Fix argument escaping in Scope

By naively using echo and cat to print to serialize/deserealize arguments we were garbling
arguments with special characters and whitespaces

docker/entrypoint.sh

@@ -13,7 +13,9 @@ for arg in $@; do
     esac
 done
 
-echo "$@" >/var/run/weave/scope-app.args
-echo "$@" >/var/run/weave/scope-probe.args
+ARGS=("$@")
+
+typeset -p ARGS >/var/run/weave/scope-app.args
+typeset -p ARGS >/var/run/weave/scope-probe.args
 
 exec /home/weave/runsvinit

docker/run-app

@@ -1,3 +1,5 @@
 #!/bin/bash
 
-exec -a scope-app /home/weave/scope --mode app $(cat /var/run/weave/scope-app.args)
+source /var/run/weave/scope-app.args
+ 
+exec -a scope-app /home/weave/scope --mode app "${ARGS[@]}"

docker/run-probe

@@ -1,3 +1,5 @@
 #!/bin/bash
 
-exec -a scope-probe /home/weave/scope --mode probe $(cat /var/run/weave/scope-probe.args)
+source /var/run/weave/scope-probe.args
+
+exec -a scope-probe /home/weave/scope --mode probe "${ARGS[@]}"

scope

@@ -143,20 +143,20 @@ launch_command() {
             -v /var/run/docker.sock:/var/run/docker.sock \
             -v /var/run/scope/plugins:/var/run/scope/plugins \
             -e CHECKPOINT_DISABLE \
-            $WEAVESCOPE_DOCKER_ARGS $SCOPE_IMAGE --probe.docker=true "$@"
+            $WEAVESCOPE_DOCKER_ARGS $SCOPE_IMAGE --probe.docker=true
 }
 
 launch_docker4mac_app_command() {
     echo docker run -d --name=$SCOPE_APP_CONTAINER_NAME \
             -e CHECKPOINT_DISABLE \
             -p 0.0.0.0:4040:4040 \
-            $WEAVESCOPE_DOCKER_ARGS $SCOPE_IMAGE --no-probe "$@"
+            $WEAVESCOPE_DOCKER_ARGS $SCOPE_IMAGE --no-probe
 }
 
 launch() {
     check_not_running $SCOPE_CONTAINER_NAME $SCOPE_IMAGE_NAME
     docker rm -f $SCOPE_CONTAINER_NAME >/dev/null 2>&1 || true
-    CONTAINER=$($(launch_command "$@"))
+    CONTAINER=$($(launch_command) "$@")
     echo $CONTAINER
 }
 
@@ -172,7 +172,8 @@ check_docker_version
 
 case "$COMMAND" in
     command)
-        launch_command "$@"
+	# TODO: properly escape/quote the output of "$@"
+        echo $(launch_command) "$@"
         ;;
 
     version)
@@ -220,7 +221,7 @@ EOF
             check_not_running $SCOPE_APP_CONTAINER_NAME $SCOPE_IMAGE_NAME
             check_not_running $SCOPE_CONTAINER_NAME $SCOPE_IMAGE_NAME
             docker rm -f $SCOPE_APP_CONTAINER_NAME >/dev/null 2>&1 || true
-            CONTAINER=$($(launch_docker4mac_app_command "$@"))
+            CONTAINER=$($(launch_docker4mac_app_command) "$@")
             echo $CONTAINER
             app_ip=$(docker inspect -f '{{.NetworkSettings.IPAddress}}' "${CONTAINER}")
             docker rm -f $SCOPE_CONTAINER_NAME >/dev/null 2>&1 || true