feat: new NGINX_RESOLVERS, NGINX_RESOLVER_VALID env config (#97)

nginx-core/Dockerfile

@@ -27,7 +27,9 @@ ENV NGINX_ACCESS_LOG="/var/log/nginx/access.log json" \
     NGINX_CORS_ORIGIN="*" \
     NGINX_CORS_METHODS="GET, OPTIONS" \
     NGINX_CORS_HEADERS="*" \
-    NGINX_CORS_MAXAGE=86400
+    NGINX_CORS_MAXAGE=86400 \
+    NGINX_RESOLVERS="127.0.0.11" \
+    NGINX_RESOLVER_VALID=10s
 
 ENV NGINX_CLIENT_MAX_BODY_SIZE=10m \
     NGINX_SENDFILE=on \

nginx-core/etc/nginx/templates/http.d/00-main.conf.template

@@ -12,7 +12,7 @@ tcp_nopush          $NGINX_TCP_NOPUSH;
 tcp_nodelay         $NGINX_TCP_NODELAY;
 
 # fix dns for docker and ssl
-resolver         127.0.0.11 ipv6=off valid=10s;
+resolver         $NGINX_RESOLVERS ipv6=off valid=$NGINX_RESOLVER_VALID;
 resolver_timeout 5s;
 #resolver         1.1.1.1 8.8.8.8 8.8.4.4 valid=60s;
 #resolver_timeout 15s;

nginx/etc/nginx/entrypoint.d/10-local-resolvers.envsh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+# if $NGINX_RESOLVERS set to local, set it to the local resolvers from /etc/resolv.conf and export it
+
+set -eu
+
+LC_ALL=C
+PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+
+# if $NGINX_RESOLVERS is not set to local, do nothing
+[ "${NGINX_RESOLVERS}" == local ] || return 0
+
+NGINX_RESOLVERS=$(awk 'BEGIN{ORS=" "} $1=="nameserver" {if ($2 ~ ":") {print "["$2"]"} else {print $2}}' /etc/resolv.conf)
+
+# remove trailing space
+NGINX_RESOLVERS="${NGINX_RESOLVERS% }"
+
+export NGINX_RESOLVERS