Support for dynamic ip ranges from urls

- Adds ipranges command to fetch ip ranges from Cloudfront and Cloudflare
- Write the ipranges file on docker start
- Support disabling ipv4 as well as ipv6 now
- Prevent disabling both

docker/rootfs/etc/s6-overlay/s6-rc.d/prepare/40-dynamic.sh

@@ -5,11 +5,9 @@ set -e
 
 log_info 'Dynamic resolvers ...'
 
-DISABLE_IPV6=$(echo "${DISABLE_IPV6:-}" | tr '[:upper:]' '[:lower:]')
-
 # Dynamically generate resolvers file, if resolver is IPv6, enclose in `[]`
 # thanks @tfmm
-if [ "$(is_true "$DISABLE_IPV6")" = '1' ]; then
+if [ "$(is_true "$NPM_DISABLE_IPV6")" = '1' ]; then
 	echo resolver "$(awk 'BEGIN{ORS=" "} $1=="nameserver" { sub(/%.*$/,"",$2); print ($2 ~ ":")? "["$2"]": $2}' /etc/resolv.conf) ipv6=off valid=10s;" > /etc/nginx/conf.d/include/resolvers.conf
 else
 	echo resolver "$(awk 'BEGIN{ORS=" "} $1=="nameserver" { sub(/%.*$/,"",$2); print ($2 ~ ":")? "["$2"]": $2}' /etc/resolv.conf) valid=10s;" > /etc/nginx/conf.d/include/resolvers.conf
@@ -17,3 +15,20 @@ fi
 
 # Fire off acme.sh wrapper script to "install" itself if required
 acme.sh -h > /dev/null 2>&1
+
+# Generate IP Ranges from online CDN services
+# continue on error, as this could be due to network errors
+# and can be attempted again with a docker restart
+rm -rf /etc/nginx/conf.d/include/ipranges.conf
+set +e
+RC=0
+if [ "$(is_true "$DEVELOPMENT")" = '1' ]; then
+	echo '# ignored in development mode' > /etc/nginx/conf.d/include/ipranges.conf
+else
+	/app/bin/ipranges > /etc/nginx/conf.d/include/ipranges.conf
+	RC=$?
+fi
+if [ "$RC" != '0' ]; then
+	log_warn 'Generation of IP Ranges file has an error. Check output of /etc/nginx/conf.d/include/ipranges.conf for more information.'
+fi
+set -e