catalogue
1. Working mechanism of agency
4. Create Squid service script
3. Client configuration (add agent)
2. Squid modifies firewall and ip forwarding
3,web1 Server modification configuration
1. Define access control lists
1, Squid proxy server
Squid mainly provides cache acceleration and application layer filtering control functions
1. Working mechanism of agency
Instead of the client requesting data from the website, you can hide the user's real IP address
The obtained Web page data (static Web elements) is saved in the cache and sent to the client to respond quickly the next time the same data is requested
2. Type of agent
Traditional proxy: it is applicable to the Internet. You need to specify the address and port of the proxy server on the client
Transparent proxy: the client does not need to specify the address and port of the proxy server, but redirects Web access to the proxy server through default routing and firewall policies
Reverse proxy: if the requested resource is cached in the Squid reverse proxy server, the requested resource is returned directly to the client; Otherwise, the reverse proxy server will request resources from the background WEB server, and then return the requested response to the client. At the same time, it will also cache (statically) the response locally for use by the next requester
3. Benefits of using agents
Improve Web access speed
Hide the real IP address of the client
2, Compile and install Squid
1. Compile and install Squid
systemctl stop firewalld systemctl disable firewalld setenforce 0 yum -y install gcc gcc-c++ make cd /opt tar zxvf squid-3.5.28.tar.gz cd /opt/squid-3.5.28 ./configure --prefix=/usr/local/squid \ #Specify the installation directory path --sysconfdir=/etc \ #Specify profile path --enable-arp-acl \ #MAC address control to prevent clients from using IP spoofing --enable-linux-netfilter \ #Using kernel filtering --enable-linux-tproxy \ #Support transparent mode --enable-async-io=100 \ #Asynchronous IO to improve storage performance --enable-err-language="Simplify_ Chinese" \ #Display language of error message --enable-underscore \ #Allow underscores in URL s --disable-poll \ #Turn off the default use poll mode --enable-gnuregex #Using GNU regular expressions ./configure --prefix=/usr/local/squid \ --sysconfdir=/etc \ --enable-arp-acl \ --enable-linux-netfilter \ --enable-linux-tproxy \ --enable-async-io=100 \ --enable-err-language="Simplify_Chinese" \ --enable-underscore \ --disable-poll \ --enable-epoll \ --enable-gnurege make && make install ln -s /usr/local/squid/sbin/* /usr/local/sbin useradd -M -s /sbin/nologin squid chown -R squid:squid /usr/local/squid/var/ #This directory is used to store cache files
2. Modify squid profile
vim /etc/squid.conf ...... -----56 that 's ok--insert------ http_access allow all #Put on HTTP_ Before access deny all, any client is allowed to use the proxy service to control the top-down matching of rules http_access deny all http_port 3128 #Used to specify the address and port that the proxy service listens to (the default port number is 3128) -----61 that 's ok--insert------ cache_effective_user squid #Add, specify the program user, which is used to set the account of initialization and runtime cache. Otherwise, the startup will not succeed cache_effective_group squid #Add, specify account basic group coredump_dir /usr/local/squid/var/cache/squid #Specify cache file directory
3. Squid operation control
#Check whether the configuration file syntax is correct squid -k parse squid –k rec ##Reload profile #Start Squid. When Squid service is started for the first time, the cache directory will be initialized automatically squid -zX #-The z option is used to initialize the cache directory squid #Start squid service netstat -anpt | grep 3128
4. Create Squid service script
vim /etc/init.d/squid
#!/bin/bash
#chkconfig: 2345 90 25
#2345 is the default self startup level. If yes - means that no self startup is available at any level; 90 is the start priority, 25 is the stop priority, and the priority range is 0-100. The higher the number, the lower the priority.
PID="/usr/local/squid/var/run/squid.pid"
CONF="/etc/squid.conf"
CMD="/usr/local/squid/sbin/squid"
case "$1" in
start)
netstat -natp | grep squid &> /dev/null
if [ $? -eq 0 ]
then
echo "squid is running"
else
echo "Starting squid..."
$CMD
fi
;;
stop)
$CMD -k kill &> /dev/null
rm -rf $PID &> /dev/null
;;
status)
[ -f $PID ] &> /dev/null
if [ $? -eq 0 ]
then
netstat -natp | grep squid
else
echo "squid is not running"
fi
;;
restart)
$0 stop &> /dev/null
echo "Closing squid..."
$0 start &> /dev/null
echo "Starting squid..."
