TLDR：myurl 转换 subweb 的订阅长链接报 502 ，转换其他链接能正常跳转

起因

最近想自建短链，看到了 stilleshan 的项目，作者提供了完整的指南和配置文件，想着搭一个玩玩。根据作者的 docker-compose 文件，nginx 配置文件搭建好之后，尝试转换 subweb 的订阅链接，能转换成功返回短链，数据库也成功存储长链接数据，但通过短链访问长链确报 502 的错误，转换 Google ，bing 上别的网站的长链接能够正常跳转，甚至是作者自己搭建的短链也成功跳转（我的短链-->作者的短链-->长链），这让我非常困惑。

背景

域名在 cloudflare 上托管着，用的 nginx 做反向代理

排查

nginx

正常，可以接收短链的请求，有访问日志

ip.ip.ip.ip - - [30/Nov/2022:15:58:16 +0000] "GET /gpx3R8g HTTP/2.0" 502 559 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36 Edg/107.0.1418.56" "ip.ip.ip.ip" 

配置文件如下

server { listen 80; server_name a.b.c; return 301 https://a.b.c$request_uri; } server { listen 443 ssl http2; server_name a.b.c; index index.php index.html index.htm default.php default.htm default.html; ssl_certificate /etc/nginx/ssl/a.b.c/fullchain1.pem; ssl_certificate_key /etc/nginx/ssl/a.b.c/privkey1.pem; gzip on; ssl_stapling on; ssl_stapling_verify on; ssl_protocols TLSv1.1 TLSv1.2 TLSv1.3; ssl_prefer_server_ciphers on; ssl_ciphers ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA:ECDHE-RSA-AES128-SHA:ECDHE-RSA-DES-CBC3-SHA:AES256-GCM-SHA384:AES128-GCM-SHA256:AES256-SHA256:AES128-SHA256:AES256-SHA:AES128-SHA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!MD5:!PSK:!RC4; ssl_ecdh_curve secp384r1; ssl_session_timeout 10m; ssl_session_cache builtin:1000 shared:SSL:10m; ssl_session_tickets off; resolver 8.8.8.8 8.8.4.4 valid=60s ipv6=off; resolver_timeout 5s; add_header Strict-Transport-Security "max-age=63072000" always; location / { proxy_redirect off; # proxy_http_version 1.1; proxy_pass http://a.b.c:8002; add_header 'Access-Control-Allow-Origin' '*'; proxy_set_header Host $http_host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-Ssl on; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Forwarded-Proto $scheme; proxy_set_header X-Frame-Options SAMEORIGIN; client_max_body_size 100m; client_body_buffer_size 128k; } # Pass PHP files to FPM. # location ~ \.php$ { # try_files $uri =404; # fastcgi_split_path_info ^(.+\.php)(/.+)$; # fastcgi_pass unix:/var/run/php5-fpm.sock; # fastcgi_index index.php; # include fastcgi_params; # } # Deny hidden files. location ~ /\. { deny all; } # Forbidden files or directories location ~ ^/(\.user.ini|\.htaccess|\.git|\.svn|\.project|LICENSE|README.md) { return 404; } # Directory verification related settings for one-click application for SSL certificate location ~ \.well-known { allow all; } location ~ .*\.(gif|jpg|jpeg|png|bmp|swf)$ { expires 30d; error_log /dev/null; access_log off; } location ~ .*\.(js|css)?$ { expires 12h; } access_log /var/log/nginx/a.b.c.access.log main; error_log /var/log/nginx/a.b.c.error.log warn; } 

redis

正常，可以存储长链和短链

前端

正常，可以正确解析长链，返回短链

疑惑

目前将问题定位在 cloudflare 上，但 cloudflare 免费版能设置的也就零星几个选项，想知道该怎么设置才能解除报 502 ，正常跳转到长链接