[Driver] Enhancement for concurrency

[sushanthakumar]

What this PR does / why we need it: This PR is for enhancement for concurrency scenarios at driver side

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes # This PR fixes attach part of the issue : #1197

Special notes for your reviewer:

Any other PR(s) this PR is dependant on: https://github.com/opensds/opensds/pull/1194 (Contains some base function for concurrency handling)

Test Steps: Create multiple attachments through multiple pod creation simultaneously Verify the volume and attachments states

Release note:

[kumarashit]

The issue of concurrency happens just because there is no proper error handling? Can there be a case that: a) Volume is created and attach request is made b) Port X, is specified but the Port status is not changed from available->unavailable yet c) Another Volume created and attach request made d) It finds that Port X is still available, now there may be a race condtion e) Should we wait for the next attachment request or keep a list of available and unavailable port? May be some network lag may cause attach/detach request to fall into race condition. Just thinking...

[kumarashit]

Can you please check CI issues

[kumarashit]

@sushanthakumar Please check the CI issue

[codecov[bot]]

Codecov Report

Merging #1195 into development will decrease coverage by 0.16%. The diff coverage is 3.27%.

@@               Coverage Diff               @@
##           development    #1195      +/-   ##
===============================================
- Coverage        34.82%   34.66%   -0.17%     
===============================================
  Files               97       97              
  Lines            17622    17705      +83     
===============================================
  Hits              6137     6137              
- Misses           10614    10688      +74     
- Partials           871      880       +9

Impacted Files	Coverage Δ
contrib/drivers/huawei/oceanstor/client.go	0% <0%> (ø)	:arrow_up:
contrib/drivers/huawei/oceanstor/oceanstor.go	0% <0%> (ø)	:arrow_up:
pkg/dock/dock.go	11.8% <0%> (-1.22%)	:arrow_down:
pkg/dock/discovery/discovery.go	36.73% <0%> (+3.21%)	:arrow_up:
contrib/drivers/drivers.go	23.52% <50%> (-1.48%)	:arrow_down:
pkg/controller/fileshare/filesharecontroller.go	25% <0%> (-4.6%)	:arrow_down:
pkg/controller/volume/volumecontroller.go	16.52% <0%> (-3.24%)	:arrow_down:
pkg/api/util/db.go	35.7% <0%> (-1.29%)	:arrow_down:
osdsctl/cli/volume.go	81.81% <0%> (-0.43%)	:arrow_down:
... and 14 more