Customization for nameserver/searchDomain/ntpServer for vSphere cc mode

[ydp]

What this PR does / why we need it

We need to support officially documented ytt overlay customization in CC mode. This PR address 3 of them:

• Nameservers on vSphere (This one is just a fix, add indentation and support multiple nameserver)
• Resolve .local Domain
• Configuring NTP without DHCP Option 42

Which issue(s) this PR fixes

Part of #3616

Describe testing done for PR

Manually create CC cluster with customization.

Release note

Support customization for nameserver/searchDomain/ntpServer when creating CC based cluster on vSphere

Doc

Nameservers on vSphere

1. Enable custom-nameservers flag:
   tanzu config set features.management-cluster.custom-nameservers true
2. Add below variable in config file to customize name server on control plane and worker nodes, for example:

CONTROL_PLANE_NODE_NAMESERVERS: 10.132.7.1, 10.142.7.1
WORKER_NODE_NAMESERVERS: 10.132.7.1, 10.142.7.1

Validate whether it's set successfully, login into the control plane or worker node vm:

$ cat /etc/systemd/network/10-cloud-init-eth0.network
[Network]
DHCP=ipv4
DNS=10.132.7.1 10.142.7.1

Resolve .local Domain

Add below variable in config file to customize search domain:

CONTROL_PLANE_NODE_SEARCH_DOMAINS: eng.vmware.com, vmware.com
WORKER_NODE_SEARCH_DOMAINS: eng.vmware.com, vmware.com

Validate whether it's set successfully, login into the control plane or worker node vm:

$ cat /etc/systemd/network/10-cloud-init-eth0.network
[Network]
DHCP=ipv4
Domains=eng.vmware.com vmware.com

Configuring NTP without DHCP Option 42 (vSphere)

Add below variable in config file to customize ntp servers:

NTP_SERVERS: time.google.com

Validate whether it's set successfully, login into the control plane or worker node vm:

$ cat /etc/chrony.conf
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
# servers
server time.google.com iburst

Additional information

Special notes for your reviewer

[codecov]

Codecov Report

Merging #3617 (58456af) into main (7a3435b) will decrease coverage by 0.93%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3617      +/-   ##
==========================================
- Coverage   46.26%   45.32%   -0.94%     
==========================================
  Files         400      425      +25     
  Lines       39624    41188    +1564     
==========================================
+ Hits        18331    18668     +337     
- Misses      19605    20810    +1205     
- Partials     1688     1710      +22     

Impacted Files	Coverage Δ
addons/controllers/machine_controller.go	65.65% <0.00%> (-3.04%)	⬇️
addons/controllers/clusterbootstrap_controller.go	63.26% <0.00%> (-1.61%)	⬇️
cmd/cli/plugin/cluster/credentials_update.go	9.23% <0.00%> (ø)
cmd/cli/plugin/cluster/delete_node_pool.go	16.66% <0.00%> (ø)
cmd/cli/plugin/cluster/machinehealthcheck.go	100.00% <0.00%> (ø)
cmd/cli/plugin/cluster/main.go	0.00% <0.00%> (ø)
cmd/cli/plugin/cluster/delete.go	12.50% <0.00%> (ø)
...in/cluster/get_machinehealthcheck_control_plane.go	11.11% <0.00%> (ø)
...i/plugin/cluster/delete_machinehealthcheck_node.go	16.66% <0.00%> (ø)
cmd/cli/plugin/cluster/set_machinehealthcheck.go	23.33% <0.00%> (ø)
... and 18 more

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[wjun]

LGTM. Please rebase the codes from main branch and clear the checks failure.

[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/3617/20221012072253/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[wjun]

LGTM after rebase the codes to solve the conflicts.

[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/3617/20221014113921/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[ydp]

Rebased the code and Updated commit title to reflect it's only for vSphere.
All pipeline passed.