Nginx location优先级匹配原则

1. 带有“=”前缀的指令与查询完全匹配。如果找到，搜索停止
2. 所有其余指令与传统的字符串。如果此匹配使用“^〜”前缀，则停止搜索
3. 正则表达式，按照它们在配置文件中定义的顺序
4. 如果＃3产生匹配，则使用该结果。否则，使用来自＃2的匹配


location  = / {
  # matches the query / only.
  [ configuration A ] 
}
location  / {
  # matches any query, since all queries begin with /, but regular
  # expressions and any longer conventional blocks will be
  # matched first.
  [ configuration B ] 
}
location /documents/ {
  # matches any query beginning with /documents/ and continues searching,
  # so regular expressions will be checked. This will be matched only if
  # regular expressions don't find a match.
  [ configuration C ] 
}
location ^~ /images/ {
  # matches any query beginning with /images/ and halts searching,
  # so regular expressions will not be checked.
  [ configuration D ] 
}
location ~* \.(gif|jpg|jpeg)$ {
  # matches any request ending in gif, jpg, or jpeg. However, all
  # requests to the /images/ directory will be handled by
  # Configuration D.   
  [ configuration E ] 
}