yet.
 interface IAttachmentFieldSchema extends IAttachmentField, Document {
@@ -24,22 +19,6 @@ const createAttachmentFieldSchema = () => {
     },
   })
 
-  // Prevent attachments from being saved on a webhooked form.
-  AttachmentFieldSchema.pre<IAttachmentFieldSchema>(
-    'validate',
-    function (next) {
-      const { webhook, responseMode } = this.parent()
-
-      if (responseMode === ResponseMode.Encrypt && webhook?.url) {
-        return next(
-          Error('Attachments are not allowed when a form has a webhook url'),
-        )
-      }
-
-      return next()
-    },
-  )
-
   return AttachmentFieldSchema
 }
 

src/app/models/submission.server.model.ts

@@ -187,13 +187,18 @@ EncryptSubmissionSchema.methods.getWebhookView = function (
   const formId = this.populated('form')
     ? String(this.form._id)
     : String(this.form)
+  const attachmentRecords = Object.fromEntries(
+    this.attachmentMetadata ?? new Map(),
+  )
+
   const webhookData: WebhookData = {
     formId,
     submissionId: String(this._id),
     encryptedContent: this.encryptedContent,
     verifiedContent: this.verifiedContent,
     version: this.version,
     created: this.created,
+    attachmentDownloadUrls: attachmentRecords,
   }
 
   return {

src/app/modules/webhook/__tests__/webhook.service.spec.ts

@@ -94,6 +94,9 @@ describe('webhook.service', () => {
       formId: MOCK_FORM_ID,
       submissionId: MOCK_SUBMISSION_ID,
       verifiedContent: 'mockVerifiedContent',
+      attachmentDownloadUrls: {
+        'some-field-id': 'https://mock.s3.url/some/s3/url/timeout=3600',
+      },
       version: 1,
     },
   }

src/app/modules/webhook/webhook.errors.ts

@@ -12,6 +12,20 @@ export class WebhookValidationError extends ApplicationError {
   }
 }
 
+/**
+ * Webhook failed to generate S3 presigned URLs for attachments
+ */
+export class WebhookFailedWithPresignedUrlGenerationError extends ApplicationError {
+  meta: {
+    originalError: unknown
+  }
+
+  constructor(error: unknown, message = 'Presigned Url Generation failed') {
+    super(message)
+    this.meta = { originalError: error }
+  }
+}
+
 /**
  * Webhook returned non-200 status, but error is not instance of AxiosError
  */

src/app/modules/webhook/webhook.service.ts

@@ -1,4 +1,5 @@
 import axios from 'axios'
+import Bluebird from 'bluebird'
 import { get } from 'lodash'
 import mongoose from 'mongoose'
 import { errAsync, okAsync, ResultAsync } from 'neverthrow'
@@ -9,6 +10,7 @@ import {
   IWebhookResponse,
   WebhookView,
 } from '../../../types'
+import { aws as AwsConfig } from '../../config/config'
 import formsgSdk from '../../config/formsg-sdk'
 import { createLoggerWithLabel } from '../../config/logger'
 import { getEncryptSubmissionModel } from '../../models/submission.server.model'
@@ -18,6 +20,7 @@ import { SubmissionNotFoundError } from '../submission/submission.errors'
 
 import {
   WebhookFailedWithAxiosError,
+  WebhookFailedWithPresignedUrlGenerationError,
   WebhookFailedWithUnknownError,
   WebhookPushToQueueError,
   WebhookValidationError,
@@ -72,10 +75,35 @@ export const saveWebhookRecord = (
   })
 }
 
+const createWebhookSubmissionView = (
+  submissionWebhookView: WebhookView,
+): Promise<WebhookView> => {
+  // Generate S3 signed urls
+  const signedUrlPromises: Record<string, Promise<string>> = {}
+  for (const key in submissionWebhookView.data.attachmentDownloadUrls) {
+    signedUrlPromises[key] = AwsConfig.s3.getSignedUrlPromise('getObject', {
+      Bucket: AwsConfig.attachmentS3Bucket,
+      Key: submissionWebhookView.data.attachmentDownloadUrls[key],
+      Expires: 60 * 60, // one hour expiry
+    })
+  }
+
+  return Bluebird.props(signedUrlPromises).then((signedUrls) => {
+    submissionWebhookView.data.attachmentDownloadUrls = signedUrls
+    return submissionWebhookView
+  })
+}
+
 export const sendWebhook = (
   webhookView: WebhookView,
   webhookUrl: string,
-): ResultAsync<IWebhookResponse, WebhookValidationError> => {
+): ResultAsync<
+  IWebhookResponse,
+  | WebhookValidationError
+  | WebhookFailedWithAxiosError
+  | WebhookFailedWithPresignedUrlGenerationError
+  | WebhookFailedWithUnknownError
+> => {
   const now = Date.now()
   const { submissionId, formId } = webhookView.data
 
