duckdns: add service

This container includes cron and should be easier to use than the
current duck.sh script. After a test period this should completely
replace the current ./duck/duck.sh script.

Currently uses my fork of linuxserver/docker-duckdns to include
some needed pull-requests that are pending.

Depends on SensorsIot#553 to generate .env with IOTSTACK_UID and IOTSTACK_GID

Mkdocs and material versions updated to fix layout bug.

Author: ukkopahis

.templates/duckdns/service.yml

@@ -0,0 +1,10 @@
+  duckdns:
+    container_name: duckdns
+    build: https://github.com/ukkopahis/docker-duckdns.git
+    network_mode: host
+    restart: unless-stopped
+    environment:
+      PUID: ${IOTSTACK_UID:?IOTSTACK_GID must be defined in ~/IOTstack/.env}
+      PGID: ${IOTSTACK_GID:?IOTSTACK_GID must be defined in ~/IOTstack/.env}
+      #TOKEN: define this in docker-compose.override.yml, see docs
+      #SUBDOMAIN: define this in docker-compose.override.yml, see docs

docs/Basic_setup/Accessing-your-Device-from-the-internet.md

@@ -39,7 +39,16 @@ A behind-the-router technique usually relies on sending updates according to a s
 
 > This seems to be a problem for DuckDNS which takes a beating because almost every person using it is sending an update bang-on five minutes.
 
-### DuckDNS client
+### DuckDNS container
+
+The recommended and easiest solution is to install the Duckdns docker-container
+from the menu. It includes the cron service and logs are handled by Docker.
+
+For configuration see [Containers/Duck DNS]( ../Containers/Duckdns.md).
+
+### DuckDNS client script (DEPRECATED) { #duckdns-client }
+
+!!! warning "This method is now deprecated"
 
 IOTstack provides a solution for DuckDNS. The best approach to running it is:
 

docs/Containers/Duckdns.md

@@ -0,0 +1,78 @@
+# Duck DNS
+
+Duckdns is a DNS service that provides you with a domain name you can update to
+match your dynamic IP-address.
+
+This container automates the process to update your duckdns.org IP.
+
+## References
+
+* Register an account, add your subdomain and get your token from
+  [http://www.duckdns.org/](http://www.duckdns.org/)
+* based on the linuxserver
+  [docker-duckdns](https://github.com/linuxserver/docker-duckdns) container
+
+## Configuration
+
+Create the file `~/IOTstack/docker-compose.override.yml` and place your Duckdns
+token and chosen domain name there:
+
+``` yaml title="docker-compose.override.yml"
+version: '3.6'
+services:
+  duckdns:
+    environment:
+      TOKEN: your-duckdns-token
+      SUBDOMAINS: subdomain
+```
+
+Observe that at least the initial update is successful:
+
+``` console
+$ cd ~/IOTstack
+$ docker-compose up -d duckdns
+$ docker-compose logs duckdns
+...SNIP...
+Retrieving subdomain and token from the environment variables
+log will be output to docker log
+Your IP was updated at Wed May  4 03:31:14 UTC 2022
+...SNIP...
+```
+
+If there is a problem, check that the resulting effective configuration of
+'duckdns:' looks OK:
+``` console
+$ cd ~/IOTstack && docker-compose config
+```
+
+### Domain name for the private IP
+
+!!! note inline end "Example IP:s and domains"
+
+    ``` mermaid
+    flowchart
+    I([Internet])
+    G("Router\npublic IP: 52.85.51.71\nsubdomain.duckdns.org")
+    R(Raspberry pi\nprivate IP: 192.168.0.100\nprivate_subdomain.duckdns.org)
+    I --- G --- |LAN| R
+    ```
+
+As a public DNS server, Duckdns is not meant to be used for private IPs. It's
+recommended that for resolving internal LAN IPs you use the [Pi
+Hole](Pi-hole.md) container.
+
+That said, it's possible to update Duckdns with to your LAN IP.  This may be
+convenient if you have devices that don't support mDNS (.local) and don't want
+to run Pi-hole. This is especially useful if you can't assign a static IP to
+your RPi. Add a `PRIVATE_SUBDOMAIN` variable indicating your subdomain for
+this:
+
+``` yaml title="added variable to docker-compose.override.yml"
+version: '3.6'
+services:
+  duckdns:
+    environment:
+      TOKEN: ...
+      SUBDOMAINS: ...
+      PRIVATE_SUBDOMAIN: private_subdomain
+```

mkdocs.yml

@@ -61,6 +61,7 @@ extra_javascript:
   - javascript/fix-codeblock-console-copy-button.js
 
 markdown_extensions:
+  - attr_list
   - pymdownx.highlight:
       pygments_lang_class: true
   - admonition

requirements-mkdocs.txt

@@ -6,14 +6,14 @@ Jinja2==3.0.3
 Markdown==3.3.6
 MarkupSafe==2.1.0
 mergedeep==1.3.4
-mkdocs==1.2.3
+mkdocs==1.3.0
 mkdocs-awesome-pages-plugin==2.7.0
-mkdocs-material==8.2.3
+mkdocs-material==8.2.13
 mkdocs-material-extensions==1.0.3
 mkdocs-redirects==1.0.3
 packaging==21.3
-Pygments==2.11.2
-pymdown-extensions==9.2
+Pygments==2.12.0
+pymdown-extensions==9.4
 pyparsing==3.0.7
 python-dateutil==2.8.2
 PyYAML==6.0