On pod creation, if a new pod matches the SidecarSet update strategy …

[AiRanthem]

…selector, the latest revision rather than that specified in the sidecarset.spec.injectionStrategy will be injected.

Ⅰ. Describe what this PR does

When a Pod is created, the SidecarSet's Webhook will first determine through the UpdateStrategy whether the Pod is undergoing a Sidecar canary upgrade. If so, it will directly inject the latest Sidecar and skip the logic of selecting a specified revision of the SidecarSet based on the InjectionStrategy.

Ⅱ. Does this pull request fix one issue?

fixes #1539

Ⅲ. Describe how to verify it

1. create the sidecarset

   # sidecarset.yaml
   apiVersion: apps.kruise.io/v1alpha1
   kind: SidecarSet
   metadata:
     name: test-sidecarset
   spec:
     selector:
       matchLabels:
         app: sleep
     updateStrategy:
       type: RollingUpdate
       maxUnavailable: 1
       selector:
         matchLabels:
           canary: "true"
     containers:
       - name: sidecar
         image: curlimages/curl:8.8.0
         command: ["/bin/sleep", "infinity"]

2. deploy the demo app

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: sleep-canary
   spec:
     replicas: 1
     selector:
       matchLabels:
         name: sleep-canary
         app: sleep
     template:
       metadata:
         labels:
           app: sleep
           canary: "true"
           name: sleep-canary
       spec:
         terminationGracePeriodSeconds: 0
         containers:
           - name: sleep
             image: curlimages/curl:8.8.0
             command: ["/bin/sleep", "infinity"]
             imagePullPolicy: IfNotPresent
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: sleep
   spec:
     replicas: 1
     selector:
       matchLabels:
         name: sleep
     template:
       metadata:
         labels:
           name: sleep
           app: sleep
       spec:
         terminationGracePeriodSeconds: 0
         containers:
           - name: sleep
             image: curlimages/curl:8.8.0
             command: ["/bin/sleep", "infinity"]
             imagePullPolicy: IfNotPresent

3. upgrade the sidecarset. because of env is changed, all pods will be skipped, nothing will happen

   # upgrade.yaml
   apiVersion: apps.kruise.io/v1alpha1
   kind: SidecarSet
   metadata:
     name: test-sidecarset
   spec:
     selector:
       matchLabels:
         app: sleep
     updateStrategy:
       type: RollingUpdate
       maxUnavailable: 1
       selector:
         matchLabels:
           canary: "true"
     containers:
       - name: sidecar
         image: curlimages/curl:8.9.0
         command: ["/bin/sleep", "infinity"]
         env:
           - name: SOME_ENV
             value: "some-value"
     injectionStrategy:
       revision:
         revisionName: test-sidecarset-7dcd95bc8f # may need to be edited based on the actual situation

4. scale both the stable and canary deployments: replicas 1 -> 2

5. view images of sidecars injected: Only the newly created canary Pod is injected with sidecar version 8.9.0.

Ⅳ. Special notes for reviews

[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 3 lines in your changes missing coverage. Please review.

Project coverage is 48.83%. Comparing base (0d0031a) to head (5fe5df1).
Report is 84 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/webhook/pod/mutating/sidecarset.go	66.66%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1689      +/-   ##
==========================================
+ Coverage   47.91%   48.83%   +0.92%     
==========================================
  Files         162      188      +26     
  Lines       23491    19298    -4193     
==========================================
- Hits        11256     9425    -1831     
+ Misses      11014     8641    -2373     
- Partials     1221     1232      +11     

Flag	Coverage Δ
unittests	48.83% <66.66%> (+0.92%)	⬆️

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[furykerry]

/lgtm

[kruise-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[furykerry]

/lgtm

[furykerry]

/lgtm

[zmberg]

/approve