SDN-5342: Signer username validation

[pperiyasamy]

In CNO we have an approver that signs certs automatically, without checking any identity information, so this PR enhances the signer to check on CSR's user name that is populated by API server upon receiving CSR request from the nodes. So it's sufficient to verify the user name before signing the CSR.

It also adds required unit tests to test signer controller, it needed to change from using kubernetes.Clientset to cnoclient.Client for accessing CSR's UpdateApproval API. This needs to be tested on OCP cluster.

cc @kyrtapz @trozet @jcaamano

[openshift-ci-robot]

@pperiyasamy: This pull request references SDN-5342 which is a valid jira issue.

In response to this:

In CNO we have an approver that signs certs automatically, without checking any identity information, so this PR enhances the signer to check on CSR's user name that is populated by API server upon receiving CSR request from the nodes. So it's sufficient to verify the user name before signing the CSR.

It also adds required unit tests to test signer controller, it needed to change from using kubernetes.Clientset to cnoclient.Client for accessing CSR's UpdateApproval API. This needs to be tested on OCP cluster.

cc @kyrtapz @trozet @jcaamano

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[pperiyasamy]

/retest

[pperiyasamy]

/assign @kyrtapz @trozet @jcaamano

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: pperiyasamy
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[pperiyasamy]

/retest

[openshift-ci]

@pperiyasamy: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/e2e-aws-ovn-single-node	123242b	link	false	/test e2e-aws-ovn-single-node
ci/prow/e2e-vsphere-ovn-dualstack-primaryv6	123242b	link	false	/test e2e-vsphere-ovn-dualstack-primaryv6
ci/prow/security	123242b	link	false	/test security
ci/prow/okd-scos-e2e-aws-ovn	123242b	link	false	/test okd-scos-e2e-aws-ovn
ci/prow/e2e-aws-hypershift-ovn-kubevirt	123242b	link	false	/test e2e-aws-hypershift-ovn-kubevirt

Full PR test history. Your PR dashboard.

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