I haven't had any issues with my Docker container or NGINX until today where I am getting a random unexpected 502 Bad Gateway error even though I have made no changes to my configuration files, Docker files, or any other file in my project.
The 502 error from /var/log/nginx/reverse-access.log:
9.160.81.63 - - [25/Mar/2022:20:40:50 +0000] "GET /api/get_info HTTP/1.1" 502 559 "https://example.com:4000/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.82 Safari/537.36" The error message from /var/log/nginx/reverse-error.log:
[error] 26#26: *6 connect() failed (111: Connection refused) while connecting to upstream, client: 9.160.81.63, server: , request: "GET /api/get_info HTTP/1.1", upstream: "https://0.0.0.0:5000/api/get_info", host: "example.com:4000", referrer: "https://example.com:4000/" /etc/nginx/conf.d/default.conf:
server { listen 8765 ssl default_server; root /usr/share/nginx/html; index index.html index.html; ssl_certificate /etc/ssl/certs/example_project/cert.pem; ssl_certificate_key /etc/ssl/certs/example_project/key.pem; ssl_dhparam /etc/ssl/certs/example_project/dhparam.pem; ssl on; ssl_session_cache builtin:1000 shared:SSL:10m; ssl_protocols TLSv1 TLSv1.1 TLSv1.2; ssl_ciphers HIGH:!aNULL:!eNULL:!EXPORT:!CAMELLIA:!DES:!MD5:!PSK:!RC4; ssl_prefer_server_ciphers on; ssl_session_timeout 60m; access_log /var/log/nginx/reverse-access.log; error_log /var/log/nginx/reverse-error.log; location / { try_files $uri /index.html =404; } location /api { proxy_pass https://0.0.0.0:5000/api; proxy_redirect default; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; proxy_set_header Host $host:4000; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Forwarded-Host $server_name; } } This is all running on a node:15.7.0-alpine3.10 container which is also using nginx:stable-alpine. Again, I've never faced this error before and I've committed zero new changes to my project. Why is this error occurring now and how do I fix it?
