Provide a way to skip the templating for torrc (#164)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

README.md

@@ -51,6 +51,11 @@ available:
 Note that the defaults are the same as Tor's default if the
 configuration option is not set.
 
+If you set the SKIP_TEMPLATE variable to any value, the whole
+templating logic will be disabled and the configuration file
+/etc/tor/torrc will be used as is (either the default one provided by
+Tor or yours if you mount one in the container).
+
 You can use the `-m` option of Docker to mount a custom template in the
 image at `/etc/tor/torrc.template`. The templating engine
 (`envsubst`) will only replace specific environment variables in the

tor/tor-wrapper.sh

@@ -22,6 +22,12 @@ if [ -f '/etc/torrc' ]; then
 		\echo 'DEBUG: Found existing /etc/torrc, overwritting /etc/tor/torrc.'
 	fi
 	\cp -f '/etc/torrc' '/etc/tor/torrc'
+	\echo 'WARN: Found configuration file at deprecated location /etc/torrc. Please use /etc/tor/torrc instead or it will stop working in future releases of this image.'
+elif [ -n "${SKIP_TEMPLATE+x}" ]; then
+	if [ "${DEBUG}" = true ]; then
+		\echo "DEBUG: Skipping templating since SKIP_TEMPLATE is set."
+	fi
+	\echo "Skipping templating."
 else
 	if [ -n "${SHELL_FORMAT+x}" ]; then
 		if [ "${DEBUG}" = true ]; then