Implemented NETWORK_ACCESS (squash commit)

Dockerfile

@@ -24,6 +24,8 @@ RUN wget https://github.com/jwilder/docker-gen/releases/download/$DOCKER_GEN_VER
  && tar -C /usr/local/bin -xvzf docker-gen-linux-amd64-$DOCKER_GEN_VERSION.tar.gz \
  && rm /docker-gen-linux-amd64-$DOCKER_GEN_VERSION.tar.gz
 
+COPY network_internal.conf /etc/nginx/
+
 COPY . /app/
 WORKDIR /app/
 

README.md

@@ -95,6 +95,25 @@ $ docker network connect my-other-network my-nginx-proxy
 
 In this example, the `my-nginx-proxy` container will be connected to `my-network` and `my-other-network` and will be able to proxy to other containers attached to those networks.
 
+### Internet vs. Local Network Access
+
+If you allow traffic from the public internet to access your `nginx-proxy` container, you may want to restrict some containers to the internal network only, so they cannot be accessed from the public internet.  On containers that should be restricted to the internal network, you should set the environment variable `NETWORK_ACCESS=internal`.  By default, the *internal* network is defined as `127.0.0.0/8, 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16`.  To change the list of networks considered internal, mount a file on the `nginx-proxy` at `/etc/nginx/network_internal.conf` with these contents, edited to suit your needs:
+
+```
+# These networks are considered "internal"
+allow 127.0.0.0/8;
+allow 10.0.0.0/8;
+allow 192.168.0.0/16;
+allow 172.16.0.0/12;
+
+# Traffic from all other networks will be rejected
+deny all;
+```
+
+When internal-only access is enabled, external clients with be denied with an `HTTP 403 Forbidden`
+
+> If there is a load-balancer / reverse proxy in front of `nginx-proxy` that hides the client IP (example: AWS Application/Elastic Load Balancer), you will need to use the nginx `realip` module (already installed) to extract the client's IP from the HTTP request headers.  Please see the [nginx realip module configuration](http://nginx.org/en/docs/http/ngx_http_realip_module.html) for more details.  This configuration can be added to a new config file and mounted in `/etc/nginx/conf.d/`.
+
 ### SSL Backends
 
 If you would like the reverse proxy to connect to your backend using HTTPS instead of HTTP, set `VIRTUAL_PROTO=https` on the backend container.

network_internal.conf

@@ -0,0 +1,6 @@
+# Only allow traffic from internal clients
+allow 127.0.0.0/8;
+allow 10.0.0.0/8;
+allow 192.168.0.0/16;
+allow 172.16.0.0/12;
+deny all;

nginx.tmpl

@@ -147,6 +147,12 @@ upstream {{ $upstream_name }} {
 {{/* Get the VIRTUAL_PROTO defined by containers w/ the same vhost, falling back to "http" */}}
 {{ $proto := trim (or (first (groupByKeys $containers "Env.VIRTUAL_PROTO")) "http") }}
 
+{{/* Get the NETWORK_ACCESS defined by containers w/ the same vhost, falling back to "external" */}}
+{{ $network_tag := or (first (groupByKeys $containers "Env.NETWORK_ACCESS")) "external" }}
+
+{{/* Get the NETWORK_ACCESS defined by containers w/ the same vhost, falling back to "external" */}}
+{{ $network_tag := or (first (groupByKeys $containers "Env.NETWORK_ACCESS")) "external" }}
+
 {{/* Get the HTTPS_METHOD defined by containers w/ the same vhost, falling back to "redirect" */}}
 {{ $https_method := or (first (groupByKeys $containers "Env.HTTPS_METHOD")) "redirect" }}
 
@@ -187,6 +193,11 @@ server {
 	{{ end }}
 	access_log /var/log/nginx/access.log vhost;
 
+	{{ if eq $network_tag "internal" }}
+	# Only allow traffic from internal clients
+	include /etc/nginx/network_internal.conf;
+	{{ end }}
+
 	ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
 	ssl_ciphers 'ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:!DSS';
 
@@ -230,11 +241,11 @@ server {
 		auth_basic	"Restricted {{ $host }}";
 		auth_basic_user_file	{{ (printf "/etc/nginx/htpasswd/%s" $host) }};
 		{{ end }}
-                {{ if (exists (printf "/etc/nginx/vhost.d/%s_location" $host)) }}
-                include {{ printf "/etc/nginx/vhost.d/%s_location" $host}};
-                {{ else if (exists "/etc/nginx/vhost.d/default_location") }}
-                include /etc/nginx/vhost.d/default_location;
-                {{ end }}
+		{{ if (exists (printf "/etc/nginx/vhost.d/%s_location" $host)) }}
+		include {{ printf "/etc/nginx/vhost.d/%s_location" $host}};
+		{{ else if (exists "/etc/nginx/vhost.d/default_location") }}
+		include /etc/nginx/vhost.d/default_location;
+		{{ end }}
 	}
 }
 
@@ -250,6 +261,11 @@ server {
 	{{ end }}
 	access_log /var/log/nginx/access.log vhost;
 
+	{{ if eq $network_tag "internal" }}
+	# Only allow traffic from internal clients
+	include /etc/nginx/network_internal.conf;
+	{{ end }}
+
 	{{ if (exists (printf "/etc/nginx/vhost.d/%s" $host)) }}
 	include {{ printf "/etc/nginx/vhost.d/%s" $host }};
 	{{ else if (exists "/etc/nginx/vhost.d/default") }}
@@ -267,11 +283,11 @@ server {
 		auth_basic	"Restricted {{ $host }}";
 		auth_basic_user_file	{{ (printf "/etc/nginx/htpasswd/%s" $host) }};
 		{{ end }}
-                {{ if (exists (printf "/etc/nginx/vhost.d/%s_location" $host)) }}
-                include {{ printf "/etc/nginx/vhost.d/%s_location" $host}};
-                {{ else if (exists "/etc/nginx/vhost.d/default_location") }}
-                include /etc/nginx/vhost.d/default_location;
-                {{ end }}
+		{{ if (exists (printf "/etc/nginx/vhost.d/%s_location" $host)) }}
+		include {{ printf "/etc/nginx/vhost.d/%s_location" $host}};
+		{{ else if (exists "/etc/nginx/vhost.d/default_location") }}
+		include /etc/nginx/vhost.d/default_location;
+		{{ end }}
 	}
 }