nginx reverse proxy websockets

Question

nginx now supports proxying websockets, but I was unable to find any information on how to do this without having a separate location block that applies to URIs on whic

Answer 1

Why doesn't nginx just forward the original Upgrade/Connection headers?

From the official documentation: since the “Upgrade” is a hop-by-hop header, it is not passed from a client to proxied server

See RFC 2616.

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I don't want the Upgrade header or Connection being set to "upgrade" unless that's what the browser sent,

There is also an example:

map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}

server {
    ...

    location /chat/ {
        proxy_pass http://backend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
    }
}

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Connection is 'upgrade' for non-websocket requests, which is also bad.

Do you actually know what the Connection header means? Just a quote from RFC: for each connection-token in this field, remove any header field(s) from the message with the same name as the connection-token.

How it can be bad?