nginx – How to Make Nginx Always Return HTTP 503

503-errorhaproxynginx

I am using HAproxy in front of an app that is on multiple other servers. I would like to set up a vhost in a local nginx instance that only serves a 503 for every request (to use as the 'backup' server when all backends are down). I know how to set the custom error page (as in How can I make Nginx return HTTP 503 when my proxied app server is down?) but how I can make it so that every request to nginx returns a 503?

Best Answer

This doesn't work?

location / {
  return 503;
}

There might be some tricks you have to use to get assets to show up on your custom error page (i.e., say your 503.html has an image in it. You have to do some logic to make the image show up with a 200 code, otherwise it'll be missing with a 503).

Correct way in new versions of nginx

Turn out my first answer to this question was correct at certain time, but it turned into another pitfall - to stay up to date please check Taxing rewrite pitfalls

I have been corrected by many SE users, so the credit goes to them, but more importantly, here is the correct code:

server {
       listen         80;
       server_name    my.domain.com;
       return         301 https://$server_name$request_uri;
}

server {
       listen         443 ssl;
       server_name    my.domain.com;
       # add Strict-Transport-Security to prevent man in the middle attacks
       add_header Strict-Transport-Security "max-age=31536000" always; 

       [....]
}

Nginx – How to make nginx reverse proxy let 503 error pages pass through to client

Turns out there was truly an error while serving the 503 page so nginx was forwarding the response correctly afterall.

However, the relevant nginx setting is proxy_intercept_errors off; which is already the default..

Best Answer

Related Solutions

NGINX Redirect – How to Rewrite All HTTP Requests to HTTPS While Maintaining Sub-Domain

Correct way in new versions of nginx

Nginx – How to make nginx reverse proxy let 503 error pages pass through to client

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