dns: T5144: Modernize dynamic dns operation

Apply next round of configuration tree updates to 'service dns dynamic'
with the following changes:

- Migrate `service dns dynamic interface <interface> [use-web]`
       to `service dns dynamic address <interface>`
       or `service dns dynamic address web [web-options]`
  This communicates the intent that dynamic dns IP address is detected
  in only one way - using the `<interface>` or using an external web
  request, not both.
- When using external web request, (`service dns dynamic address web`),
  external url is optional (`web-options url`). Ddclient defaults are
  used when unspecified,
- Rename all config `login` to `username` for consistency and also to
  align better with alternative ddclient backends in consideration.
- Apply global 'ipv6-enable' to per service 'ip-version: ipv6'. Selecting
  usage of IPv4 or IPv6 (or both simultaneously) is now at per service
  (protocol) level instead of global level. This allows more control on
  the ability to select IPv4 in some cases and IPv6 in some other cases
  wherever supported by the underlying ddclient protocol.
- While the IP address (and by extension, the detection mechanism) is
  global, the way it is applied to a particular ddclient protocol depends
  on whether it supports IPv4 or IPv6 or both.
- Related to the above, this also prevents generating incorrect config
  file (`ddclient.conf`) with multiple global sections leading to an
  unpredictable behavior of ddclient.
- Implement provider (protocol) specific custom tweaks whenever possible
  (e.g., `zone`, `username`, `server` are not necessary in all cases).
- Move service name from a combination of 'protocol' (with protocol
  config autodetected) and custom (with protocol config specified) to a
  single 'service' key. This allows for consisent setup of multiple
  config for the same ddclient protocol (with different options and
  credentials). This also avoid ambiguity with usual networking term
  'protocol' and ddclient specific term 'protocol' (and can change with
  a move to a different backend).
- Apply upfront XML constraints and validations consistently wherever
  applicable.
- RFC2136 specific change: Rename rfc2136 config `record` to `host-name`
  for consistency.
- Cloudflare specific change: While ddclient still supports authenticating
  with email and global auth key, skipping `username` in config will
  indicate the intent to use API token authentication (with special
  'token' literal as `username`).

1 files changed, 34 insertions, 0 deletions

diff --git a/interface-definitions/include/dns/dynamic-service-host-name-server.xml.i b/interface-definitions/include/dns/dynamic-service-host-name-server.xml.i
new file mode 100644
index 000000000..ee1af2a36
--- /dev/null
+++ b/interface-definitions/include/dns/dynamic-service-host-name-server.xml.i
@@ -0,0 +1,34 @@
+<!-- include start from dns/dynamic-service-host-name-server.xml.i -->
+<leafNode name="host-name">
+  <properties>
+    <help>Hostname to register with Dynamic DNS service</help>
+    <constraint>
+        #include <include/constraint/host-name.xml.i>
+    </constraint>
+    <constraintErrorMessage>Host-name must be alphanumeric and can contain hyphens</constraintErrorMessage>
+    <multi/>
+  </properties>
+</leafNode>
+<leafNode name="server">
+  <properties>
+    <help>Remote Dynamic DNS server to send updates to</help>
+    <valueHelp>
+      <format>ipv4</format>
+      <description>IPv4 address of the remote server</description>
+    </valueHelp>
+    <valueHelp>
+      <format>ipv6</format>
+      <description>IPv6 address of the remote server</description>
+    </valueHelp>
+    <valueHelp>
+      <format>hostname</format>
+      <description>Fully qualified domain name of the remote server</description>
+    </valueHelp>
+    <constraint>
+      <validator name="ip-address"/>
+      <validator name="fqdn"/>
+    </constraint>
+    <constraintErrorMessage>Remote server must be IP address or fully qualified domain name</constraintErrorMessage>
+  </properties>
+</leafNode>
+<!-- include end -->