[POC] Add tests ftp linux

[LukasReschke]

@icewind1991 I tried to port the FTP external storage tests to Drone but they do fail. Any idea what is going wrong here?

[mention-bot]

@LukasReschke, thanks for your PR! By analyzing the history of the files in this pull request, we identified @MorrisJobke, @Xenopathic and @oparoz to be potential reviewers.

[codecov-io]

Codecov Report

Merging #2806 into master will increase coverage by 0.01%.

@@            Coverage Diff             @@
##           master    #2806      +/-   ##
==========================================
+ Coverage   54.08%   54.09%   +0.01%     
==========================================
  Files        1304     1304              
  Lines       80542    80556      +14     
  Branches     1243     1243              
==========================================
+ Hits        43563    43580      +17     
+ Misses      36979    36976       -3

Impacted Files	Coverage Δ
apps/files_external/lib/Lib/Storage/FTP.php	0% <ø> (ø)	✅
lib/private/Files/Cache/Propagator.php	96.2% <ø> (+1.26%)	✅
lib/private/Http/Client/Client.php	98.36% <ø> (+10.36%)	✅

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 60a8a1a...f0c3250. Read the comment docs.

[MorrisJobke]

Rebased and fixed conflicts

[icewind1991]

Might be time to finally replace the backend with a more tested and maintained one (https://github.com/icewind1991/files_external_ftp)

[MorrisJobke]

Might be time to finally replace the backend with a more tested and maintained one (https://github.com/icewind1991/files_external_ftp)

Feel free to do so ;)

[LukasReschke]

Closing this for now. Can be reopened later.