TKG nodes are unable to resolve hostnames with the .local domain suffix

If your domain suffix is .local, you will notice that the name resolution does not work in your TKG nodes and as a result, the TKG deployment fails. This is a known issue. In modern Linux systems, attempts to resolve hostnames that have a domain suffix that ends in .local can fail. This issue occurs because, the DNS resolver in most Linux distributions, attempts to resolve the .local domain via multi-cast DNS (mDNS), not via standard DNS servers.

Workaround:

To work around this known issue, you should add a searchDomains line with your local domain suffix at the end of the vsphere-overlay-dns-control-plane.yaml and vsphere-overlay-dns-workers.yaml files.

Example Files:

vsphere-overlay-dns-control-plane.yaml

#@ load("@ytt:overlay", "overlay")
#@ load("@ytt:data", "data")

#@overlay/match by=overlay.subset({"kind":"VSphereMachineTemplate", "metadata": {"name": data.values.CLUSTER_NAME+"-control-plane"}})
---
spec:
  template:
    spec:
      network:
        devices:
        #@overlay/match by=overlay.all, expects="1+"
        -
          #@overlay/match missing_ok=True
          nameservers: ["8.8.8.8"]
          #@overlay/match missing_ok=True
          searchDomains: ["corp.local"]

vsphere-overlay-dns-workers.yaml

#@ load("@ytt:overlay", "overlay")
#@ load("@ytt:data", "data")

#@overlay/match by=overlay.subset({"kind":"VSphereMachineTemplate", "metadata": {"name": data.values.CLUSTER_NAME+"-worker"}})
---
spec:
  template:
    spec:
      network:
        devices:
        #@overlay/match by=overlay.all, expects="1+"
        -
          #@overlay/match missing_ok=True
          nameservers: ["8.8.8.8"]
          #@overlay/match missing_ok=True
          searchDomains: ["corp.local"]

Update the nameservers and the search domain as per your environment and place the YAML files in the ~/.config/tanzu/tkg/providers/infrastructure-vsphere/ytt/ directory of your bootstrap machine.

Note: This is a workaround and it is not recommended to be used in a production environment.

Hope this information helps. If it did, feel free to share it with others. Happy learning! 🙂

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