feat: private content (#1137)

* save images as private and serve via signed url from images.info api

* download private images to directory on export

* fix lint errors

* private s3 default, AWS.s3 module level scope, default s3 url expiry

* combine regex to one, and only replace when there are matches

* fix lint

* code not needed anymore, remove

* updates after pulling master

* revert the uploadToS3FromUrl url return

* use model gettr to compact code, rename to attachments api

* basic checking of document read permission to allow attachment viewing

* fix: Continue to upload avatars as public
fix: Allow redirect for non-private attachments

* add support for publicly shared documents

* catch errors which crash the app during zip export and user creation

* add tests

* enable AWS signature v4 for s3

* switch to use factories to build models for testing

* add isDocker flag for local serving of attachment redirect url

* fix redirect tests

Co-authored-by: Tom Moor <tom.moor@gmail.com>

server/presenters/document.js

@@ -1,24 +1,46 @@
 // @flow
 import { takeRight } from 'lodash';
-import { User, Document } from '../models';
+import { User, Document, Attachment } from '../models';
+import { getSignedImageUrl } from '../utils/s3';
 import presentUser from './user';
 
 type Options = {
   isPublic?: boolean,
 };
 
+const attachmentRegex = /!\[.*\]\(\/api\/attachments\.redirect\?id=(?<id>.*)\)/gi;
+
+// replaces attachments.redirect urls with signed/authenticated url equivalents
+async function replaceImageAttachments(text) {
+  const attachmentIds = [...text.matchAll(attachmentRegex)].map(
+    match => match.groups && match.groups.id
+  );
+
+  for (const id of attachmentIds) {
+    const attachment = await Attachment.findByPk(id);
+    const accessUrl = await getSignedImageUrl(attachment.key);
+    text = text.replace(attachment.redirectUrl, accessUrl);
+  }
+
+  return text;
+}
+
 export default async function present(document: Document, options: ?Options) {
   options = {
     isPublic: false,
     ...options,
   };
 
+  const text = options.isPublic
+    ? await replaceImageAttachments(document.text)
+    : document.text;
+
   const data = {
     id: document.id,
     url: document.url,
     urlId: document.urlId,
     title: document.title,
-    text: document.text,
+    text,
     emoji: document.emoji,
     createdAt: document.createdAt,
     createdBy: undefined,