Otdfbt

The upstream server is sending a 404 with a header of Cache-Control: no-cache.

Due to this, nginx is not caching the request. How can I force it to cache the request?

This caching is only required on the upstream repsponses with a 404 status code.

It can keep the original header and pass this on to the client, but I don't want it sending a 'fresh' request to the page.

I also don't want to remove the header entirely as some of the requests would have a appropriate 'cache control' header set to expire in for example 24h. Hence I can't use proxy_ignore_headers.

I've been lucky in that I can do this based on the response code (404) and by intercepting the error:

#user www-data;
#worker_processes 4;
#pid /run/nginx.pid;
#
#events 
# worker_connections 768;
# # multi_accept on;
#
user www-data;
worker_processes 4;

error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;


events 
 worker_connections 1024;



http 
 include /etc/nginx/mime.types;
 default_type application/octet-stream;

 log_format main '$remote_addr - $remote_user [$time_local] "$request" '
 '$status $body_bytes_sent "$http_referer" '
 '"$http_user_agent" "$http_x_forwarded_for"';

 access_log /var/log/nginx/access.log main;
 #access_log /dev/null;
 #error_log /dev/null;

 sendfile off;
 #tcp_nopush on;

 keepalive_timeout 65;

 #gzip on;
 proxy_cache_path /tmp/nginx levels=1:2 keys_zone=STATIC:10m inactive=24h max_size=1g;

 server 
 listen 80 default_server;
 listen [::]:80 default_server;
 server_name _;
 return 301 https://$host$request_uri;
 

 server 
 listen 443 default_server ssl;
 listen [::]:443 default_server ssl;

 server_name localhost;

 ssl on;
 ssl_certificate /opt/bitnami/nginxssl/nginxssl.crt;
 ssl_certificate_key /opt/bitnami/nginxssl/selfbuild.key;
 recursive_error_pages on;

 location / 
 proxy_pass https://localhost:9443/;
 proxy_set_header Host $host;
 proxy_set_header X-Forwarded-Proto $scheme;
 proxy_set_header X-Real-IP $remote_addr;
 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

 proxy_cache STATIC;
 # Let the Set-Cookie header through.

 add_header X-Proxy-Cache $upstream_cache_status;
 proxy_cache_valid 404 60m;
 error_page 404 /404.html;
 proxy_intercept_errors on;

 

 location /404.html 

 proxy_pass https://localhost:9443/404.html;

 proxy_hide_header Set-Cookie;
 proxy_hide_header Cache-Control;
 proxy_hide_header Expires;
 proxy_hide_header Pragma;
 proxy_hide_header X-Accel-Expires;
 proxy_ignore_headers "Set-Cookie" "Cache-Control" "Expires" "X-Accel-Expires";

 proxy_set_header Host $host;
 proxy_set_header X-Forwarded-Proto $scheme;
 proxy_set_header X-Real-IP $remote_addr;
 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

 proxy_cache STATIC;

 add_header X-Proxy-Cache $upstream_cache_status;
 proxy_cache_valid 404 60m;