学习Nginx（一）

实验目的

通过nginx实现反向代理的功能，类似apache反向代理和haproxy反向代理

工作中用nginx做反向代理和负载均衡的也越来越多了

有些公司从web服务器到反向代理，都使用nginx。nginx在1.9版本加入了tcp的反向代理功能
甚至安全策略：nginx+lua 完全可以搞定。

打开nginx官网

nginx做反向代理，安装命令如下，使用www用户运行nginx

useradd -s /sbin/noglogin -M www

wget http://nginx.org/download/nginx-1.9.12.tar.gz

tar zxf nginx-1.9.12.tar.gz

cd nginx-1.9.12

./configure --prefix=/usr/local/nginx-1.9.12 \

--user=www --group=www --with-http_ssl_module \

--with-http_stub_status_module --with-file-aio

make && make install

ln -s /usr/local/nginx-1.9.12/ /usr/local/nginx

检查语法

[[email protected] nginx-1.9.12]# /usr/local/nginx/sbin/nginx -t

nginx: the configuration file /usr/local/nginx-1.9.12/conf/nginx.conf syntax is ok

nginx: configuration file /usr/local/nginx-1.9.12/conf/nginx.conf test is successful

[[email protected] nginx-1.9.12]#

检查服务器有无其它服务占用80端口，可以关闭了。

1	`[[email protected] ~]# /usr/local/httpd/bin/apachectl -k stop`

配置nginx反向代理，修改主配置文件

gzip是默认关闭的
长连接默认打开的
sendfile 默认打开的

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[[email protected] conf]# cat nginx.conf

#user nobody;

worker_processes 1;

#error_log logs/error.log;

#error_log logs/error.log notice;

#error_log logs/error.log info;

#pid logs/nginx.pid;

events {

worker_connections 10240;

}

http {

include mime.types;

default_type application/octet-stream;

#log_format main ‘$remote_addr - $remote_user [$time_local] "$request" ‘

# ‘$status $body_bytes_sent "$http_referer" ‘

# ‘"$http_user_agent" "$http_x_forwarded_for"‘;

#access_log logs/access.log main;

sendfile on;

#tcp_nopush on;

#keepalive_timeout 0;

keepalive_timeout 65;

#gzip on;

upstream backend {

server 10.0.1.105:8080 weight=1 max_fails=3 fail_timeout=30s;

server 10.0.1.106:8080 weight=2 max_fails=3 fail_timeout=30s;

}

server {

listen 80;

server_name www.nginx-nmap.com;

#charset koi8-r;

#access_log logs/host.access.log main;

location / {

root html;

index index.html index.htm;

proxy_pass http://backend;

}

#error_page 404 /404.html;

# redirect server error pages to the static page /50x.html

#

error_page 500 502 503 504 /50x.html;

location = /50x.html {

root html;

}

# proxy the PHP scripts to Apache listening on 127.0.0.1:80

#

#location ~ \.php$ {

# proxy_pass http://127.0.0.1;

#}

# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000

#

#location ~ \.php$ {

# root html;

# fastcgi_pass 127.0.0.1:9000;

# fastcgi_index index.php;

# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;

# include fastcgi_params;

#}

# deny access to .htaccess files, if Apache‘s document root

# concurs with nginx‘s one

#

#location ~ /\.ht {

# deny all;

#}

}

# another virtual host using mix of IP-, name-, and port-based configuration

#

#server {

# listen 8000;

# listen somename:8080;

# server_name somename alias another.alias;

# location / {

# root html;

# index index.html index.htm;

# }

#}

# HTTPS server

#

#server {

# listen 443 ssl;

# server_name localhost;

# ssl_certificate cert.pem;

# ssl_certificate_key cert.key;

# ssl_session_cache shared:SSL:1m;

# ssl_session_timeout 5m;

# ssl_ciphers HIGH:!aNULL:!MD5;

# ssl_prefer_server_ciphers on;

# location / {

# root html;

# index index.html index.htm;

# }

#}

}

[[email protected] conf]#

上面设置虚拟主机名www.nginx-nmap.com，以及后端集群组backend，设置了location把任何请求都发给后端backend

上面配置文件里也设置了后端web集群

负载均衡配置时的2个参数：fail_timeout和max_fails
这2个参数一起配合，来控制nginx怎样认为upstream中的某个server是失效的当在fail_timeout的时间内，某个server连接失败了max_fails次，则nginx会认为该server不工作了。
同时，在接下来的 fail_timeout时间内，nginx不再将请求分发给失效的server。
比如失败3次，那么接下来10秒不会之内不会把请求发个这个认为失败的机器。然后过了30秒后，这个机器继续收到探测请求.一般生产中设置为30秒

upstream backend {

server 10.0.1.105:8080 weight=1 max_fails=3 fail_timeout=30s;

server 10.0.1.106:8080 weight=2 max_fails=3 fail_timeout=30s;

}

关于nginx反向代理功能由下面模块提供