[CUPS] Rewrite based on @zajac-grzegorz work (#218)

* [CUPS] Rewrite based on @zajac-grzegorz work

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

cups/rootfs/run.sh

@@ -1,57 +1,17 @@
 #!/usr/bin/with-contenv bashio
 
-# Create links for certificates with CUPS' expected filenames
-bashio::config.require.ssl
+ulimit -n 1048576
 
-keyfile=$(bashio::config keyfile)
-certfile=$(bashio::config certfile)
-cafile=$(bashio::config cafile)
-hostname=$(bashio::info.hostname)
-fqdn=$(hostname --fqdn)
-
-mkdir -p /data/ssl
-
-if [ $cafile != null ] && [ -e "/ssl/$cafile" ]; then
-    rm -f /data/ssl/site.crt
-    ln -s "/ssl/$cafile" /data/ssl/site.crt
-fi
-
-if bashio::config.true ssl; then
-    rm -f "/data/ssl/$fqdn.key"
-    rm -f "/data/ssl/$fqdn.crt"
-    ln -s "/ssl/$keyfile" "/data/ssl/$fqdn.key"
-    ln -s "/ssl/$certfile" "/data/ssl/$fqdn.crt"
-fi
-
-# Get all possible hostnames from configuration
-result=$(bashio::api.supervisor GET /core/api/config true || true)
-internal=$(bashio::jq "$result" '.internal_url' | cut -d'/' -f3 | cut -d':' -f1)
-external=$(bashio::jq "$result" '.external_url' | cut -d'/' -f3 | cut -d':' -f1)
-
-# Fill config file templates with runtime data
-config=$(jq --arg internal "$internal" --arg external "$external" --arg hostname "$hostname" \
-    '{ssl: .ssl, require_ssl: .require_ssl, internal: $internal, external: $external, hostname: $hostname}' \
-    /data/options.json)
-
-echo "$config" | tempio \
-    -template /usr/share/cupsd.conf.tempio \
-    -out /etc/cups/cupsd.conf
-
-echo "$config" | tempio \
-    -template /usr/share/cups-files.conf.tempio \
-    -out /etc/cups/cups-files.conf
-
-echo "$config" | tempio \
-    -template /usr/share/avahi-daemon.conf.tempio \
-    -out /etc/avahi/avahi-daemon.conf
-
-mkdir -p /data/cups
-
-# Start Avahi, wait for it to start up
-touch /var/run/avahi_configured
 until [ -e /var/run/avahi-daemon/socket ]; do
   sleep 1s
 done
 
-# Start CUPS
-/usr/sbin/cupsd -f
+bashio::log.info "Preparing directories"
+cp -v -R /etc/cups /data
+rm -v -fR /etc/cups
+
+ln -v -s /data/cups /etc/cups
+
+bashio::log.info "Starting CUPS server as CMD from S6"
+
+cupsd -f