Nginx 关于 Rewrite 的迭代 第二篇例题 1配置：error_log logs/error.log info; server { listen 9090; server_name localhost; root html; rewrite_log on; rewrite "^/aaa\.html$" /bbb.html; location /ccc.html { rewrite "^/ccc\.html$" /eee.html; } location /bbb.html { rewrite "^/bbb\.html$" /ccc.html; rewrite "^/ccc\.html$" /ddd.html; } } 结果： [root@web108 ~]# curl http://localhost:9090/aaa.html ddd html file [root@web108 ~]# 日志： 2011/08/08 10:05:41 [notice] 31592#0: *90 "^/aaa\.html$" matches "/aaa.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:05:41 [notice] 31592#0: *90 rewritten data: "/bbb.html" , args: "", client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:05:41 [notice] 31592#0: *90 "^/bbb\.html$" matches "/bbb.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:05:41 [notice] 31592#0: *90 rewritten data: "/ccc.html" , args: "", client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:05:41 [notice] 31592#0: *90 "^/ccc\.html$" matches "/ccc.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:05:41 [notice] 31592#0: *90 rewritten data: "/ddd.html" , args: "", client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:05:41 [notice] 31592#0: *90 "^/aaa\.html$" does not match "/ddd.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:05:41 [info] 31592#0: *90 client 127.0.0.1 closed keepalive connection 解释： GET /aaa.html 请求，首先执行 server 级的 rewrite 指令，被重写为 /bbb.html ，然后匹配到 location /bbb.html {}，接着执行 location 级的 rewrite 指令，先重写为 /ccc.html ，再重写为 /ddd.html ；由于 URI 被 location 级的rewrite 指令重写了，因此需要重新进行 location 的匹配，相当于重写后的 URI 被当做一个新的请求，会重新执行server 级的 rewrite ，然后重新匹配 location ，日志“ 2011/08/08 10:05:41 [notice] 31592#0: *90 "^/aaa\.html$" does not match "/ddd.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" ”体现了重新匹配 location 的流程。 例题 2配置：error_log logs/error.log info; server { listen 9090; server_name localhost; root html; rewrite_log on; rewrite "^/aaa\.html$" /bbb.html; rewrite "^/ccc\.html$" /ddd.html; location /bbb.html { rewrite "^/bbb\.html$" /ccc.html; } location /ddd.html { rewrite "^/ddd\.html$" /eee.html; } } 结果： [root@web108 ~]# curl http://localhost:9090/aaa.html eee html file [root@web108 ~]# 日志： 2011/08/08 10:21:00 [notice] 2218#0: *91 "^/aaa\.html$" matches "/aaa.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 rewritten data: "/bbb.html" , args: "", client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 "^/ccc\.html$" does not match "/bbb.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 "^/bbb\.html$" matches "/bbb.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 rewritten data: "/ccc.html" , args: "", client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 "^/aaa\.html$" does not match "/ccc.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 "^/ccc\.html$" matches "/ccc.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 rewritten data: "/ddd.html" , args: "", client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 "^/ddd\.html$" matches "/ddd.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 rewritten data: "/eee.html" , args: "", client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 "^/aaa\.html$" does not match "/eee.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [notice] 2218#0: *91 "^/ccc\.html$" does not match "/eee.html" , client: 127.0.0.1, server: localhost, request: "GET /aaa.html HTTP/1.1", host: "localhost:9090" 2011/08/08 10:21:00 [info] 2218#0: *91 client 127.0.0.1 closed keepalive connection 解释： 第一次迭代 location 匹配 GET /aaa.html ，首先执行 server 级的重写，“ rewrite "^/aaa\.html$" /bbb.html ”把 /aaa.html 重写为 /bbb.html ，但 /bbb.html 没匹配上“ rewrite "^/ccc\.html$" /ddd.html ”，最终保留 /bbb.html ；接着，匹配 location /bbb.html {}，执行 location 级的 rewrite 指令，把 /bbb.html 重写为 /ccc.html ，由于 URI 被 location 级 rewrite 重写，因此需要重新迭代 location 匹配。 第二次迭代 location 匹配 对于第一次迭代结果 /ccc.html ，首先依然是执行 server 级的 rewrite 指令，“ rewrite "^/aaa\.html$" /bbb.html; ”跟/ccc.html 不匹配，但“ rewrite "^/ccc\.html$" /ddd.html; ”把 /ccc.html 重写为 /ddd.html ； server 级 rewrite 执行完后，接着 location 匹配， /ddd.html 匹配到 location /ddd.html {} ，执行 location 级的 rewrite 指令，把 /ddd.html重写为 /eee.html 。同样由于 URI 被 location 级的 rewrite 指令重写，于是需要重新迭代 location 匹配。 第三次迭代 location 匹配 对于第二次迭代结果 /eee.html ，首先依然执行 server 级的 rewrite 指令，“ rewrite "^/aaa\.html$" /bbb.html; ”和“rewrite "^/ccc\.html$" /ddd.html; ”，只不过它们都没匹配上 /eee.html ，接着 /eee.html 进行 location 匹配，也没有，最终结果是 /eee.html ，返回“ eee html file ”页面。 最后说明下，如果把上述配置修改成server级rewrite和location的编辑顺序调整： server { listen 9090; server_name localhost; root html; rewrite_log on; location /bbb.html { rewrite "^/bbb\.html$" /ccc.html; } location /ddd.html { rewrite "^/ddd\.html$" /eee.html; } rewrite "^/aaa\.html$" /bbb.html; rewrite "^/ccc\.html$" /ddd.html; } 结果是不会受影响的，也就是说location匹配迭代总是先执行server级rewrite，再进行location匹配，再执行location级的rewrite，如果URI因location级rewrite指令重写，则需要进行下一次迭代。但总的迭代次数不超过10次，否则nginx报500错误。 简单伪代码描述下rewrite执行过程： boolean match_finish = false; int match_count = 0; while(!match_finish && match_count < 10) { match_count ++; （1）按编辑顺序执行server级的rewrite指令； （2）按重写后的URI匹配location； （3） String uri_before_location = uri; 按编辑顺序执行location级的rewrite指令； String uri_after_location = rewrite(uri); if(uri_before_location != uri_after_location) { match_finish = false; } else { match_finish = true; } if(location rewrite has last flag) { continue;//表示不执行后面的rewrite，直接进入下一次迭代 } if(location rewrite has break flag) { break;//表示不执行后面的rewrite，并退出循环迭代 } } if(match_count <= 10) { return HTTP_200; } else { return HTTP_500; } (责任编辑：IT) |