docs: add example Dockerfile

README.md

@@ -187,9 +187,11 @@ If you want to provide an additional IPv6 address as myip6 parameter, the myip p
 Use a webserver as a proxy to handle SSL and/or multiple listen addresses and ports. DynDNS.com provides HTTP on port 80 and 8245 and HTTPS on port 443.
 
 
-### Init scripts
+### Startup
 
-The [Debian 6 init.d script](init.d/debian-6-dyndnsd) assumes that dyndnsd.rb is installed into the system ruby (no RVM support) and the config.yaml is at /opt/dyndnsd/config.yaml. Modify to your needs.
+There is a [Dockerfile](docs/Dockerfile) that can be used to build a Docker image for running dyndnsd.rb.
+
+The [Debian 6 init.d script](docs/debian-6-init-dyndnsd) assumes that dyndnsd.rb is installed into the system ruby (no RVM support) and the config.yaml is at /opt/dyndnsd/config.yaml. Modify to your needs.
 
 
 ### Monitoring

docs/Dockerfile

@@ -0,0 +1,15 @@
+FROM alpine:3.12
+
+EXPOSE 5353 8080
+
+ENV VERSION=3.0.0
+
+RUN apk --no-cache add openssl ca-certificates && \
+    apk --no-cache add ruby ruby-etc ruby-io-console ruby-json ruby-webrick && \
+    apk --no-cache add --virtual .build-deps ruby-dev build-base tzdata && \
+    gem install --no-document dyndnsd -v ${VERSION} && \
+    # set timezone to Berlin
+    cp /usr/share/zoneinfo/Europe/Berlin /etc/localtime && \
+    apk del .build-deps
+
+ENTRYPOINT ["dyndnsd", "/etc/dyndnsd/config.yml"]