shell自動化配置Hadoop配置文件示例
#!/bin/bash
read -p 'Please input the directory of hadoop , ex: /usr/hadoop :' hadoop_dir
if [ -d $hadoop_dir ] ; then
echo 'Yes , this directory exist.'
else
echo 'Error , this directory not exist.'
exit 1
fi
if [ -f $hadoop_dir/conf/core-site.xml ];then
echo "Now config the $hadoop_dir/conf/core-site.xml file."
read -p 'Please input the ip value of fs.default.name , i.e. hdfs://ip:port :' ip
i=1
while [ -z $ip ]
do
read -p 'Please input the ip value of fs.default.name , i.e. hdfs://ip:port :' ip
let i++
echo $i
if [ $i -gt 2 ];then
echo 'You have input three time , done , exit.'
exit 1
fi
done
if [ $ip = '' ];then
echo 'The value of ip can not null , exit.'
exit 1
fi
read -p "Please input the port value of fs.default.name , i.e. hafs://$ip:port :" port
if [ $port = '' ];then
echo 'The value of port can not null , exit.'
exit 1
fi
read -p 'Please input the dir value of hadoop.tmp.dir :' hadoop_tmp_dir
if [ $hadoop_tmp_dir = '' ];then
echo 'The value of hadoop.tmp.dir can not null , exit.'
exit 1
else
if [ ! -d $hadoop_tmp_dir ];then
echo 'The directory you have input is not exist , we will make it.'
mkdir -p $hadoop_tmp_dir
fi
fi
tmp_dir=$(echo $hadoop_tmp_dir|sed 's:/:\\/:g')
sed -i "s/ip/$ip/g" $hadoop_dir/conf/core-site.xml
sed -i "s/port/$port/g" $hadoop_dir/conf/core-site.xml
sed -i "s/tmp_dir/$tmp_dir/g" $hadoop_dir/conf/core-site.xml
else
echo "The file $hadoop_dir/core-site.xml doen't exist."
exit 1
fi
cat $hadoop_dir/conf/core-site.xml
echo 'Config the core-site.xml success !'
echo
關鍵部分分析：
1. tmp_dir=$(echo $hadoop_tmp_dir|sed 's:/:\\/:g')
我們輸入的$hadoop_tmp_dir是類似：/usr/hadoop/tmp這樣的，如果直接寫在sed裡：sed -i "s/tmp_dir/$hadoop_tmp_dir/g" $hadoop_dir/conf/core-site.xml ，這樣會出現錯誤。因為它解析進去會是：sed -i "s/tmp_dir//usr/hadoop/tmp/g" $hadoop_dir/conf/core-site.xml這樣的，顯然不能滿足，這裡解決的方式是：想辦法將/usr/hadoop/tmp的輸入轉換為：\ /usr\ /hadoop\/tmp的形式，即加入轉義字符。sed ' s:/:\\/:g ' 這樣就可以了，然後通過$()，取值賦給變量。
2. sed -i " s/ip/$ip/g " $hadoop_dir/conf/core-site.xml
這裡就是所謂的對文件中字符串的替換，示例文件為：
root@Ubuntu:/home/houqd/hadoop/conf# cat -n core-site.xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs://ip:port</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>tmp_dir</value>
</property>
</configuration>
3. 注意其它語法： if [ ] ; then else fi while [] do ..done i=0 let i++
更多Hadoop相關信息見Hadoop 專題頁面 http://www.linuxidc.com/topicnews.aspx?tid=13
