server 上下文

server {
}

server指令用于配置一个虚拟服务。listen指令描述了本服务可接受链接的所有地址和端口，server_name指令列举了所有服务的名字，例如

server {listen      80;server_name example.org www.example.org;
}

listen 指令

Syntax:	
listen address[:port] [default_server] [ssl] [http2 | quic] [proxy_protocol] [setfib=number] [fastopen=number] [backlog=number] [rcvbuf=size] [sndbuf=size] [accept_filter=filter] [deferred] [bind] [ipv6only=on|off] [reuseport] [so_keepalive=on|off|[keepidle]:[keepintvl]:[keepcnt]];listen port [default_server] [ssl] [http2 | quic] [proxy_protocol] [setfib=number] [fastopen=number] [backlog=number] [rcvbuf=size] [sndbuf=size] [accept_filter=filter] [deferred] [bind] [ipv6only=on|off] [reuseport] [so_keepalive=on|off|[keepidle]:[keepintvl]:[keepcnt]];listen unix:path [default_server] [ssl] [http2 | quic] [proxy_protocol] [backlog=number] [rcvbuf=size] [sndbuf=size] [accept_filter=filter] [deferred] [bind] [so_keepalive=on|off|[keepidle]:[keepintvl]:[keepcnt]];Default:	listen *:80 | *:8000;
Context:	server

例如一些常见的用法，listen指令指定了该服务监听的地址和端口

listen 127.0.0.1:8000;
listen 127.0.0.1;	# 不加端口，默认80
listen 8000;
listen *:8000;
listen localhost:8000;#IPv6 addresses
listen [::]:8000;
listen [::1];

server_name 指令

Syntax:	server_name name ...;
Default:	
server_name "";
Context:	server

设置虚拟服务的名字，可以使用通配符和正则表达式

server_name example.com www.example.com;server_name example.com *.example.com www.example.*;server_name www.example.com ~^www\d+\.example\.com$;

多服务请求处理

当有多个服务时，nginx如何决定使用哪个server进行处理呢？例如在*:80端口监听了多个服务：

server {listen 80 default_server;server_name test.com;default_type text/html;location / {return 200 'Default Main Server\n';}
}server {listen 80;server_name zh.test.com;default_type text/html;location / {return 200 'Chinese Server\n';}
}server {listen 80;server_name en.test.com;default_type text/html;location / {return 200 'English Server\n';}
}

nginx 将通过测试请求头中的Host字段来决定使用哪个服务。如果没有server name 被匹配到，或者请求中不包含请求头，则使用该端口的默认服务。listen指令中的default_server可以用来显式配置默认服务，如果没有该字段，那么默认使用该端口的第一个服务。

使用curl请求测试，分别得到

$ curl -H ‘Host: test.com' -v localhost 
Default Main Server
$ curl -H ‘Host: zh.test.com' -v localhost 
Chinese Server
$ curl -H ‘Host: en.test.com' -v localhost 
English Server

name-based 和 IP-based混合虚拟服务

服务器可以有多个公网IP以及解析多个域名，如下配置：

server {listen 127.0.0.2:80;server_name test.com;default_type text/html;location / {return 200 'Default Main Server\n';}
}server {listen 127.0.0.1:80;server_name zh.test.com;default_type text/html;location / {return 200 'Chinese Server\n';}
}server {listen 127.0.0.1:80;server_name en.test.com;default_type text/html;location / {return 200 'English Server\n';}
}

访问测试：

$ curl -H 'Host: test.com' -v 127.0.0.1
Chinese Server
$ curl -H 'Host: test.com' -v 127.0.0.2
Default Main Server
$ curl -H 'Host: zh.test.com' -v 127.0.0.1
Chinese Server
$ curl -H 'Host: zh.test.com' -v 127.0.0.2
Default Main Server