add start_tracker.sh script for starting trackers

scripts/start_tracker.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+
+_script=$(readlink -f ${BASH_SOURCE[0]})
+BASE_DIR="$(dirname $_script)/../.."
+
+PORT=$1
+RESTART=$(echo "$2" | tr '[:upper:]' '[:lower:]')
+
+STATE_DIR="$BASE_DIR/dispersy-$PORT"
+TWISTD_PID_FILE="$STATE_DIR/twisted.pid"
+
+# set PYTHONPATH
+PYTHONPATH="$BASE_DIR/dispersy:$PYTHONPATH"
+export PYTHONPATH
+
+# check port number
+if [ -z "$PORT" -a "$PORT" != " " ]; then
+    echo "Port number unspecified"
+    echo "Usage: <script> <port> [restart]"
+    echo "  <port>:    The port number to use"
+    echo "  [restart]: use 'true' to restart the tracker if a running one if found"
+    exit 1
+fi
+
+# check and create state_dir
+if [ ! -d "$STATE_DIR" ]; then
+    echo "Creating state_dir $STATE_DIR"
+    mkdir $STATE_DIR
+fi
+
+# check if twistd.pid is present and if a process is already running
+if [ -e "$TWISTD_PID_FILE" ]; then
+    echo "Checking twistd.pid"
+    pid=$(head -1 "$TWISTD_PID_FILE")
+
+    for p in $(ps aux | awk '{print $2}' | tail -n +2)
+    do
+        if [ "$p" == "$pid" ]; then
+            if [ "$RESTART" == "true" ]; then
+                echo "Found a running tracker using port $PORT, restarting"
+                kill $pid
+                sleep 2
+            else
+                echo "Found a running tracker using port $PORT, exiting"
+                exit 1
+            fi
+        fi
+    done
+fi
+
+
+# start tracker
+echo "Starting tracker using port $PORT..."
+twistd --pidfile=$TWISTD_PID_FILE tracker --port=$PORT --statedir=$STATE_DIR
+
+sleep 2
+
+if [ ! -e "$TWISTD_PID_FILE" ]; then
+    echo "Tracker failed to start"
+    exit 3
+fi
+
+echo "done"
+exit 0