如何在兩層伺服器的第二層Nginx上取得使用者IP
一.之前在做nginx的伺服器設定的時候遇到了一個問題,在之前伺服器有用到一個限制客戶端最大並發連線的功能,而且這個功能的實作是依靠在伺服器中做
$remote-addr
這樣的設定來達到的。但在增加了前端一層(負載、CDN、防火牆、安全服務)伺服器之後,拿到的客戶端IP就都變成了前端伺服器的IP,但並非真是真是的用戶IP位址。
二.這樣的問題下,我又重新看了幾次nginx官網的介紹,也發現其中另外一個特別重要的變數
$proxy_add_x_forwarded_for
這個變數是客戶端存取請求中的X-forwarded-for 欄位的值,如果請求中不包含這個字段,則自動用這個變數會等價於remote-addr這個變數。這允許我們獲取HTTP請求中通常情況下前端伺服器保存的客戶真實IP位址的字段,通常就是我們說的X_FORWARDED_FOR字段,然後透過這樣的方法,我們就可以實現各種各樣的功能了。
三.下面我來實際為大家做一個簡單示範。諸多不足,歡迎指正。
首先我們先搭建好Nginx的環境,這裡我們使用1.7 系列的最新版本1.7.9為例,(關於版本的問題請參考FAQ 1)
下載、WGET所需網址http://nginx.org/ download/nginx-1.7.9.tar.gz
1. 下載Nginx
[lugt@localhostmysql]$ wget http://nginx.org/download/nginx-1.7.9.g
[lugt@localhostmysql]$ tar zxvf nginx-1.7.9.tar.gz
3. 直接編譯(需考慮是否需要openssl等外掛程式的支援)
[mydft點🕎 9
[lugt@localhost nginx-1.7.9]$ ./configure
[lugt@localhost nginx-1.7.9]$ make
[lugt@localhost nginx-1.7.9]$ su localhostnginx-1.7.9]$ make install
4. 接著接下來修改nginx.conf設定檔
[lugt@localhost nginx-1.7.9]$ su
[lugt@localhost nginx-1.7.9]$ suhost
/usr/local/nginx[lugt@localhostnginx]$ vi conf/nginx.conf然後在nginx.conf 中找到這裡,加入來設定負載均衡,模仿CDNupstream dnsnginx1 { server[*.*.*.*/yourhostname]:8080 weight=10000; #填IP、域名 } server { listen 80; server_name #access_log logs/host.access.log main location /{ proxy_pass http://dnsnginx1; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header HTTP_X_FORWARDED_FOR $remote_addr; proxy_redirect default; } }
在設定一個虛擬伺服器在8080端口,
limit_conn_zone $proxy_add_x_forwarded_for zone=addr:10m; # 并发设置 空间10M server { listen 8080; server_name [*.*.*.*/yourhostname]:8080 weight=10000; #填IP、域名 limit_conn addr 1; #限制客户端最大并发连接数为 1 location / { root html; index index.html index.htm; } }
使用ab 工具查看效果。
[lugt@localhost nginx]$ ab –c 10 –n 100 –v 4 http://127.0.0.1/ | grep HTTP/1.1
這行的意思:透過AB測試工具存取位址,並發連線數為30,總測試300次,顯示HTTP返回頭資訊
透過ab 工具可以測出無論同時發送多少連接,最後成功返回200的只有之前限制nginx的最大並發連接數,所以可以證明對於IP的限制功能已經可以使用了。參考資料請見FAQ2
FAQ 1 版本問題
如果目前正在使用的Nginx版本沒有達到1.7.1版本,很可能nginx還不支援這個功能,
這時候就需要透過一段程式碼夾在limit_conn_handler函數中來從request取得x_forwarded_for 的值。
以1.6.1版本為例,程式碼增加如下。 src/http/modules/ngx_http_limit_conn.c 第184行
hash =ngx_crc32_short(key.data, key.len); If(“” == &ctx->key){ <span style="white-space:pre"> </span>If(NULL!= r->main->headers_in->x_forwarded_for->elts){ key.data= *(char*)r->main->headers_in->x_forwarded_for->elts; key.len = 4; hash =ngx_crc32_short(key.data, key.len); <span style="white-space:pre"> </span>} }
這裡是一份參考數據, 獲取
[lugt@localhost~]$ ab -c 10 -n 100 -v 4 http://127.0.0.1/ | grep HTTP/1.1
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
503 Service Temporarily UnavailableHTTP/1.1 200 OKHTTP/ 1.1503 Service Temporarily UnavailableHTTP/1.1503 Service Temporarily UnavailableHTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1 200 OK
<… repeated 往下均为重复8次HTTP/503 与1次HTTP/200 交替出现>
English Version
How to retrievethe true ip of the client user if there are two layers of servers
Days before, wehave been faced such a difficulty which is we can’t use the variable $remote_addr for gathering the clients’ip address. This problem surfaces when we used a proxy server between the trueserver and client, which is actually a cdn. And that makes our functions oflimiting the maximum connections a client can make to a server at a time. Thissituation can also found if the load balance or any anti-spam service are inuse. So that’s why we can’t use remote_addr variable further.
