upstart: add blocknet which blocks net until after cloud-init-local

This makes it so networking wont start to come up until after
cloud-init-local has had a chance to search local datasources
and set /etc/network/interfaces.

The changes most likely need to still be done for systemd.

upstart/cloud-init-blocknet.conf

@@ -0,0 +1,83 @@
+# cloud-init-blocknet
+# the purpose of this job is
+#  * to block networking from coming up until cloud-init-nonet has run
+#  * timeout if they all do not come up in a reasonable amount of time
+description "block networking until cloud-init-local"
+start on (starting network-interface
+          or starting network-manager
+          or starting networking)
+stop on stopped cloud-init-local
+
+instance $JOB${INTERFACE:+/}${INTERFACE:-}
+export INTERFACE
+task
+
+script
+   set +e  # you cannot trap TERM reliably with 'set -e'
+   SLEEP_CHILD=""
+   LOG="/run/${UPSTART_JOB}.log"
+
+   static_network_up() {
+      local emitted="/run/network/static-network-up-emitted"
+      # /run/network/static-network-up-emitted is written by
+      # upstart (via /etc/network/if-up.d/upstart). its presense would
+      # indicate that static-network-up has already fired.
+      [ -e "$emitted" -o -e "/var/$emitted" ]
+   }
+   msg() {
+      local uptime="" idle="" msg=""
+      if [ -r /proc/uptime ]; then
+         read uptime idle < /proc/uptime
+      fi
+      msg="${UPSTART_INSTANCE}${uptime:+[${uptime}]}: $*"
+      echo "$msg" >> "$LOG"
+      echo "$msg"
+   }
+
+   handle_sigterm() {
+      # if we received sigterm and static networking is up then it probably
+      # came from upstart as a result of 'stop on static-network-up'
+      msg "got sigterm"
+      if [ -n "$SLEEP_CHILD" ]; then
+          if ! kill $SLEEP_CHILD 2>/dev/null; then
+              [ ! -d "/proc/$SLEEP_CHILD" ] ||
+                  msg "hm.. failed to kill sleep pid $SLEEP_CHILD"
+          fi
+      fi
+      msg "stopped"
+      exit 0
+   }
+
+   dowait() {
+      msg "blocking $1 seconds"
+      # all this 'exec -a' does is get me a nicely named process in 'ps'
+      # ie, 'sleep-block-network-interface.eth1'
+      if [ -x /bin/bash ]; then 
+         bash -c 'exec -a sleep-block-$1 sleep $2' -- "$UPSTART_INSTANCE" "$1" &
+      else
+         sleep "$1" &
+      fi
+      SLEEP_CHILD=$!
+      msg "sleepchild=$SLEEP_CHILD"
+      wait $SLEEP_CHILD
+      SLEEP_CHILD=""
+   }
+
+   trap handle_sigterm TERM
+
+   if [ -n "$INTERFACE" -a "${INTERFACE#lo}" != "${INTERFACE}" ]; then
+     msg "ignoring interface ${INTERFACE}";
+     exit 0;
+   fi
+
+   # static_network_up already occurred
+   static_network_up && { msg "static_network_up already"; exit 0; }
+
+   # local-finished cloud-init-local success or failure
+   lfin="/run/cloud-init/local-finished"
+   [ -f "$lfin" ] && { msg "$lfin found"; exit 0; }
+
+   dowait 120
+   msg "gave up waiting for $lfin"
+   exit 1
+end script

upstart/cloud-init-local.conf

@@ -6,4 +6,11 @@ task
 
 console output
 
-exec /usr/bin/cloud-init init --local  
+script
+  lfin=/run/cloud-init/local-finished
+  ret=0
+  cloud-init init --local || ret=$?
+  [ -r /proc/uptime ] && read up idle < /proc/uptime || up="N/A"
+  echo "$ret up $up" > "$lfin"
+  exit $ret
+end script

upstart/cloud-init-nonet.conf

@@ -58,9 +58,8 @@ script
    # static_network_up already occurred
    static_network_up && exit 0
 
-   # obj.pkl comes from cloud-init-local (or previous boot and
-   # manual_cache_clean)
-   [ -f /var/lib/cloud/instance/obj.pkl ] && exit 0
+   # local-finished comes from cloud-init-local
+   [ -f /run/cloud-init/local-finished ] && exit 0
 
    dowait 10
    dowait 120