Server: image viewer doesn't work with public link sharing unless Gallery app is enabled

Created on 24 Aug 2019 · 1Comment · Source: nextcloud/server

I recently noticed that the image viewer does not work when external users (without a nextcloud account) view a publicly shared folder unless the gallery app is installed and enabled. Clicking on an image in the folder only prompts to download the file. I've included browser logs below. There are no relevant logs for any of the containers, only the request URL as seen in the browser logs.

The viewer works as expected if I am logged into my nextcloud instance, images open as they should.

I noticed that the links are different if I'm logged in vs if i'm viewing the link un-authenicated:
authenticated:
https://my.nextcloud.server.local/remote.php/webdav/Pictures/2019%20My%20Pictures/0A0E5842-CFF5-4FCC-BE66-CB6E4FFA037C.jpeg
un-authenticated:
https://my.nextcloud.server.local/s/4jWdPqHYoGLwQ9N/download?path=%2F&files=0A0E5842-CFF5-4FCC-BE66-CB6E4FFA037C.jpeg

If I enable the gallery app external users can view images just fine. I don't particularly like the gallery app however and much prefer the built-in viewer so I had disabled it. Is this expected behavior and is there something I can do to get a viewer working for people I share links with without a dependency on the gallery app? Any help would be appreciated.

Thanks in advance

Steps to reproduce

Disable the gallery app
Create a public link share for a directory containing pictures
Log out of nextcloud or use a private window to browse to the link un-authenticated
Click on an image file

Expected behaviour

The image should open in the now built-in image viewer

Actual behaviour

You are prompted to download the file

Server configuration

Operating system:
Ubuntu 18.04.3 LTS
Web server:
Nginx (docker)
Database:
Postgres 10 (docker)
PHP version:
php-fpm (from nextcloud:fpm which should be latest compatible version)
Nextcloud version: (see Nextcloud admin page)
Nextcloud 16.0.4

Updated from an older Nextcloud/ownCloud or fresh install:
Updated to latest every release since 14
Where did you install Nextcloud from:
nextcloud/docker repo via docker-compose
Signing status:

Signing status

No errors have been found.

List of activated apps:

App list

www-data@770f2bb3d799:~/html$ ./occ app:list
Enabled:
  - accessibility: 1.2.0
  - activity: 2.9.1
  - calendar: 1.7.0
  - cloud_federation_api: 0.2.0
  - comments: 1.6.0
  - contacts: 3.1.3
  - dav: 1.9.2
  - federatedfilesharing: 1.6.0
  - federation: 1.6.0
  - files: 1.11.0
  - files_external: 1.7.0
  - files_markdown: 2.0.6
  - files_pdfviewer: 1.5.0
  - files_rightclick: 0.15.1
  - files_sharing: 1.8.0
  - files_texteditor: 2.8.0
  - files_trashbin: 1.6.0
  - files_versions: 1.9.0
  - files_videoplayer: 1.5.0
  - firstrunwizard: 2.5.0
  - gpxedit: 0.0.11
  - gpxmotion: 0.0.9
  - gpxpod: 4.0.5
  - logreader: 2.1.0
  - lookup_server_connector: 1.4.0
  - nextcloud_announcements: 1.5.0
  - notes: 3.0.1
  - notifications: 2.4.1
  - oauth2: 1.4.2
  - onlyoffice: 2.4.0
  - password_policy: 1.6.0
  - previewgenerator: 2.1.0
  - privacy: 1.0.0
  - provisioning_api: 1.6.0
  - recommendations: 0.4.0
  - serverinfo: 1.6.0
  - sharebymail: 1.6.0
  - spreed: 6.0.4
  - support: 1.0.0
  - survey_client: 1.4.0
  - systemtags: 1.6.0
  - tasks: 0.11.1
  - theming: 1.7.0
  - twofactor_backupcodes: 1.5.0
  - twofactor_u2f: 3.0.1
  - updatenotification: 1.6.0
  - viewer: 1.1.0
  - workflowengine: 1.6.0
Disabled:
  - admin_audit
  - encryption
  - gallery
  - socialsharing_email
  - user_external
  - user_ldap

Nextcloud configuration:

Config report

www-data@770f2bb3d799:~/html$ ./occ config:list system
{
    "system": {
        "memcache.local": "\\OC\\Memcache\\APCu",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "nextcloud.wyld.space"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "overwrite.cli.url": "https:\/\/nextcloud.wyld.space",
        "dbtype": "pgsql",
        "version": "16.0.4.1",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "mail_smtpmode": "smtp",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpsecure": "ssl",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauth": 1,
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "465",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "loglevel": 2,
        "theme": "",
        "app_install_overwrite": [
            "spreed"
        ],
        "overwriteprotocol": "https"
    }
}

Are you using external storage, if yes which one: local/smb/sftp/...
No
Are you using encryption: yes/no
No
Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/...
No

Client configuration

Browser:
Firefox 68.0.2
Operating system:
Archlinux

Logs

Web server error log

Nothing of relevance

Nextcloud log (data/nextcloud.log)

Nextcloud log

Nothing of relevance

Browser log

Navigated to https://my.nextcloud.server.local/s/4jWdPqHYoGLwQ9N
The resource from “https://my.nextcloud.server.local/login” was blocked due to MIME type (“text/html”) mismatch (X-Content-Type-Options: nosniff).
4jWdPqHYoGLwQ9N
JQMIGRATE: Migrate is installed, version 1.4.1 main.js:278:531
The escapeHTML library is deprecated! It will be removed in nextcloud 19. 2 main.js:750:58
The humanFileSize library is deprecated! It will be removed in nextcloud 19. 2 main.js:750:58
The humanFileSize library is deprecated! It will be removed in nextcloud 19. main.js:750:58
The humanFileSize library is deprecated! It will be removed in nextcloud 19. 2 main.js:750:58
Source map error: TypeError: NetworkError when attempting to fetch resource.
Resource URL: https://my.nextcloud.server.local/core/js/dist/main.js?v=f1359c3b-1
Source Map URL: main.js.map

Navigated to https://my.nextcloud.server.local/s/4jWdPqHYoGLwQ9N/download?path=%2F&files=0A0E5842-CFF5-4FCC-BE66-CB6E4FFA037C.jpeg

0. Needs triage bug

Source