openresty用header_filter_by_lua设置自定义HTTP头

缺乏、安全感 2022-07-15 10:24 325阅读 0赞

**header\_filter\_by\_lua的说明：**

header_filter_by_lua
    
    syntax: header_filter_by_lua <lua-script-str>
    
    context: http, server, location, location if
    
    phase: output-header-filter
    
    WARNING Since the v0.9.17 release, use of this directive is discouraged; use the new header_filter_by_lua_block directive instead.
    
    Uses Lua code specified in <lua-script-str> to define an output header filter.
    
    Note that the following API functions are currently disabled within this context:
    
    Output API functions (e.g., ngx.say and ngx.send_headers)
    Control API functions (e.g., ngx.redirect and ngx.exec)
    Subrequest API functions (e.g., ngx.location.capture and ngx.location.capture_multi)
    Cosocket API functions (e.g., ngx.socket.tcp and ngx.req.socket).
    Here is an example of overriding a response header (or adding one if absent) in our Lua header filter:
    
     location / {
         proxy_pass http://mybackend;
         header_filter_by_lua 'ngx.header.Foo = "blah"';
     }
    This directive was first introduced in the v0.2.1rc20 release.

官网：[https://github.com/openresty/lua-nginx-module\#header\_filter\_by\_lua][https_github.com_openresty_lua-nginx-module_header_filter_by_lua]

**作用：**

a)新增自定义的HTTP头

b)重新设置upstream返回的HTTP头，也就是起到覆盖作用

**使用示范源码：nginx.conf**

worker_processes  1;
    error_log logs/error.log;
    events {
        worker_connections 1024;
    }
    
    http {
    
        log_format  main  '$msec $status $request $request_time '
                          '$http_referer $remote_addr [ $time_local ] '
                          '$upstream_response_time $host $bytes_sent '
                          '$request_length $upstream_addr';
    
        access_log  logs/access.log main buffer=32k flush=1s;
    
        upstream remote_world {
            server 127.0.0.1:8080;
        }
    
        server {
            listen 80;
    
            location /exec {
                content_by_lua '
                    local cjson = require "cjson"
                    local headers = {
                        ["Etag"] = "663b92165e216225df78fbbd47c9c5ba",
                        ["Last-Modified"] = "Fri, 12 May 2016 18:53:33 GMT",
                    }
                    ngx.var.my_headers = cjson.encode(headers)
                    ngx.var.my_upstream = "remote_world"
                    ngx.var.my_uri = "/world"
                    ngx.exec("/upstream")
                ';
            }
    
            location /upstream {
                internal;
    
                set $my_headers $my_headers;
                set $my_upstream $my_upstream;
                set $my_uri $my_uri;
                proxy_pass http://$my_upstream$my_uri;
    
                header_filter_by_lua '
                    local cjson = require "cjson"
                    headers = cjson.decode(ngx.var.my_headers)
                    for k, v in pairs(headers) do
                        ngx.header[k] = v
                    end
                ';
            }
        }
    
    
        server {
            listen 8080;
    
            location /world {
                echo "hello world";
            }
        }
    }

**运行：openresty -p \`pwd\` -c conf/nginx.conf**

**运行结果：**

![SouthEast][]

原文出自：[http://blog.csdn.net/daiyudong2020/article/details/53149242][http_blog.csdn.net_daiyudong2020_article_details_53149242]

End;

[https_github.com_openresty_lua-nginx-module_header_filter_by_lua]: https://github.com/openresty/lua-nginx-module#header_filter_by_lua
[SouthEast]: /images/20220715/0fd0a5b277204cd7a6f9e3f040972584.png
[http_blog.csdn.net_daiyudong2020_article_details_53149242]: http://blog.csdn.net/daiyudong2020/article/details/53149242