Move to Alpine linux

Based on https://github.com/sanjeevan/baseimage

Image size reduced from 232MB to 90MB

Also make the change monitors more like services that restart if they crash

boot.sh

@@ -0,0 +1,56 @@
+#!/bin/sh
+
+# Based on https://github.com/sanjeevan/baseimage
+
+shutdown() {
+  echo
+  echo "Shutting down container..."
+
+  # first shutdown any service started by runit
+  for _srv in $(ls -1 /etc/service); do
+    sv force-stop $_srv
+  done
+
+  # shutdown runsvdir command
+  kill -HUP $RUNSVDIR
+  wait $RUNSVDIR
+
+  # give processes time to stop
+  sleep 0.5
+
+  # kill any other processes still running in the container
+  for _pid  in $(ps -eo pid | grep -v PID  | tr -d ' ' | grep -v '^1$' | head -n -6); do
+    timeout -t 5 /bin/sh -c "kill $_pid && wait $_pid || kill -9 $_pid"
+  done
+
+  exit
+}
+
+# catch shutdown signals
+trap shutdown SIGTERM SIGHUP SIGQUIT SIGINT
+
+# store environment variables
+export > /etc/envvars
+
+PATH=/bin:/sbin:/usr/bin
+
+# run all scripts in the run_once folder
+if ! /bin/run-parts /etc/run_once
+then
+  echo "Run-once scripts failed. Stopping container"
+  shutdown
+fi
+
+exec env - PATH=$PATH runsvdir -P /etc/service &
+
+RUNSVDIR=$!
+echo "Started runsvdir, PID is $RUNSVDIR. Waiting for processes to start...."
+
+sleep 5
+for _srv in $(ls -1 /etc/service); do
+    sv status $_srv
+done
+
+wait $RUNSVDIR
+
+shutdown