[YUNIKORN-2850] Watch configmap only in yunikorn's deployed namespace

[400Ping]

What is this PR for?

Currently, Yunikorn uses configmap informer to handle configuration hot reload.

However, In current implementation informer watches all namespaces even only need to watch namespace in which yunikorn is deployed. It causes in efficient behavior when sync and cache configmap states. If there is too many unrelated configmap in other namespace cause long recovery time to list and memory presure to handle configmap caches which is redundant.

So, If we could replace configmap informer to namespace restricted one, it would improve startup / recovery time and reduce memory usage.

What type of PR is it?

• - Bug Fix
• - Improvement
• - Feature
• - Documentation
• - Hot Fix
• - Refactoring

What is the Jira issue?

https://issues.apache.org/jira/browse/YUNIKORN-2850

[400Ping]

Here is my make test results:
~/yunikorn/yunikorn-k8shim git:[YUNIKORN-2850]
make test
running unit tests
"go" clean -testcache
"go" test ./pkg/... -cover -race -tags deadlock -coverprofile="build/coverage.txt" -covermode=atomic
? github.com/apache/yunikorn-k8shim/pkg/admission/common [no test files]
github.com/apache/yunikorn-k8shim/pkg/cmd/admissioncontroller coverage: 0.0% of statements
ok github.com/apache/yunikorn-k8shim/pkg/admission 45.583s coverage: 78.0% of statements
ok github.com/apache/yunikorn-k8shim/pkg/admission/conf 4.441s coverage: 69.5% of statements
ok github.com/apache/yunikorn-k8shim/pkg/admission/metadata 13.545s coverage: 93.4% of statements
ok github.com/apache/yunikorn-k8shim/pkg/admission/pki 50.927s coverage: 69.6% of statements
ok github.com/apache/yunikorn-k8shim/pkg/cache 17.593s coverage: 82.0% of statements
ok github.com/apache/yunikorn-k8shim/pkg/cache/external 4.491s coverage: 68.3% of statements
ok github.com/apache/yunikorn-k8shim/pkg/client 9.061s coverage: 11.2% of statements
? github.com/apache/yunikorn-k8shim/pkg/common/constants [no test files]
github.com/apache/yunikorn-k8shim/pkg/cmd/schedulerplugin coverage: 0.0% of statements
github.com/apache/yunikorn-k8shim/pkg/cmd/shim coverage: 0.0% of statements
github.com/apache/yunikorn-k8shim/pkg/cmd/webtest coverage: 0.0% of statements
github.com/apache/yunikorn-k8shim/pkg/common/test coverage: 0.0% of statements
github.com/apache/yunikorn-k8shim/pkg/plugin coverage: 0.0% of statements
ok github.com/apache/yunikorn-k8shim/pkg/common 5.519s coverage: 100.0% of statements
ok github.com/apache/yunikorn-k8shim/pkg/common/events 4.315s coverage: 28.6% of statements
ok github.com/apache/yunikorn-k8shim/pkg/common/utils 8.628s coverage: 100.0% of statements
ok github.com/apache/yunikorn-k8shim/pkg/conf 5.240s coverage: 83.8% of statements
ok github.com/apache/yunikorn-k8shim/pkg/dispatcher 13.004s coverage: 82.5% of statements
ok github.com/apache/yunikorn-k8shim/pkg/locking 5.969s coverage: 100.0% of statements
ok github.com/apache/yunikorn-k8shim/pkg/log 21.850s coverage: 82.5% of statements
ok github.com/apache/yunikorn-k8shim/pkg/plugin/predicates 5.934s coverage: 83.1% of statements
ok github.com/apache/yunikorn-k8shim/pkg/plugin/support 7.255s coverage: 35.3% of statements
ok github.com/apache/yunikorn-k8shim/pkg/shim 32.819s coverage: 67.5% of statements
ok github.com/apache/yunikorn-k8shim/pkg/webtest 5.713s coverage: 77.8% of statements
"go" vet "github.com/apache/yunikorn-k8shim/pkg"...

[400Ping]

I see, I accidentally changed the imports. I will change it back now.

[pbacsko]

I don't understand this PR in its current form. Besides the test cases, there are two main changes:

1. informers.go: it's just reformatting
2. main.go: bail out if namespace = "". But even the original code passes the namespace to admission.NewInformers().

So what's the fundamental change here? What am I missing?

I also disagree with the main.go modification because that would result in an inconsistent behavior: the admission controller would crash loop if namespace == "" but the scheduler wouldn't.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 68.02%. Comparing base (e289196) to head (0c529a2).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/shim/scheduler.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #942      +/-   ##
==========================================
- Coverage   68.05%   68.02%   -0.04%     
==========================================
  Files          70       70              
  Lines        9194     9194              
==========================================
- Hits         6257     6254       -3     
- Misses       2730     2732       +2     
- Partials      207      208       +1     

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[craigcondit]

-1. You cannot scope the entire informer factory to a single namespace. This is used by all predicate logic, and must be able to read Kubernetes objects from multiple namespaces.

[400Ping]

I see, I am working on it.