Prevent Nginx from caching nodejs responses

Question

I am using Nginx to proxy requests to server based on directory user want to access

server {
listen 80 default_server;
listen [::]:80 default_server ipv6only=on;


server_name localhost;

location / {

    proxy_pass http://****.***/;

}
location /app/{
    proxy_no_cache '1';
    proxy_cache_bypass  '1';

    proxy_buffering off;

    include proxy_params;
    proxy_pass http://localhost:3000/;

}
}

This is nginx configuration. A Node app is running on 3000 port Problem I am facing is

• Users access "/app"
• Server sends login.html from node app.
• User logins from the page.
• Node sends home.html after successful login.(Problem Lies here) Although Node is sending home.html but Nginx responds to request with 304 code and browser shows same login page again.

example of Node app

.....
app.get("/",function(req,res){
***Sends login page or home page based on session***
});
app.get("/processLogin",function(req,res){
***redirects to / after setting session****
});
.....

Answer 1

One question: do you use pm2 for your Node application ? Many use Nginx + pm2. For the development phase of pm2, you need to put the --watch flag while launching your App. pm2 load all the Node.js in memory and dont check file change on the hardisk. You have then a cache phenomenon.

So, during the development phase, in place of

pm2 start MyApp.js

do

pm2 start MyApp.js --watch

Honestly, I dont see how a browser cache or Nginx can cache variable responses given by node.js programs. It had to be the pm2, in my case.

Answer 2

Adding no-cache headers in nodejs helped to solve the problem.

Answer 3

In proxy mode nginx is using Expires header to reduce load on the backend server...

So simply set expires off; in the proxy location block and caching should be gone.

---

In case the caching occurs in the browser, you'll need to set the cache control header to no-cache:

add_header Cache-Control no-cache;