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, 53 insertions, 36 deletions

diff --git a/data/templates/dynamic-dns/ddclient.conf.j2 b/data/templates/dynamic-dns/ddclient.conf.j2
index e8ef5ac90..6d1eb03a7 100644
--- a/data/templates/dynamic-dns/ddclient.conf.j2
+++ b/data/templates/dynamic-dns/ddclient.conf.j2
@@ -1,50 +1,67 @@
+{% macro render_config(host, address, web_options, ip_suffixes=['']) %}
+{# Address: use=if, if=ethX, usev6=ifv6, ifv6=ethX, usev6=webv6, webv6=https://v6.example.com #}
+{% for ipv in ip_suffixes %}
+use{{ ipv }}={{ address if address == 'web' else 'if' }}{{ ipv }}, \
+{%     if address == 'web' %}
+{%         if web_options.url is vyos_defined %}
+web{{ ipv }}={{ web_options.url }}, \
+{%         endif %}
+{%         if web_options.skip is vyos_defined %}
+web-skip{{ ipv }}='{{ web_options.skip }}', \
+{%         endif %}
+{%     else %}
+if{{ ipv }}={{ address }}, \
+{%     endif %}
+{% endfor %}
+{# Other service options #}
+{% for k,v in kwargs.items() %}
+{%     if v is vyos_defined %}
+{{ k }}={{ v }}{{ ',' if not loop.last }} \
+{%     endif %}
+{% endfor %}
+{# Actual hostname for the service #}
+{{ host }}
+{% endmacro %}
 ### Autogenerated by dynamic_dns.py ###
 daemon=1m
 syslog=yes
 ssl=yes
 
-{% if interface is vyos_defined %}
-{%     for iface, iface_config in interface.items() %}
-# ddclient configuration for interface "{{ iface }}"
-{%         if iface_config.use_web is vyos_defined %}
-{%             set web_skip = ", web-skip='" ~ iface_config.use_web.skip ~ "'" if iface_config.use_web.skip is vyos_defined else '' %}
-use=web, web='{{ iface_config.use_web.url }}'{{ web_skip }}
-{%         else %}
-{{ 'usev6=ifv6' if iface_config.ipv6_enable is vyos_defined else 'use=if' }}, if={{ iface }}
-{%         endif %}
+{% if address is vyos_defined %}
+{%     for address, service_cfg in address.items() %}
+{%         if service_cfg.rfc2136 is vyos_defined %}
+{%             for name, config in service_cfg.rfc2136.items() %}
+{%                 if config.description is vyos_defined %}
+# {{ config.description }}
 
-{%         if iface_config.rfc2136 is vyos_defined %}
-{%             for rfc2136, config in iface_config.rfc2136.items() %}
-{%                 for dns_record in config.record if config.record is vyos_defined %}
-# RFC2136 dynamic DNS configuration for {{ rfc2136 }}, {{ config.zone }}, {{ dns_record }}
-server={{ config.server }}
-protocol=nsupdate
-password={{ config.key }}
-ttl={{ config.ttl }}
-zone={{ config.zone }}
-{{ dns_record }}
+{%                 endif %}
+{%                 for host in config.host_name if config.host_name is vyos_defined %}
+# RFC2136 dynamic DNS configuration for {{ name }}: [{{ config.zone }}, {{ host }}]
+{# Don't append 'new-style' compliant suffix ('usev4', 'usev6', 'ifv4', 'ifv6' etc.)
+   to the properties since 'nsupdate' doesn't support that yet. #}
+{{ render_config(host, address, service_cfg.web_options,
+                 protocol='nsupdate', server=config.server, zone=config.zone,
+                 password=config.key, ttl=config.ttl) }}
 
 {%                 endfor %}
 {%             endfor %}
 {%         endif %}
+{%         if service_cfg.service is vyos_defined %}
+{%             for name, config in service_cfg.service.items() %}
+{%                 if config.description is vyos_defined %}
+# {{ config.description }}
 
-{%         if iface_config.service is vyos_defined %}
-{%             for service, config in iface_config.service.items() %}
-{%                 for dns_record in config.host_name %}
-# DynDNS provider configuration for {{ service }}, {{ dns_record }}
-protocol={{ config.protocol }},
-max-interval=28d,
-{%                     if config.login is vyos_defined %}
-login={{ config.login }},
-{%                     endif %}
-password='{{ config.password }}',
-{%                     if config.server is vyos_defined %}
-server={{ config.server }},
-{%                     endif %}
-{%                     if config.zone is vyos_defined %}
-zone={{ config.zone }},
-{%                     endif %}
-{{ dns_record }}
+{%                 endif %}
+{%                 for host in config.host_name if config.host_name is vyos_defined %}
+{%                     set ip_suffixes = ['v4', 'v6'] if config.ip_version == 'both'
+                                                      else (['v6'] if config.ip_version == 'ipv6' else ['']) %}
+# Web service dynamic DNS configuration for {{ name }}: [{{ config.protocol }}, {{ host }}]
+{# For ipv4 only setup, don't append 'new-style' compliant suffix ('usev4', 'ifv4', 'webv4' etc.)
+   to the properties and instead live through the deprecation warnings for better compatibility
+   with most ddclient protocols. #}
+{{ render_config(host, address, service_cfg.web_options, ip_suffixes,
+                 protocol=config.protocol, server=config.server, zone=config.zone,
+                 login=config.username, password=config.password) }}
 
 {%                 endfor %}
 {%             endfor %}