Implement IPv6 capability (#826)

* Implement IPv6 capability

Enables uWSGI to listen for IPv6 requests also.
This is done by defaulting to [::] as the listen address, which creates a dual stack socket, which can respond to IPv4 and IPv6 requests simultaneously.
Furthermore a config option is adden to overwrite this default, if a user so desires.

* Add LD_SERVER_HOST to .env.sample

Additionally fix the default name of the LD_SERVER_PORT variable, which was falsely LD_HOST_PORT here.

* revert .env.sample

---------

Co-authored-by: Sascha Ißbrücker <sascha.issbruecker@googlemail.com>

bootstrap.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 # Bootstrap script that gets executed in new Docker containers
 
+LD_SERVER_HOST="${LD_SERVER_HOST:-[::]}"
 LD_SERVER_PORT="${LD_SERVER_PORT:-9090}"
 
 # Create data folder if it does not exist
@@ -32,4 +33,4 @@ if [ "$LD_DISABLE_BACKGROUND_TASKS" != "True" ]; then
 fi
 
 # Start uwsgi server
-exec uwsgi --http :$LD_SERVER_PORT uwsgi.ini
+exec uwsgi --http $LD_SERVER_HOST:$LD_SERVER_PORT uwsgi.ini

docs/Options.md

@@ -62,6 +62,12 @@ Values: `Integer` as seconds | Default = `60`
 
 Configures the request timeout in the uwsgi application server. This can be useful if you want to import a bookmark file with a high number of bookmarks and run into request timeouts.
 
+### `LD_SERVER_HOST`
+
+Values: Valid address for socket to bind to | Default = `[::]`
+
+Allows to set a custom host for the UWSGI server running in the container. The default creates a dual stack socket, which will respond to IPv4 and IPv6 requests. IPv4 requests are logged as IPv4-mapped IPv6 addresses, such as "::ffff:127.0.0.1". If reverting to an IPv4-only socket is desired, this can be set to "0.0.0.0".
+
 ### `LD_SERVER_PORT`
 
 Values: Valid port number | Default = `9090`