Kobo sync error on Docker using https reverse proxy

[luke-70it]

I configured Calibre Web as a Docker container. Inside my home network it uses default 8083 port in plain http, but I use swag Docker container to be able to access all my dockers using https (on standard 443 port) via duckdns and letsencrypt.
kobo glo can't sync

To Reproduce
Steps to reproduce the behavior:

1. I enabled "Enable Kobo sync" and "Proxy unknown requests to Kobo Store" in Feature Configuration
2. I changed "Server external port" to 443
3. I added to Kobo eReader.conf file the line: api_endpoint=https://..duckdns.org/kobo/<api_key>
4. I restarted both Calibre Web Docker and Kobo Glo

I checked my Kobo eReader.conf and I saw that a number of entries were added:
image_host=http://..duckdns.org
image_url_quality_template=http://..duckdns.org/kobo/<api_key>/{Quality}/isGreyscale/image.jpg
image_url_template=http://..duckdns.org/kobo/<api_key>/{ImageId}/{width}/{height}/false/image.jpg

These 3 parameters doesn't use https and the links result inaccessible. Probably this is the problem.

If I configure both Calibre Web and Kobo Glo to use plain http protocol and standard 8083 port kobo sync work flawless, but it would be nice if I can use ssl encryption

Environment:

• OS: Openmediavault 5.5.17.3 and Docker 20.10.0-3

Platform Linux 5.9.0-0.bpo.2-amd64 #1 SMP Debian 5.9.6-1~bpo10+1 (2020-11-19) x86_64 x86_64
Python 3.6.9 (default, Oct 8 2020, 12:12:24) [GCC 8.4.0]
Calibre_Web 0.6.9 - a9c0bcb - 2020-09-27T07:15:03+02:00
WebServer Gevent 20.5.2
Flask 1.1.2
Flask_Login 0.5.0
Flask_Principal 0.4.0
Werkzeug 1.0.1
Babel 2.8.1
Jinja2 2.11.2
Requests 2.25.0
SqlAlchemy 1.3.20
pySqlite 2.6.0
SQLite 3.22.0
iso639 0.4.5
pytz 2020.4
Unidecode installed
Flask_SimpleLDAP installed
python_LDAP 3.2.0
Goodreads installed
Jsonschema 3.2.0
flask_dance 3.0.0
Image Magick ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
PyPdf v1.26.0
lxml v4.5.2.0
Wand 0.5.9
Pillow v7.1.2
Comic_API 2.1.1
ebook converter not installed
unrar UNRAR 5.50 freeware Copyright (c) 1993-2017 Alexander Roshal
kepubify kepubify v3.1.6

[OzzieIsaacs]

Please try to edit the eReader.conf file again and change the http to https then it should work.
There is not much I can do from this side regarding this, the texts are added by the kobo reader itself. I dont know why it added http links instead of https.

[luke-70it]

Unfortunately after kobo reboot these urls are automatically changed to http :(
If these parameters are compiled automatically by the ereader itself there is nothing to do, and I don't think I can open a ticket to kobo... ;)

Thank you for your reply and for this great software!