Thin OpenSDS Feature

[Click2Cloud-Gamma]

Thin OpenSDS Features

• Only one storage backend is supported at a given time based on configure setting.
• Only functionalities supported by CSI spec are supported. These include create/delete volume, attach/detach volume, and create/delete snapshot
  *Communication between API server and dock will be through gRPC
• For Thin OpenSDS Dock will update the status in database after process completion.
• install_type parameter in opensds.conf will determine whether to install "Thin openSDS" or the OpenSDS with Controller.
  Reference document: https://docs.google.com/document/d/16zLCE1X8bNjkGoKvBpqDZaxEHZapWluQVgdvlxuR_tE/edit#

[coveralls]

Coverage decreased (-0.3%) to 30.322% when pulling c6e63fa on Click2Cloud-Gamma:thin_opensds_branch into c33b3cf on opensds:development.

[coveralls]

Coverage decreased (-0.3%) to 28.035% when pulling 9c05071 on Click2Cloud-Gamma:thin_opensds_branch into e62cde3 on opensds:development.

[xing-yang]

@leonwanghui PTAL.

[leonwanghui]

Need rebase for this PR.

[Click2Cloud-Gamma]

@leonwanghui @wisererik Please review.
Thanks.

[codecov]

Codecov Report

Merging #696 into development will decrease coverage by 0.27%.
The diff coverage is 0.78%.

@@               Coverage Diff               @@
##           development     #696      +/-   ##
===============================================
- Coverage        31.73%   31.46%   -0.28%     
===============================================
  Files               82       82              
  Lines            15017    15124     +107     
===============================================
- Hits              4766     4759       -7     
- Misses            9554     9668     +114     
  Partials           697      697

Impacted Files	Coverage Δ
pkg/api/controllers/volume.go	20.84% <0.78%> (-6.74%)	⬇️

[leonwanghui]

I suggest you can test it offline before pushing the code.

[leonwanghui]

Referenced by #854

[xing-yang]

@wisererik Currently Hotpot does not support multiple pools for the same backend. Therefore 1 pool = 1 backend. For Thin OpenSDS, it acts as a CSI plugin for one backend therefore there won't be a way to choose between different backends (or different pools). So using "thin" as an install type should not be a problem.