✨ Adding feature for allocating requested IP

[ksahil12]

What this PR does / why we need it:
Requirement: Allocate a specific to IPAddressClaim or IPClaim when created with special label.
Solution: During creation of IPAddressClaim, user can provide a special label i.e. ipAddress: <IP_TO_BE_REQUESTED>. Once IPAddressClaim goes for allocation logic in ip_pool_manager, we can handle the allocation of this IP based on the requestedIP and available IPs.
For a happy path scenario, when allocation is successful, we will create IPAddress with the same IP and update IPPool index with the allocated IP.
For a scenario where user has requested an IP which does not belong to range or not available, we can patch IPAddressClaim CR with the error mentioning the same.

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 #969

[metal3-io-bot]

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[metal3-io-bot]

Hi @ksahil12. Thanks for your PR.

I'm waiting for a metal3-io member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[tuminoid]

/ok-to-test
/cc @kashifest @peppi-lotta @adilGhaffarDev

[peppi-lotta]

I tested a situation where pools preAllocations are:

Pre Allocations:
  test1:  192.168.0.12
  test2:  192.168.0.15
  test3:  192.168.0.17

and I the applied an IPClaim:

apiVersion: ipam.metal3.io/v1alpha1
kind: IPClaim
metadata:
  name: test2
  namespace: default
  labels:
    ipAddress: 192.168.0.20
spec:
  pool:
    name: pool1
    namespace: default

IpClaim then has error Error Message: Requested IP not available, which is not true. Could you add something like "PreAllocation and requested ip address are conflicting" or something along those lines.

Otherwise the feature seems to be working as I expected.

[peppi-lotta]

Could you also add tests for situation
One pool, with start and existing address, ipAddress label present and requested ipAddress in preAllocations with conflicting ipclaim name

One pool, with start and existing address, ipAddress label present and requested ipAddress in preAllocations with non-conflicting ipclaim name

It is important to understand how the new feature works with preAllocations as those are curretly an important part of CAPM3 upgrading.

[ksahil12]

Thanks for suggestion @peppi-lotta.
Updated the scenario. Also added test cases.

[peppi-lotta]

Please rebase your commits into one :)

[ksahil12]

@peppi-lotta updated the PR.

[peppi-lotta]

/test metal3-centos-e2e-integration-test-main metal3-ubuntu-e2e-integration-test-main

[peppi-lotta]

/lgtm
This seems to work well and as expected. Good job and thank you for contributing!

[ksahil12]

@peppi-lotta thanks for the review.
@tuminoid can you help with approvals as it's mentioned above to assign PR to you.