Nginx直接处理接口请求，返回相应内容，带html标签

停服业务需要，服务器更新升级时，有时候需要维护一段时间，这段时间内，为了保证用户体验，通常都会在app端展示维护信息，和维护时间等等，

下面是一种app停服方案：

Nginx中编码，提供一个接口，app客户端每次登录前都会先请求这个接口，这个接口如果返回服务器已经停服，那么就根据返回值中的维护信息进行展示，

接口如下图：

server {
        server_name  192.168.19.218;
        listen 80;
                
                # 导入停服配置
                include maintenance/serviceInfo.conf;
                
                # 服务状态接口
                location /service_info {
                        default_type "application/json;charset=UTF-8";
                        if ($service_status = "NORMAL") {
                                return 200 '{"service_status":"NORMAL","maintenance_begin_time":"","maintenance_end_time":"","maintenance_intro":""}'; 
                        }
                        if ($service_status = "WAIT_STOP") {
                                return 200 '{"service_status":"WAIT_STOP","maintenance_begin_time":"$maintenance_begin_time","maintenance_end_time":"$maintenance_end_time","maintenance_intro":"$maintenance_intro"}'; 
                        }
                        if ($service_status = "STOP") {
                                return 200 '{"service_status":"STOP","maintenance_begin_time":"$maintenance_begin_time","maintenance_end_time":"$maintenance_end_time","maintenance_intro":"$maintenance_intro"}'; 
                        }
                }
                
                # 访问后端接口
        location /
        {
                        # 若停服，则直接以503的错误码返回
                        if ($service_status = "STOP") {
                                return 503 '{"code": "503", "message": "停服更新中!"}';
                        }
                        add_header Access-Control-Allow-Origin "*";
                        add_header Access-Control-Allow-Credentials "true";
                        add_header Cache-Control no-cache,private;
                        add_header Access-Control-Allow-Methods GET,POST,PUT,DELETE,PATCH,OPTIONS;
                        add_header Access-Control-Allow-Headers Origin,X-Requested-With,Content-Type,Accept,authorization,bysyskey;
            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_pass http://apiserver;
            #proxy_http_version 1.1;
            #proxy_set_header Connection "";
        }
    }

maintenance/serviceInfo.conf 配置停服信息

# 服务状态，NORMAL：正常，WAIT_STOP：待停服，STOP：停服
set $service_status NORMAL;
# 维护开始时间
set $maintenance_begin_time 1627530630000;
# 维护结束时间
set $maintenance_end_time 1627530630010;
# 维护内容：
set $maintenance_intro '<h3><span class=\\"ql-size-large\\">停服维护公告</span></h3><p>1、修复BUG</p><p>2、<span color: rgb(230, 0, 0);\\">增加关卡</span></p><p><br></p>';