nginx lua 无法在重写前设置 headers

Question

我的 redis 服务器中有一组 IP 地址要被阻止。现在当客户端发出请求时，

请求必须被nginx拦截
检查remote_addr是否属于被屏蔽的ip
如果ip被封了加一个header
然后使用 request_uri.

nginx.conf

worker_processes  1;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;

    sendfile        on;

    keepalive_timeout  65;

    lua_shared_dict ip_status 1m;

    server {
        listen       9080;
        server_name  localhost;
        location ~ .* {
            rewrite_by_lua_file src/ip_check.lua;
        }
    }
}

src/ip_check.lua

-- redis configuration
local redis_host                = "127.0.0.1"
local redis_port                = 6379  -- connection timeouts for redis in ms.
local redis_max_idle_timeout    = 10000
local redis_pool_size           = 2     --  don't set this too high!
local redis_timeout             = 200

-- check a set with this key for blacklist entries
local redis_key         = ngx.var.remote_addr
local ip_status         = ngx.shared.ip_status
local status_unblocked  = "0"
local status_blocked    = "1"
-- cache lookups for this many seconds
local cache_ttl         = 1800

local redirect_host             = "http://192.168.12.103:8080/Spring4MVCHelloWorld1"
local header_ip_status_key      = "Ip-Status"
-- value of the header to be sent when the client ip address is blocked
local header_ip_status_value    = "block"
local add_header                = status_unblocked

-- lookup the value in the cache
local cache_result = ip_status:get(redis_key)
if cache_result then
  if cache_result == status_blocked then
    add_header = status_blocked
  end
else
  -- lookup against redis
  local resty = require "resty.redis"
  local redis = resty:new()
  redis:set_timeout(redis_timeout)

  local connected, err = redis:connect(redis_host, redis_port)
  if not connected then
    ngx.log(ngx.ERR, "ip_check: could not connect to redis @"..redis_host..":"..redis_port.." - "..err)
  else
    ngx.log(ngx.ALERT, "ip_check: found connect to redis @"..redis_host..":"..redis_port.." - successful")

    local result, err = redis:get(redis_key)
    if not result then
      ngx.log(ngx.ERR, "ip_check: lookup failed for "..ngx.var.remote_addr.." - "..err)
    else
      if result == status_blocked then
        add_header = status_blocked
      end

      -- cache the result from redis
      ip_status:set(ip, add_header, cache_ttl)
    end

    redis:set_keepalive(redis_max_idle_timeout, redis_pool_size)
  end
end

ngx.log(ngx.ALERT, "ip_check: "..header_ip_status_key.." of "..ngx.var.remote_addr.." is "..add_header)
if add_header == status_blocked then
    ngx.header[header_ip_status_key] = header_ip_status_value
    ngx.req.set_header(header_ip_status_key, header_ip_status_value)
end

ngx.redirect(redirect_host..ngx.var.request_uri)

出于测试目的，我将 127.0.0.1 键添加到 redis，值为 1。因此，应该使用附加的 header 命中重定向 uri。我面临的问题是无论我使用 ngx.header 还是 ngx.req.set_header Ip-Status header 都不会发送到重定向请求和结束 api 没有收到它。

例如，如果我在浏览器中点击 http://localhost:9080/hello，

请求headers

Host:"localhost:9080"
User-Agent:"Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:46.0) Gecko/20100101 Firefox/46.0"
Accept:"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
Accept-Language:"en-US,en;q=0.5"
Accept-Encoding:"gzip, deflate"
Connection:"keep-alive"

回复headers

Connection:"keep-alive"
Content-Length:"166"
Content-Type:"text/html"
Date:"Thu, 05 May 2016 08:06:33 GMT"
Location:"http://192.168.12.103:8080/Spring4MVCHelloWorld1/hello"
Server:"openresty/1.9.7.2"
ip-status:"block"

重定向的 uri 是 http://localhost:9080/hello,

请求headers

Host:"192.168.12.103:8080"
User-Agent:"Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:46.0) Gecko/20100101 Firefox/46.0"
Accept:"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
Accept-Language:"en-US,en;q=0.5"
Accept-Encoding:"gzip, deflate"
Cookie:"JSESSIONID=4834843FE0E76170E429028E096A66E5"
Connection:"keep-alive"

回复headers

Content-Language:"en-US"
Content-Length:"166"
Content-Type:"text/html;charset=UTF-8"
Date:"Thu, 05 May 2016 08:06:33 GMT"
Server:"Apache-Coyote/1.1"

我能够在原始请求的 header 响应中看到 Ip-Status header，但在请求中看不到 headers 重定向的 uri。关于如何将 header 发送到重定向的 uri 的任何帮助都将非常有帮助。

我是 nginx 和 lua 的新手。提问是因为我找不到任何相应的问题，如果问题已经被问到，我深表歉意。

Answer 1

浏览器重定向到重定向的 uri，nginx 无法控制 headers。所以，我删除了

ngx.redirect(redirect_host..ngx.var.request_uri)

从 src/ip_check.lua 更改 nginx.conf 进行代理调用，我能够观察到 api 能够接收额外的 header.

已修改nginx.conf

worker_processes  1;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;

    sendfile        on;
    keepalive_timeout  65;
    lua_shared_dict ip_status 1m;

    server {
        listen       9080;
        server_name  localhost;
        location ~ .* {
            set $backend_host   "http://192.168.12.103:8080/Spring4MVCHelloWorld1";
            access_by_lua_file src/ip_check.lua;
            proxy_pass $backend_host$request_uri;
        }
    }
}

修改后的 nginx.conf 将向 $backend_host$request_uri 发出请求，浏览器将不知道所做的重定向.因此，在进行代理调用时，将发送 ngx.req.set_header 设置的 header。所以，

ngx.header[header_ip_status_key] = header_ip_status_value

也可以从 src/ip_check.lua.

中删除

nginx lua 无法在重写前设置 headers

nginx lua not able to set headers before rewrite

redirect

nginx

lua

openresty