自定义HTTP头时的注意事项
HTTP头是可以包含英文字母([A-Za-z])、数字([0-9])、连接号(-)hyphens, 也可义是下划线(_)。在使用nginx的时候应该避免使用包含下划线的HTTP头。主要的原因有以下2点。
1.默认的情况下nginx引用header变量时不能使用带下划线的变量。要解决这样的问题只能单独配置underscores_in_headers on。
2.默认的情况下会忽略掉带下划线的变量。要解决这个需要配置ignore_invalid_headers off。
当然，nginx设置变量的时候是没有任何这样的限制的，可以直接设置带下划线的header。但是最好不要这样做。在使用nginx做多级代理的时候，也需要注意一些header不要重复设置。比如用来保存用户IP的这个header只在最上层的nginx里配置就行，后面的nginx不要重复设置导致覆盖。
简单测试一下多个nginx做代理的时候处理的思路,为了方便我就直接在一个nginx上跑多个server测试
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
log_format main ‘$http_orig_client_ip – $remote_addr – $remote_user [$time_local] "$request" ‘
‘$status $body_bytes_sent "$http_referer" ‘
‘"$http_user_agent" "$http_x_forwarded_for" "$upstream_addr" ‘;
sendfile on;
underscores_in_headers on;
ignore_invalid_headers off;
keepalive_timeout 65;
upstream test2081{
server 10.209.128.28:2081;
}
upstream test2082{
server 10.209.128.28:2082;
}
upstream test2083{
server 10.209.128.28:80;
}
server {
listen 2080;
server_name localhost;
access_log logs/access80.log main;
location / {
root html;
proxy_set_header ORIG_CLIENT_IP $remote_addr;
proxy_set_header Host $http_host;
proxy_set_header X-Forwarded-By $server_addr:$server_port;
proxy_set_header X-Forwarded-For $http_x_forwarded_for;
proxy_pass http://test2081;
}
}
server {
listen 2081;
server_name localhost;
access_log logs/access81.log main;
location / {
root html;
proxy_set_header Host $http_host;
proxy_set_header X-Forwarded-By $server_addr:$server_port;
proxy_set_header X-Forwarded-For $http_x_forwarded_for;
proxy_pass http://test2082;
}
}
server {
listen 2082;
server_name localhost;
access_log logs/access82.log main;
location / {
root html;
proxy_set_header Host $http_host;
proxy_set_header X-Forwarded-By $server_addr:$server_port;
proxy_set_header X-Forwarded-For $http_x_forwarded_for;
proxy_pass http://test2083;
}
}
}
==> logs/access80.log <==
– – 10.210.208.47 – – [29/Mar/2013:20:18:43 +0800] "GET / HTTP/1.1" 200 52873 "-" "curl/7.15.5 (x86_64-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5" "-" "10.209.128.28:2081"
==> logs/access81.log <==
10.210.208.47 – 10.209.128.28 – – [29/Mar/2013:20:18:43 +0800] "GET / HTTP/1.0" 200 52873 "-" "curl/7.15.5 (x86_64-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5" "-" "10.209.128.28:2082"
==> logs/access82.log <==
10.210.208.47 – 10.209.128.28 – – [29/Mar/2013:20:18:43 +0800] "GET / HTTP/1.0" 200 52873 "-" "curl/7.15.5 (x86_64-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5" "-" "10.209.128.28:80"
server 2080收到请求后会设置一个不规范的HTTP头，后面连接了2段server。发起请求后,日志如下
可以看到2081和2082的都是能正确传递好这个header的（包括机器上80端口跑的也是可以的）。