;;
reload)
$CMD -k reconfigure
;;
check)
$CMD -k parse
;;
*)
echo "Usage: $0{start|stop|status|reload|check|restart}"
;;
esac
chmod +x /etc/init.d/squid
chkconfig --add squid
chkconfig --level 35 squid on
vim /etc/init.d/squid
#!/bin/bash
#chkconfig: 2345 90 25
#2345 is the default self startup level. If yes - means that no self startup is available at any level; 90 is the start priority, 25 is the stop priority, and the priority range is 0-100. The higher the number, the lower the priority.
PID="/usr/local/squid/var/run/squid.pid"
CONF="/etc/squid.conf"
CMD="/usr/local/squid/sbin/squid"
case "$1" in
start)
netstat -natp | grep squid &> /dev/null
if [ $? -eq 0 ]
then
echo "squid is running"
else
echo "Starting squid..."
$CMD
fi
;;
stop)
$CMD -k kill &> /dev/null
rm -rf $PID &> /dev/null
;;
status)
[ -f $PID ] &> /dev/null
if [ $? -eq 0 ]
then
netstat -natp | grep squid
else
echo "squid is not running"
fi
;;
restart)
$0 stop &> /dev/null
echo "Closing squid..."
$0 start &> /dev/null
echo "Starting squid..."
;;
reload)
$CMD -k reconfigure
;;
check)
$CMD -k parse
;;
*)
echo "Usage: $0{start|stop|status|reload|check|restart}"
;;
esac
chmod +x /etc/init.d/squid
chkconfig --add squid
chkconfig --level 35 squid on
vim /etc/init.d/squid
#!/bin/bash
#chkconfig: 2345 90 25
#2345 is the default self startup level. If yes - means that no self startup is available at any level; 90 is the start priority, 25 is the stop priority, and the priority range is 0-100. The higher the number, the lower the priority.
PID="/usr/local/squid/var/run/squid.pid"
CONF="/etc/squid.conf"
CMD="/usr/local/squid/sbin/squid"
case "$1" in
start)
netstat -natp | grep squid &> /dev/null
if [ $? -eq 0 ]
then
echo "squid is running"
else
echo "Starting squid..."
$CMD
fi
;;
stop)
$CMD -k kill &> /dev/null
rm -rf $PID &> /dev/null
;;
status)
[ -f $PID ] &> /dev/null
if [ $? -eq 0 ]
then
netstat -natp | grep squid
else
echo "squid is not running"
fi
;;
restart)
$0 stop &> /dev/null
echo "Closing squid..."
$0 start &> /dev/null
echo "Starting squid..."
;;
reload)
$CMD -k reconfigure
;;
check)
$CMD -k parse
;;
*)
echo "Usage: $0{start|stop|status|reload|check|restart}"
;;
esac
chmod +x /etc/init.d/squid
chkconfig --add squid
chkconfig squid on
service squid restart ##The test is normal
3, Traditional agent
1. squid server
vim /etc/squid.conf ...... http_access allow all http_access deny all http_port 3128 cache_effective_user squid cache_effective_group squid #63 line insert cache_mem 64 MB #Specify the memory space used by the cache function to maintain frequently accessed WEB objects. The capacity is preferably a multiple of 4, in MB. It is recommended to set it to 1 / 4 of the physical memory reply_body_max_size 10 MB #The maximum file size that users are allowed to download, in bytes. When downloading a Web object of more than the specified size, a prompt of "request or access too large" will appear on the error page of the browser. The default setting is 0, which means no restriction maximum_object_size 4096 KB #The maximum object size allowed to be saved to the cache space, in KB. Files exceeding the size limit will not be cached, but will be forwarded directly to the user service squid restart systemctl restart squid #Modify firewall rules iptables -F iptables -I INPUT -p tcp --dport 3128 -j ACCEPT
2. web1 configuration
systemctl stop firewalld.service setenforce 0 yum -y install httpd systemctl start httpd netstat -natp | grep 80
3. Client configuration (add agent)
4. Test results
#Dynamically view the access log on web1 and observe the visiting IP tail -f /var/log/httpd/access_log Client access 192.168.255.150
4, Transparent proxy
1. Squid server configuration
cd /etc/sysconfig/network-scripts/ cp ifcfg-ens33 ifcfg-ens37 vim ifcfg-ens37 systemctl restart network yum install iptables* -y #In line 60, modify and add the IP address that provides intranet services, and support the transparent proxy option transparent vim /etc/squid.conf ...... http_access allow all http_access deny all http_port 192.168.174.1:3128 transparent systemctl restart squid
2. Squid modifies firewall and ip forwarding
echo 'net.ipv4.ip_forward = 1' >> /etc/sysctl.conf sysctl -p iptables -F iptables -t nat -F iptables -t nat -I PREROUTING -i ens37 -s 192.168.174.0/24 -p tcp --dport 80 -j REDIRECT --to 3128 iptables -t nat -I PREROUTING -i ens37 -s 192.168.174.0/24 -p tcp --dport 443 -j REDIRECT --to 3128 iptables -I INPUT -p tcp --dport 3128 -j ACCEPT
3,web1 Server modification configuration
to configure web1 Gateway points to 192.168.255.180 iptables -F
4. Access web1 server
web1 Dynamically view the access log and observe the visit IP tail -f /var/log/httpd/access_log
5, ACL access control
