请教一个 Nginx 配置的问题

背景：

1. 已签名 let's encrypt 证书
2. 已启动 vaultwarden/server docker 容器

需求：

1. 当访问 my_domain.com 或者 www.my_domain.com 时，响应对应的 index.html
2. 当访问 bitwarden.my_domain.com 时，展示对应的自建 bitwarden 服务

遇到的问题： 需求 1 - 正常，需求 2 - 页面报错，状态码 502

代码：

# etc/nginx/sites-available/my_domain.com server { root /var/www/my_domain.com/html; index index.html index.htm index.nginx-debian.html; server_name my_domain.com www.my_domain.com; location / { try_files $uri $uri/ =404; } listen [::]:443 ssl ipv6Only=on; # managed by Certbot listen 443 ssl; # managed by Certbot ssl_certificate /etc/letsencrypt/live/my_domain.com/fullchain.pem; # managed by Certbot ssl_certificate_key /etc/letsencrypt/live/my_domain.com/privkey.pem; # managed by Certbot include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot } server { if ($host = www.my_domain.com) { return 301 https://$host$request_uri; } # managed by Certbot if ($host = my_domain.com) { return 301 https://$host$request_uri; } # managed by Certbot listen 80; listen [::]:80; server_name my_domain.com www.my_domain.com; return 404; # managed by Certbot } server { listen 443 ssl http2; server_name bitwarden.my_domain.com; # Specify SSL config if using a shared one. #include conf.d/ssl/ssl.conf; include /etc/letsencrypt/options-ssl-nginx.conf; # Allow large attachments client_max_body_size 128M; location / { proxy_pass http://127.0.0.1:8087; proxy_http_version 1.1; proxy_cache_bypass $http_upgrade; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; 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_set_header X-Forwarded-Proto $scheme; proxy_set_header X-Forwarded-Host $host; proxy_set_header X-Forwarded-Port $server_port; } location /notifications/hub { proxy_pass http://127.0.0.1:3012; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; } location /notifications/hub/negotiate { proxy_pass http://127.0.0.1:8087; } location /admin { 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_set_header X-Forwarded-Proto $scheme; proxy_pass http://127.0.0.1:8087; } }