[RFC] package etesync and its dependencies and move luci on nginx

[peter-stadler]

Maintainer: me
Compile tested: MIPS 74K, Asus RT-N16, master snapshot
Run tested: MIPS 74K, Asus RT-N16, master snapshot, run the etesync server and login to it.

Description:
I am new to contributing and I am not sure if I should split it up into more changes. Especially this proposal includes moving the luci on nginx files to the luci repository, too. See my other draft PR in luci:
openwrt/luci#2981 ([RFC] move the luci on nginx files from packages to this repository)
I would do this only if Ansuel approves it since it is his project.

You should be able to login into the admin interface at
https://routerip:44312/admin
using root both as username and as password. For production you should change thereby the password and add other user(s). You can test the android client and the web client
https://client.etesync.com/
with any user, also root. In the clients you have to set an arbitrary encryption password and the advanced setting:
https://routerip:44312.

NB: the self signed certificate is not accepted by Firefox (Chromium shows a possibility to continue “unsafe”): the admin interface and the web client will not work by default; you would have to add an exception in:
Preferences > Privacy & Security > View certificates …
The Android client allows to trust the unkown certificate (pin it in the app). Should we use acme.sh to create the ssl certificate (this needs a real domain)?

This is a first proposal and there are some points still missing:

1. Install etesync to another folder (instead of /etesync-server). What would be the canonical place?

2. Maybe add uci support and a luci app for etesync, mainly for configuring the server name; there is already a admin interface build in for user management.

3. Create a self-signed certificate and enable ssl in the etesync server section of the nginx configuration.

4. Use a real domain instead of the ip as servername to make it reachable. I am not sure how to interact with the nginx configuration. Do you have any suggestions? Would it help to make it available via uci? Or would that be a bad idea or difficult?

5. Etesync starts a uwsgi instance; how can I restart it after an update of uwsgi? Would that be a good idea at all?

6. Autostart etesync by: uwsgi --ini /etc/uwsgi/sites/etesync.ini

7. The cleanup and preserving files on remove/update is only partial, especially: How do I remove empty folders?

I appreciate other suggestions for improvement, too. See also the topic at:
https://forum.openwrt.org/t/package-etesync-and-its-dependencies/42269
I hope it is understandable what I try to do.

[peter-stadler]

I see that I will have to change at least the commit messages. When doing that, should I split up the changes then? If yes, how fine?