获取active nn并替换hue.ini

namenodelists="nnip1,nnip2"
nn1=$(echo $namenodelists | cut -d "," -f 1)
nn2=$(echo $namenodelists | cut -d "," -f 2)
nn1state=$(curl "http://$nn1:50070/jmx?qry=Hadoop:service=NameNode,name=NameNodeStatus"|grep -c active)
nn2state=$(curl "http://$nn2:50070/jmx?qry=Hadoop:service=NameNode,name=NameNodeStatus"|grep -c active)

source /etc/profile
source /root/.profile
curr_nn=$(grep -Po -m1 "http://(.*):50070" /usr/share/hue/desktop/conf/hue.ini |cut -d ':' -f 2|cut -d "/" -f 3)
echo $curr_nn
if [ $nn1state -eq 1 ]; then
activenn=$nn1
   if [ "X$curr_nn" != "X$activenn" ]; then 
       echo "nn change, now active is $activenn"
       sed -i "s|fs_defaultfs=.*|webhdfs_url=http://$activenn:50070/webhdfs/v1|" /usr/share/hue/desktop/conf/hue.ini 
       sed -i "s|webhdfs_url=.*|webhdfs_url=http://$activenn:50070/webhdfs/v1|" /usr/share/hue/desktop/conf/hue.ini
       ps -ef|grep hue |grep -v grep |awk '{print $2}' |xargs kill -9 2>/dev/null
       /usr/bin/nohup /usr/share/hue/build/env/bin/hue runserver 0.0.0.0:8888 > /usr/share/hue/hue.log 2>&1 &
   fi
fi
if [ $nn2state -eq 1 ]; then
activenn=$nn2
   if [ "X$curr_nn" != "X$activenn" ]; then 
       echo "nn change, now active is $activenn"
       sed -i "s|fs_defaultfs=.*|webhdfs_url=http://$activenn:50070/webhdfs/v1|" /usr/share/hue/desktop/conf/hue.ini 
       sed -i "s|webhdfs_url=.*|webhdfs_url=http://$activenn:50070/webhdfs/v1|" /usr/share/hue/desktop/conf/hue.ini
       ps -ef|grep hue |grep -v grep |awk '{print $2}' |xargs kill -9 2>/dev/null
       /usr/bin/nohup /usr/share/hue/build/env/bin/hue runserver 0.0.0.0:8888 > /usr/share/hue/hue.log 2>&1 &
   fi
fi
#start it if not start 
live=`ps -ef|grep runserver|grep -v -c grep`
if [ $live -eq 0 ];  then
/usr/bin/nohup /usr/share/hue/build/env/bin/python2.7 /usr/share/hue/build/env/bin/hue runserver 0.0.0.0:8888 2>&1 &
fi

当前使用hdp3.1,安装namenode ha,配置hue使用的时候需要安装httpfs,但这个版本的httpfs是空的包，安装后很多目录都没有，不能用，

所以采用了上面的方法，配置一个crontab * * * * * /xxx.sh 一分钟检查一次，如果active nn和配置文件中的active nn不一致，则就更新配置，

然后重启hue.

遇到的一个问题是配置在crontab 中不会把hue拉起来，测了很久发现`` $()有问题，改成``的方式是可以的。

上网查找相关的内容，也没有得到很好的解析，有一种说法是``中的内容本身就是经过转义的（和此也 无关的）