Use ncat with meas web for multiple clients

modules/rhizo_base/files/etc/sv/meas-json/run

@@ -1,4 +1,10 @@
 #!/bin/bash
 exec 2>&1
 
-exec /usr/bin/stdbuf -oL /usr/bin/meas_json > /tmp/json_pipe
+if [ -a /tmp/json_socket ]; then
+  killall ncat
+  killall meas_json
+  rm -f /tmp/json_socket
+fi
+
+exec /etc/sv/meas-json/scr | ncat -l -U /tmp/json_socket -k --send-only

modules/rhizo_base/files/etc/sv/meas-json/scr

@@ -0,0 +1,3 @@
+#!/bin/sh
+exec 2>&1
+exec /usr/bin/stdbuf -oL /usr/bin/meas_json

modules/rhizo_base/files/etc/sv/meas-web/run

@@ -1,11 +1,3 @@
 #!/bin/bash
 exec 2>&1
-
-if [ ! -p /tmp/json_pipe ] ; then
-  if [ -f /tmp/json_pipe ] ; then
-    rm -f /tmp/json_pipe
-  fi
-  mkfifo /tmp/json_pipe
-fi
-
-exec /usr/bin/websocketd --staticdir=/var/www/meas --port=8080 /etc/sv/meas-web/scr
+exec /usr/bin/websocketd --staticdir=/var/www/meas --port=8080 ncat -U /tmp/json_socket

modules/rhizo_base/files/etc/sv/meas-web/scr

@@ -1,3 +0,0 @@
-#!/bin/sh
-sv restart meas-json
-exec cat /tmp/json_pipe