After I did someresearch on the documentation and the code , I found out that this problem canbe solved by replacing the
$remote_addr
$proxy_add_x_forwarded_for
And now I shall makean easy example to practically use this method.
First of all,build up a Nginx server.
Here, I will usethe 1.7.9 version (latest to the written time) for instance, therefore, thereexist some differences between older versions than 1.7.1 (see FAQ 1)
1. Download A Nginx Copy:
[lugt@localhostmysql]$ wget http://nginx.org/download/nginx-1.7.9.tar.gz
2. Decompress the file
[lugt@localhostmysql]$ tar zxvf nginx-1.7.9.tar.gz
3. Compile The Code
[lugt@localhostmysql]$ cd nginx-1.7.9
[lugt@localhostnginx-1.7.9]$ ./configure
[lugt@localhostnginx-1.7.9]$ make
[lugt@localhostnginx-1.7.9]$ su
[lugt@localhostnginx-1.7.9]$ make install
4. And edit the config file nginx.conf
[lugt@localhost nginx-1.7.9]$ su
[lugt@localhostnginx-1.7.9]$ cd /usr/local/nginx
[lugt@localhostnginx]$ vi conf/nginx.conf
There add suchdirectives to the server1 for emulate for an CDN server
upstream dnsnginx1 { server[*.*.*.*/yourhostname]:8080 weight=1000; #fill in your ip/hostname } server { listen 80; server_name [hostname] #fill your ip/ hostname here #access_log logs/host.access.log main location /{ proxy_pass http://dnsnginx1; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header HTTP_X_FORWARDED_FOR $remote_addr; proxy_redirect default; } }
After the end ofone server directive, and in the http directive, add so to function the sever2
limit_conn_zone $proxy_add_x_forwarded_for zone=addr:10m; # sample setting server { listen 8080; server_name [*.*.*.*/hostname]:8080 weight=10000; #fill in ip/hostname here limit_conn addr 1; # Enablethe limitation of connection per ip at a time to 1. location / { root html; index index.html index.htm; } }
And then you cansave , test the config file and run nginx
Test your configfile:
[lugt@localhostnginx]$ ./sbin/nginx –t
Start the nginx server
[lugt@localhostnginx]$ ./sbin/nginx
Now, the serverhas been set and you can run a test at instance.
/* This CommandMeans to run a tool to connect to server as 10conn/once and 10 conns in total*/
[lugt@localhost~]$ ab -c 10 -n 100 -v 4 http://127.0.0.1/ | grep HTTP/1.1
FAQ 1
There is actuallysome little malfunctions when using elder versions than 1.7.1 (Probably the newversion has it for a new feature).So to use this directive in earlier versions,some code need to be added.
As a Example inthe version 1.6.1
In filesrc/http/modules/ngx_http_limit_conn.c Line around 184
hash =ngx_crc32_short(key.data, key.len); If("" == &ctx->key){ If(NULL!= r->main->headers_in->x_forwarded_for->elts){ key.data= *(char*)r->main->headers_in->x_forwarded_for->elts; key.len = 4; hash =ngx_crc32_short(key.data, key.len); }
}<span style="font-family: Arial, Helvetica, sans-serif;"> </span>
FAQ 2 TestingResults
[lugt@localhost~]$ ab -c 10 -n 100 -v 4 http://127.0.0.1/ | grep HTTP/1.1
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1 200 OK
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
HTTP/1.1503 Service Temporarily Unavailable
503 Service Temporarily UnavailableHTTP/1.1503 Service Temporarily UnavailableHTTP /1.1503 Service Temporarily UnavailableHTTP/1.1503 Service Temporarily UnavailableHTTP/1.1503 Service Temporarily UnavailableHTTP/1.1503 Service Temporarily UnavailableHTTP/1。 time of HTTP/200 and so on>以上就介紹如何在兩層伺服器的第二層Nginx上取得使用者IP,包含了方面的內容,希望對PHP教學有興趣的朋友有所幫助。