fix(sync): fixed skipping docker images when they already synced

[eusebiu-constantin-petu-dbk]

What type of PR is this?
bug

Which issue does this PR fix:
#1490

What does this PR do / Why do we need it:
currently docker images are downloaded every time, because comparison between remote and local is done before conversion of docker images to oci.
convert docker manifests to oci manifests before syncing, compare with local one and skip if it's already synced

If an issue # is not available please add repro steps and logs showing the issue:

Testing done on this change:

Automation added to e2e:

Will this break upgrades or downgrades?
no

Does this PR introduce any user-facing change?:

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[eusebiu-constantin-petu-dbk]

need to add tests

[codecov]

Codecov Report

Merging #1521 (40f8675) into main (aab1496) will increase coverage by 0.00%.
The diff coverage is 91.50%.

@@           Coverage Diff            @@
##             main    #1521    +/-   ##
========================================
  Coverage   91.19%   91.19%            
========================================
  Files         114      114            
  Lines       22757    22862   +105     
========================================
+ Hits        20753    20849    +96     
- Misses       1495     1501     +6     
- Partials      509      512     +3     

Impacted Files	Coverage Δ
pkg/extensions/sync/utils.go	95.33% <90.32%> (-4.67%)	⬇️
pkg/api/authz.go	96.49% <100.00%> (+0.01%)	⬆️
pkg/extensions/sync/remote.go	82.75% <100.00%> (+2.49%)	⬆️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[pmirshad]

Thank you for doing this. I was debugging the same behavior as #1490 when mirroring from Amazon ECR (on-demand). Came across your PR as I was hacking in this support.

[eusebiu-constantin-petu-dbk]

Thank you for doing this. I was debugging the same behavior as #1490 when mirroring from Amazon ECR (on-demand). Came across your PR as I was hacking in this support.

Hello @pmirshad do you want to independently test this patch?

[rchincha]

lgtm

[pmirshad]

Hello @pmirshad do you want to independently test this patch?

I had patched in your changes over the latest main and was running it for the past two days. Works as expected. Log snippet from today.

{"level":"info","repository":"alpine","reference":"3.13","goroutine":817,"caller":"zotregistry.io/zot/pkg/api/routes.go:1736","time":"2023-06-22T10:34:49.656152094Z","message":"trying to get updated image by syncing on demand"}
{"level":"info","goroutine":819,"caller":"zotregistry.io/zot/pkg/extensions/sync/service.go:433","time":"2023-06-22T10:34:49.656326359Z","message":"getting available client"}
{"level":"info","remote":"https://<ecr-endpoint>","repo":"alpine","reference":"3.13","goroutine":819,"caller":"zotregistry.io/zot/pkg/extensions/sync/service.go:244","time":"2023-06-22T10:34:49.672344378Z","message":"sync: syncing image"}
{"level":"info","image":"<ecr-endpoint>/alpine:3.13","goroutine":819,"caller":"zotregistry.io/zot/pkg/extensions/sync/service.go:418","time":"2023-06-22T10:34:50.129544448Z","message":"skipping image because it's already synced"} <<<<
{"level":"info","image":"<ecr-endpoint>/alpine:3.13","goroutine":819,"caller":"zotregistry.io/zot/pkg/extensions/sync/service.go:421","time":"2023-06-22T10:34:50.129757627Z","message":"sync: finished syncing image"}
...
{"level":"info","module":"http","clientIP":"<ip>","method":"HEAD","path":"/v2/alpine/manifests/3.13?ns=<ecr-endpoint>","statusCode":200,"latency":"0s","bodySize":0,"headers":{"Accept":["application/vnd.docker.distribution.manifest.v2+json, application/vnd.docker.distribution.manifest.list.v2+json, application/vnd.oci.image.manifest.v1+json, application/vnd.oci.image.index.v1+json, */*"],"User-Agent":["containerd/1.4.13"]},"goroutine":817,"caller":"zotregistry.io/zot/pkg/api/session.go:131","time":"2023-06-22T10:34:50.33479259Z","message":"HTTP API"}
{"level":"info","module":"http","clientIP":"<ip>","method":"GET","path":"/v2/alpine/manifests/sha256:2fefe8f7522d4db9e4a67f2efa41fcad31cd6544c21b787c5dacde72c1734563?ns=<ecr-endpoint>","statusCode":200,"latency":"0s","bodySize":405,"headers":{"Accept":["application/vnd.oci.image.manifest.v1+json, */*"],"Accept-Encoding":["gzip"],"User-Agent":["containerd/1.4.13"]},"goroutine":843,"caller":"zotregistry.io/zot/pkg/api/session.go:131","time":"2023-06-22T10:34:50.349163883Z","message":"HTTP API"}
{"level":"info","module":"http","clientIP":"<ip>","method":"GET","path":"/v2/alpine/blobs/sha256:76ae9b81aa35ceec6534c5202c06e7a207dd10b073602d0a7479d1da03422a80?ns=<ecr-endpoint>","statusCode":200,"latency":"0s","bodySize":585,"headers":{"Accept":["application/vnd.oci.image.config.v1+json, */*"],"Accept-Encoding":["gzip"],"User-Agent":["containerd/1.4.13"]},"goroutine":843,"caller":"zotregistry.io/zot/pkg/api/session.go:131","time":"2023-06-22T10:34:50.369382419Z","message":"HTTP API"}
{"level":"info","module":"http","clientIP":"<ip>","method":"GET","path":"/v2/alpine/blobs/sha256:4e9f2cdf438714c2c4533e28c6c41a89cc6c1b46cf77e54c488db30ca4f5b6f3?ns=<ecr-endpoint>","statusCode":200,"latency":"0s","bodySize":2814079,"headers":{"Accept":["application/vnd.oci.image.layer.v1.tar+gzip, */*"],"Accept-Encoding":["gzip"],"User-Agent":["containerd/1.4.13"]},"goroutine":843,"caller":"zotregistry.io/zot/pkg/api/session.go:131","time":"2023-06-22T10:34:50.406012831Z","message":"HTTP API"}

Thanks again 👍🏼