In the configuration file squid.conf, ACL access control is realized through the following two steps:
① Use acl configuration items to define the conditions that need to be controlled
② Via http_ The access configuration item controls "allow" or "deny" access to the defined list
1. Define access control lists
acl List name list type list content List name: custom name, equivalent to acl Give a name (a bit similar to shell Script variable name) List type: required squid Predefined values, corresponding to different categories of control conditions List content: refers to the specific object to be controlled. The corresponding contents of different types of lists are also different. There can be multiple values (separated by spaces and the relationship of "or")
Method 1
vim /etc/squid.conf ....... acl localhost src 192.168.174.142/24 #The source address is 192.168.174.142 acl MYLAN src 192.168.255.0/24 #Client network segment acl destinationhost dst 192. 168.255.150/24 #The destination address is 192.168.255.150 acl MC20 maxconn 20 #Maximum concurrent connections 20 acl PORT port 21 #Target port 21 acl DMBLOCK dstdomain .qq.com #Target domain, matching all sites in the domain acl BURL url_regex -i ^rtsp:// ^emule:// # URL s starting with RTSP: / /. Module: / /, - i means case is ignored acl PURL urlpath_regex -i \.mp3$ \.mp4$ \.rmvb$ #URL path ending in. mp3,. mp4,. rmvb acl WORKTIME time MTWHF 08:30-17:30 #The time is 8:30 ~ 17:30 from Monday to Friday, "MTWHF" is the English initials of each week http_access deny host service squid reload
Method 2
#Start object list management mkdir /etc/squid vim /etc/squid/dest.list 192.168.255.180 #Squid server IP 192.168.255.0/24 #Any required network segment vim /etc/squid.conf ...... acl destinationhost dst "/etc/squid/dest.list" #Call the contents of the list in the specified file http_access deny (or allow) destinationhost #Note that if it is a rejection list, it needs to be placed in http_access allow all systemctl restart squid
6, Squid log analysis
sarg (Squid Analysis Report Generator) is a squid log analysis tool, which uses HTML format to list in detail the site information, time occupation information, ranking, connection times, traffic, etc. of each user accessing the Internet
#Install image processing package yum install -y gd gd-devel pcre-devel mkdir /usr/local/sarg #Upload the zxvf sarg-2.3.7.tar.gz compressed package to the / opt directory tar zxvf sarg-2.3.7.tar.gz -C /opt/ cd /opt/sarg-2.3.7 ./configure --prefix=/usr/local/sarg \ --sysconfdir=/etc/sarg \ #The configuration file directory is / usr/loca/etc by default --enable-extraprotection #Additional safety protection ./configure --prefix=/usr/local/sarg --sysconfdir=/etc/sarg --enable-extraprotection make && make install vim /etc/sarg/sarg.conf --7 that 's ok--note off access_log /usr/local/squid/var/logs/access.log #Specify access log file --25 that 's ok--note off title "Squid User Access Reports" #Page title --120 that 's ok--Uncomment, modify output_dir /var/www/html/sarg #Report output directory --178 that 's ok--note off user_ip no #Display with user name --184 that 's ok--Uncomment, modify topuser_sort_field connect reverse #In top sorting, the specified connection times are arranged in descending order, and the ascending order is normal --190 that 's ok--Uncomment, modify user_sort_field connect reverse #For user access records, the number of connections is sorted in descending order --206 that 's ok--Uncomment, modify exclude_hosts /usr/local/sarg/noreport #Specifies files that are not included in the sorted site list --257 that 's ok--note off overwrite_report no #Overwrite logs with the same name and date --289 that 's ok--Uncomment, modify mail_utility mailq.postfix #Send mail report command --434 that 's ok--Uncomment, modify charset UTF-8 #Specifies the character set UTF-8 --518 that 's ok--note off weekdays 0-6 #Week cycle of top ranking --525 that 's ok--note off hours 0-23 #Time period of top ranking --633 that 's ok--note off www_document_root /var/www/html #Specify page root #Add is not included in the site file, and the added domain name will not be displayed in the sorting touch /usr/local/sarg/noreport ln -s /usr/local/sarg/bin/sarg /usr/local/bin/ sarg --help #get help #function sarg #Start a record #verification yum install httpd -y systemctl start httpd iptables -I INPUT -p tcp --dport 80 -j ACCEPT stay squid Use browser access on the server http://192.168.255.180/sarg, check the Sarg report page. #Add scheduled tasks to perform daily report generation vim /usr/local/sarg/report.sh #/bin/bash #Get current date TODAY=$(date +%d/%m/%Y) #Get one week ago today YESTERDAY=$(date -d "1 day ago" +%d/%m/%Y) /usr/local/sarg/bin/sarg -l /usr/local/squid/var/logs/access.log -o /var/www/html/sarg -z -d $YESTERDAY-$TODAY &> /dev/null exit 0 chmod +x /usr/local/sarg/report.sh crontab -e 0 0 * * * /usr/local/sarg/report.sh Manual mode #Direct access squid http://192.168.255.180/sarg Periodic scheduling task execution generates reports every day, and crontab-o outputs them to the report directory sarg -l /usr/local/squid/var/logs/access.log -o /var/www/html/sarg -z -d $(date -d "1 day ago" +%d/%m/%Y)-$(date +%d/%m/%Y) ##Execute again to generate a new report, and the page can see the log report record of one more day http://192.168.255.180/sarg/index.html sarg -l /usr/local/squid/var/logs/access.log -o /var/www/html/sarg -z -d $(date -d "1 day ago" +%d/%m/%Y)-$(date +%d/%m/%Y)
7, Reverse proxy
If the requested resource is cached in the Squid reverse proxy server, the requested resource is directly returned to the client; Otherwise, the reverse proxy server will request resources from the background Web server, and then return the requested response to the client. At the same time, it will also cache the response locally for use by the next requester
1. Working mechanism
Cache web page objects to reduce duplicate requests
Internet requests are polled or weighted to intranet web servers
Proxy user requests to avoid users directly accessing the Web server and improve security
Turn on firewall and turn off local HTTPD systemctl start firewalld systemctl stop httpd iptables -F iptables -t nat -F iptables -I INPUT -p tcp --dport 80 -j ACCEPT vim /etc/squid.conf ------ 60 that 's ok--Modify, insert------- http_port 192.168.255.180:80 accel vhost vport cache_peer 192.168.255.150 parent 80 0 no-query originserver round-robin max_conn=30 weight=1 name=web1 cache_peer 192.168.255.200 parent 80 0 no-query originserver round-robin max_conn=30 weight=1 name=web2 cache_peer_domain web1 web2 www.ly.com #Indicates a request for www.ly.com. squid sends a request to port 80 of 192.168.255.150 and 192.168.255.200 ------------------------------------------------------------------------------------- http_port 80 accel vhost vport #Squid has changed from a cache to a Web server reverse proxy acceleration mode. At this time, squid listens to requests on port 80 and binds to the request port (vhost vport) of webserver. When a request arrives at squid, squid does not need to forward the request. Instead, it directly needs to take data from the cache or directly request data from the bound port. accel :Reverse proxy acceleration mode vhost:Support domain name or host name to represent proxy node vport :support IP And port to represent the proxy node parent :Represents the parent node, the parent node, the parent node, the parent node, the parent node, and the parent node 80:Agent internal web Port 80 of the server 0 :Not used icp，It means just one squid The server no-query :Get data directly without query originserver :Specify source server round-robin :appoint squid The request is distributed to one of the parent nodes by polling max_conn :Specify the maximum number of connections weight :Specify weights name :Set alias ---------------------------------------------------------------------------------------- systemctl stop httpd service squid reload #Backend web2 node server settings yum install -y httpd systemctl start httpd #Node 1(web1): echo "this is test01" >> /var/www/html/index.html #Node 2(web2): echo "this is test02" >> /var/www/html/index.html #Domain name mapping configuration for client /etc/hosts file 192.168.255.180 www.ly.com #Proxy configuration for client Open browser, tools-->Internet option-->connect-->LAN settings-->Turn on the proxy server(address: Squid The server IP Address, port: 80) Browser access http://www.ly.com
summary
squid Positioning is cache acceleration. The cache is obtained from the back-end web server. The acceleration is for client access
squid has three modes:
1. Traditional proxy: the client needs to point to the squid proxy server, and the client can perceive the existence of the squid proxy server
2. Transparent proxy (commonly used): the client does not need to be configured, but can be accessed directly. The server completes the transparent proxy with the help of firewall rules and static routing
3. Reverse proxy: as a reverse proxy function similar to the Nginx server, it does not need a home page. It completes the reverse proxy based on IP: port and weight
For Squid's own management / functions
ACL: mainly used for http_ Permission and denial management of access (access based on http protocol)
sarg: log analysis function. Access can be specified in days_ The contents of the log are output to a web page (with the help of httpd) for display.