validate DNS Service IP to be a .10 IP belonging to Service CIDR

[nawazkh]

What type of PR is this?
/kind bug

What this PR does / why we need it:

• This PR updates azuremanagedcontrolplane_webhook to validate DNS Service IP is a .10 IP address.
• Refer to the second point of https://learn.microsoft.com/en-us/azure/aks/configure-kubenet#create-an-aks-cluster-with-system-assigned-managed-identities

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #3824

Special notes for your reviewer:

• cherry-pick candidate

TODOs:

• squashed commits
• includes documentation
• adds unit tests

Release note:

validate DNS Service IP to be a .10 IP belonging to Service CIDR

[codecov]

Codecov Report

Patch coverage: 88.88% and project coverage change: +0.13% 🎉

Comparison is base (a0dcdea) 54.86% compared to head (05040f2) 55.00%.
Report is 12 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3826      +/-   ##
==========================================
+ Coverage   54.86%   55.00%   +0.13%     
==========================================
  Files         188      188              
  Lines       19348    19348              
==========================================
+ Hits        10615    10642      +27     
+ Misses       8151     8116      -35     
- Partials      582      590       +8     

Files Changed	Coverage Δ
api/v1beta1/azuremanagedcontrolplane_webhook.go	87.44% <88.88%> (+5.14%)	⬆️

... and 2 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[nawazkh]

/test pull-cluster-api-provider-azure-e2e

[CecileRobertMichon]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: f325954ee37993b0ba6f9cd8d2a7b3a5f21b465f

[mboersma]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mboersma

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [mboersma]

Approvers can indicate their approval by writing /approve in a comment
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[nawazkh]

This PR should have been cherry-picked. I am not sure why the CI Robot did not cherry pick ?
@CecileRobertMichon @mboersma , I am a little confused , I am sorry, should I cherry-picking this PR into two other release branches?

[CecileRobertMichon]

@nawazkh you need to add comment the cherry-pick bot commands on the PR for it to cherry-pick, the checkbox in PR description doesn't do anything, it's just a signal to maintainers/reviewers that they should consider it for cherry-pick

/cherry-pick release-1.10
/cherry-pick release-1.9

[k8s-infra-cherrypick-robot]

@CecileRobertMichon: #3826 failed to apply on top of branch "release-1.10":

Applying: validate if DNS Service IP is a .10 IP
Using index info to reconstruct a base tree...
M	api/v1beta1/azuremachine_default_test.go
M	api/v1beta1/azuremanagedcontrolplane_webhook.go
M	api/v1beta1/azuremanagedcontrolplane_webhook_test.go
Falling back to patching base and 3-way merge...
Auto-merging api/v1beta1/azuremanagedcontrolplane_webhook_test.go
CONFLICT (content): Merge conflict in api/v1beta1/azuremanagedcontrolplane_webhook_test.go
Auto-merging api/v1beta1/azuremanagedcontrolplane_webhook.go
Auto-merging api/v1beta1/azuremachine_default_test.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 validate if DNS Service IP is a .10 IP
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

@nawazkh you need to add comment the cherry-pick bot commands on the PR for it to cherry-pick, the checkbox in PR description doesn't do anything, it's just a signal to maintainers/reviewers that they should consider it for cherry-pick

/cherry-pick release-1.10
/cherry-pick release-1.9

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[nawazkh]

it's just a signal to maintainers/reviewers that they should consider it for cherry-pick

Noted. Thanks!

[nawazkh]

/cherry-pick release-1.9

[k8s-infra-cherrypick-robot]

@nawazkh: #3826 failed to apply on top of branch "release-1.9":

Applying: validate if DNS Service IP is a .10 IP
Using index info to reconstruct a base tree...
M	api/v1beta1/azuremachine_default_test.go
M	api/v1beta1/azuremanagedcontrolplane_webhook.go
M	api/v1beta1/azuremanagedcontrolplane_webhook_test.go
Falling back to patching base and 3-way merge...
Auto-merging api/v1beta1/azuremanagedcontrolplane_webhook_test.go
CONFLICT (content): Merge conflict in api/v1beta1/azuremanagedcontrolplane_webhook_test.go
Auto-merging api/v1beta1/azuremanagedcontrolplane_webhook.go
Auto-merging api/v1beta1/azuremachine_default_test.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 validate if DNS Service IP is a .10 IP
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherry-pick release-1.9

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[nawazkh]

Merge conflicts in creating both the cherry-picks.. 🤔 Strange.
I will manually create the PRs in a bit.

[nawazkh]

^ raised two cherry-pick PRs