[curl] Added curl_interface option #30

Improves #30

README.rst

@@ -74,6 +74,10 @@ UCI configuration options must go in ``/etc/config/openwisp``.
 - ``connect_timeout``: value passed to curl ``--connect-timeout`` argument, defaults to ``15``; see `curl connect-timeout argument <https://curl.haxx.se/docs/manpage.html#--connect-timeout>`_
 - ``max_time``: value passed to curl ``--max-time`` argument, defaults to ``30``; see `curl connect-timeout argument <https://curl.haxx.se/docs/manpage.html#-m>`_
 - ``mac_interface``: the interface from which the MAC address is taken when performing automatic registration, defaults to ``eth0``
+- ``curl_interface``: the value passed to curl ``--interface`` argument, it may have 3 different type of values:
+  - ``0``: disabled (default value)
+  - ``1``: enabled and automatically uses the value of the ``interface`` option
+  - ``<interface_name>``: explicit interface name, eg: ``br-wan``
 - ``pre_reload_hook``: path to custom executable script, see `pre-reload-hook`_
 
 Automatic registration

openwisp-config/files/openwisp-nossl.config

@@ -22,5 +22,6 @@ config controller 'http'
 	#option max_time '30'
 	#option capath '/etc/ssl/certs'
 	#option cacert '/etc/ssl/certs/ca-certificates.crt'
+	#option curl_interface '0'
 	# hooks
 	#option pre_reload_hook '/usr/sbin/my_pre_reload_hook'

openwisp-config/files/openwisp-ssl.config

@@ -22,5 +22,6 @@ config controller 'http'
 	#option max_time '30'
 	#option capath '/etc/ssl/certs'
 	#option cacert '/etc/ssl/certs/ca-certificates.crt'
+	#option curl_interface '0'
 	# hooks
 	#option pre_reload_hook '/usr/sbin/my_pre_reload_hook'

openwisp-config/files/openwisp.agent

@@ -20,6 +20,7 @@ while [ -n "$1" ]; do
 		--capath) export CAPATH="$2"; shift;;
 		--cacert) export CACERT="$2"; shift;;
 		--mac-interface) export MAC_INTERFACE="$2"; shift;;
+		--curl-interface) export CURL_INTERFACE="$2"; shift;;
 		--pre-reload-hook) export PRE_RELOAD_HOOK="$2"; shift;;
 		-*)
 			echo "Invalid option: $1"
@@ -69,7 +70,7 @@ STATUS_REPORT="$WORKING_DIR/status_report"
 APPLYING_CONF="$WORKING_DIR/applying_conf"
 REGISTRATION_URL="$URL/controller/register/"
 UNMANAGED_DIR="$WORKING_DIR/unmanaged"
-FETCH_COMMAND="curl -s --connect-timeout $CONNECT_TIMEOUT --max-time $MAX_TIME --interface $MAC_INTERFACE"
+FETCH_COMMAND="curl -s --connect-timeout $CONNECT_TIMEOUT --max-time $MAX_TIME"
 mkdir -p $WORKING_DIR
 mkdir -p $UNMANAGED_DIR
 
@@ -84,6 +85,13 @@ else
 	fi
 fi
 
+if [ "$CURL_INTERFACE" == "1" ]; then
+	CURL_INTERFACE="$MAC_INTERFACE"
+fi
+if [ -n "$CURL_INTERFACE" ] && [ "$CURL_INTERFACE" != "0" ]; then
+	FETCH_COMMAND="$FETCH_COMMAND --interface $CURL_INTERFACE"
+fi
+
 if [ -n "$UNMANAGED" ]; then
 	# replace commas with spaces
 	UNMANAGED=$(echo $UNMANAGED | tr ',' ' ')

openwisp-config/files/openwisp.init

@@ -24,6 +24,7 @@ start_service() {
 	capath=$(config_get http capath)
 	cacert=$(config_get http cacert)
 	mac_interface=$(config_get http mac_interface)
+	curl_interface=$(config_get http curl_interface)
 	pre_reload_hook=$(config_get http pre_reload_hook)
 	if [ $url ]; then url="--url $url"; fi
 	if [ $interval ]; then interval="--interval $interval"; fi
@@ -46,6 +47,7 @@ start_service() {
 	if [ $capath ]; then capath="--capath $capath"; fi
 	if [ $cacert ]; then cacert="--cacert $cacert"; fi
 	if [ $mac_interface ]; then mac_interface="--mac-interface $mac_interface"; fi
+	if [ $curl_interface ]; then curl_interface="--curl-interface $curl_interface"; fi
 	if [ $pre_reload_hook ]; then pre_reload_hook="--pre-reload-hook $pre_reload_hook"; fi
 
 	if [ -z "$url" ]; then
@@ -66,7 +68,7 @@ start_service() {
 	procd_set_param command $PROG $url $interval $verify_ssl $uuid $key $shared_secret \
 	                        $consistent_key $unmanaged $merge_config $test_config \
 	                        $test_script $connect_timeout $max_time $capath $cacert \
-	                        $mac_interface $pre_reload_hook
+	                        $mac_interface $curl_interface $pre_reload_hook
 	procd_set_param respawn
 	procd_close_instance
 	logger -s "$PROG_NAME started" \