修改： 现在只检测星火源的更新，避免出现问题

新文件：   检测网络环境，没网就退出

debian/spark-store.postinst

@@ -20,7 +20,7 @@ case "$1" in
 		cp -f /tmp/spark-store-install/spark-store.asc.gpg /etc/apt/trusted.gpg.d/spark-store.gpg
 
         	# Run apt update to avoid users being fucked up by the non-exist dependency problem
-        	apt update
+        	apt update -o Dir::Etc::sourcelist="sources.list.d/sparkstore.list"     -o Dir::Etc::sourceparts="-" -o APT::Get::List-Cleanup="0"`
 
 		# Create symbo links to start upgrade detect
 		ln -s /opt/durapps/spark-store/bin/update-upgrade/autostart/spark-update-notifier.desktop /etc/xdg/autostart/spark-update-notifier.desktop

debian/spark-store.preinst

@@ -0,0 +1,27 @@
+#!/bin/bash
+#检测网络链接畅通
+function network-check()
+{
+    #超时时间
+    local timeout=1
+
+    #目标网站
+    local target=www.baidu.com
+
+    #获取响应状态码
+    local ret_code=`curl -I -s --connect-timeout ${timeout} ${target} -w %{http_code} | tail -n1`
+
+    if [ "x$ret_code" = "x200" ]; then
+        echo "Network Checked successful ! Continue..."
+	 echo "网络通畅，继续安装"
+    else
+        #网络不畅通
+	echo "Network failed ! Cancel the installation"
+	echo "网络不畅，终止安装"
+	exit -1
+    fi
+
+}
+
+
+network-check