nginx如何根据报文里字段转发至不同地址

sudo apt-get update
sudo apt-get install -y curl gnupg2 ca-certificates lsb-release ubuntu-keyring
curl -O https://openresty.org/package/pubkey.gpg
sudo apt-key add pubkey.gpg
sudo apt-get install -y apt-transport-https
echo "deb https://openresty.org/package/debian $(lsb_release -sc) openresty" | sudo tee /etc/apt/sources.list.d/openresty.list
sudo apt-get update
sudo apt-get install -y openresty

http {
    lua_package_path "/usr/local/openresty/luajit/share/lua/5.1/?.lua;;";
    lua_shared_dict my_cache 10m;
    server {
        listen 80;
        location / {
            content_by_lua_block {
                -- 读取 POST 请求体
                ngx.req.read_body()
                local data = ngx.req.get_body_data()
                if not data then
                    ngx.status = ngx.HTTP_BAD_REQUEST
                    ngx.say("No request body found")
                    return ngx.exit(ngx.HTTP_BAD_REQUEST)
                end
                -- 解析 JSON
                local cjson = require "cjson.safe"
                local json_data = cjson.decode(data)
                if not json_data or not json_data.id then
                    ngx.status = ngx.HTTP_BAD_REQUEST
                    ngx.say("Invalid JSON or missing 'id' field")
                    return ngx.exit(ngx.HTTP_BAD_REQUEST)
                end
                local id = json_data.id
                local target_url
                if id == "aaa" then
                    target_url = "http://www.aaa.com.test"
                elseif id == "bbb" then
                    target_url = "http://www.bbb.com.test"
                else
                    ngx.status = ngx.HTTP_NOT_FOUND
                    ngx.say("Unknown 'id' value")
                    return ngx.exit(ngx.HTTP_NOT_FOUND)
                end
                -- 创建 HTTP 客户端并转发请求
                local http = require "resty.http"
                local httpc = http.new()
                local res, err = httpc:request_uri(target_url, {
                    method = ngx.var.request_method,
                    body = data,
                    headers = ngx.req.get_headers(),
                    keepalive = false,
                })
                if not res then
                    ngx.status = ngx.HTTP_INTERNAL_SERVER_ERROR
                    ngx.say("Failed to forward request: ", err)
                    return ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
                end
                -- 设置响应头
                for k, v in pairs(res.headers) do
                    ngx.header[k] = v
                end
                -- 发送响应体
                ngx.status = res.status
                ngx.print(res.body)
                -- 关闭 HTTP 客户端
                httpc:close()
            }
        }
    }
}

sudo systemctl restart nginx