@@ -104,77 +132,93 @@ export const sendWebhook = (
     return error instanceof WebhookValidationError
       ? error
       : new WebhookValidationError()
-  })
-    .andThen(() =>
-      ResultAsync.fromPromise(
-        axios.post<unknown>(webhookUrl, webhookView, {
-          headers: {
-            'X-FormSG-Signature': formsgSdk.webhooks.constructHeader({
-              epoch: now,
-              submissionId,
-              formId,
-              signature,
-            }),
-          },
-          maxRedirects: 0,
-          // Timeout after 10 seconds to allow for cold starts in receiver,
-          // e.g. Lambdas
-          timeout: 10 * 1000,
-        }),
-        (error) => {
-          logger.error({
-            message: 'Webhook POST failed',
-            meta: {
-              ...logMeta,
-              isAxiosError: axios.isAxiosError(error),
-              status: get(error, 'response.status'),
-            },
-            error,
-          })
-          if (axios.isAxiosError(error)) {
-            return new WebhookFailedWithAxiosError(error)
-          }
-          return new WebhookFailedWithUnknownError(error)
-        },
-      ),
+  }).andThen(() => {
+    return ResultAsync.fromPromise(
+      createWebhookSubmissionView(webhookView),
+      (error) => {
+        logger.error({
+          message: 'S3 attachment presigned URL generation failed',
+          meta: logMeta,
+          error,
+        })
+        return new WebhookFailedWithPresignedUrlGenerationError(error)
+      },
     )
-    .map((response) => {
-      // Capture response for logging purposes
-      logger.info({
-        message: 'Webhook POST succeeded',
-        meta: {
-          ...logMeta,
-          status: get(response, 'status'),
-        },
+      .andThen((submissionWebhookView) =>
+        ResultAsync.fromPromise(
+          axios.post<unknown>(webhookUrl, submissionWebhookView, {
+            headers: {
+              'X-FormSG-Signature': formsgSdk.webhooks.constructHeader({
+                epoch: now,
+                submissionId,
+                formId,
+                signature,
+              }),
+            },
+            maxRedirects: 0,
+            // Timeout after 10 seconds to allow for cold starts in receiver,
+            // e.g. Lambdas
+            timeout: 10 * 1000,
+          }),
+          (error) => {
+            logger.error({
+              message: 'Webhook POST failed',
+              meta: {
+                ...logMeta,
+                isAxiosError: axios.isAxiosError(error),
+                status: get(error, 'response.status'),
+              },
+              error,
+            })
+            if (axios.isAxiosError(error)) {
+              return new WebhookFailedWithAxiosError(error)
+            }
+            return new WebhookFailedWithUnknownError(error)
+          },
+        ),
+      )
+      .map((response) => {
+        // Capture response for logging purposes
+        logger.info({
+          message: 'Webhook POST succeeded',
+          meta: {
+            ...logMeta,
+            status: get(response, 'status'),
+          },
+        })
+        return {
+          signature,
+          webhookUrl,
+          response: formatWebhookResponse(response),
+        }
       })
-      return {
-        signature,
-        webhookUrl,
-        response: formatWebhookResponse(response),
-      }
-    })
-    .orElse((error) => {
-      // Webhook was not posted
-      if (error instanceof WebhookValidationError) return errAsync(error)
+      .orElse((error) => {
+        // Webhook was not posted
+        if (error instanceof WebhookValidationError) return errAsync(error)
+
+        // S3 pre-signed URL generation failed
+        if (error instanceof WebhookFailedWithPresignedUrlGenerationError)
+          return errAsync(error)
+
+        // Webhook was posted but failed
+        if (error instanceof WebhookFailedWithUnknownError) {
+          return okAsync({
+            signature,
+            webhookUrl,
+            // Not Axios error so no guarantee of having response.
+            // Hence allow formatting function to return default shape.
+            response: formatWebhookResponse(),
+          })
+        }
 
-      // Webhook was posted but failed
-      if (error instanceof WebhookFailedWithUnknownError) {
+        const axiosError = error.meta.originalError
         return okAsync({
           signature,
           webhookUrl,
-          // Not Axios error so no guarantee of having response.
-          // Hence allow formatting function to return default shape.
-          response: formatWebhookResponse(),
+          response: formatWebhookResponse(axiosError.response),
         })
-      }
-
-      const axiosError = error.meta.originalError
-      return okAsync({
-        signature,
-        webhookUrl,
-        response: formatWebhookResponse(axiosError.response),
       })
-    })
+  })
 }
 
 /**

src/public/modules/forms/admin/directiveViews/settings-form.client.view.html

@@ -379,15 +379,6 @@
             <span class="field-optional">(optional)</span>
           </label>
         </div>
-        <div
-          ng-if="doesFormContainAttachments()"
-          class="alert-custom alert-info spcp-warning"
-        >
-          <i class="bx bx-info-circle bx-md icon-spacing"></i>
-          <span class="alert-msg"
-            >Webhook is not available for forms with attachment fields.</span
-          >
-        </div>
         <div class="row feature-container webhook-feature-container">
           <div
             class="settings-save col-xs-12"
@@ -401,7 +392,7 @@
               ng-model="tempForm.webhook.url"
               placeholder="https://your-webhook.com/url"
               ng-required="false"
-              ng-disabled="isFormPublic() || doesFormContainAttachments()"
+              ng-disabled="isFormPublic()"
               autocomplete="off"
               ng-keyup="$event.keyCode === 13 && settingsForm.webhookUrl.$valid && saveWebhookUrl()"
               ng-blur="saveWebhookUrl()"

src/public/modules/forms/admin/directives/edit-form.client.directive.js

@@ -337,9 +337,8 @@ function editFormController(
 
   $scope.isStorageForm = $scope.myform.responseMode === responseModeEnum.ENCRYPT
 
-  // Disable attachment fields when we have webhooks
-  $scope.isDisabledField = function (fieldType) {
-    return fieldType.name === 'attachment' && $scope.myform.webhook.url !== ''
+  $scope.isDisabledField = function () {
+    return false
   }
 
   /**