microshift: Use config.d directory for drop-in config directory

As per doc https://github.com/openshift/microshift/blob/main/docs/user/howto_config.md#drop-in-configuration-directory
it is better to use the drop in configuration directory then changing
the default one.

00-microshift-dns.yaml

@@ -0,0 +1,15 @@
+dns:
+    # baseDomain is the base domain of the cluster. All managed DNS records will
+    # be sub-domains of this base.
+
+
+    # For example, given the base domain `example.com`, router exposed
+    # domains will be formed as `*.apps.example.com` by default,
+    # and API service will have a DNS entry for `api.example.com`,
+    # as well as "api-int.example.com" for internal k8s API access.
+
+
+    # Once set, this field cannot be changed.
+    # example:
+    #   microshift.example.com
+    baseDomain: example.com

createdisk.sh

@@ -72,12 +72,11 @@ EOF
     # also in case of microshift the ports like 2222, 443, 80 ..etc need to be manually added
     # and OCP/OKD/podman bundles have it disabled by default.
     ${SSH} core@${VM_IP} -- sudo systemctl disable firewalld
-    ${SSH} core@${VM_IP} -- cat /etc/microshift/config.yaml.default > config.yaml
-    ${YQ} eval --inplace ".dns.baseDomain = \"${SNC_PRODUCT_NAME}.${BASE_DOMAIN}\""  config.yaml
-    ${SCP} config.yaml core@${VM_IP}:/home/core
-    ${SSH} core@${VM_IP} -- 'sudo mv /home/core/config.yaml /etc/microshift/config.yaml'
+    ${YQ} eval --inplace ".dns.baseDomain = \"${SNC_PRODUCT_NAME}.${BASE_DOMAIN}\""  00-microshift-dns.yaml
+    ${SCP} 00-microshift-dns.yaml core@${VM_IP}:/home/core
+    ${SSH} core@${VM_IP} -- 'sudo mv /home/core/00-microshift-dns.yaml /etc/microshift/config.d/00-microshift-dns.yaml'
     # Make sure `baseDomain` is set to crc.testing
-    ${SSH} core@${VM_IP} -- "grep '^\s\+baseDomain: ${SNC_PRODUCT_NAME}.${BASE_DOMAIN}' /etc/microshift/config.yaml"
+    ${SSH} core@${VM_IP} -- "grep '^\s\+baseDomain: ${SNC_PRODUCT_NAME}.${BASE_DOMAIN}' /etc/microshift/config.d/00-microshift-dns.yaml"
     # Remove the lvm system.device file since it have diskID and deviceName which changes
     # for different hypervisor and as per `man lvmdevices` if the file does not exist, or if lvm.conf
     # includes use_devicesfile=0, then lvm will not use a devices file.