Upstream resolve breaks configuration

Question

I am on Ubuntu 16.04 with the latest NGINX installed from their official repository:

$ sudo nginx -v nginx version: nginx/1.11.8 

I have the following defined in /etc/nginx/sites-available/greendot.conf:

# local dnsmasq resolver 127.0.0.1; map $http_upgrade $connection_upgrade { default upgrade; '' close; } upstream websocket { zone elixr 64k; server greendot-elixr-1:4000 resolve; server greendot-elixr-2:4000 resolve; } server { listen 4000; location / { proxy_pass http://websocket; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection $connection_upgrade; } } 

I have followed the documentation on setting up DNS resolved upstream servers, and yet this configuration fails:

$ sudo nginx -T nginx: [emerg] invalid parameter "resolve" in /etc/nginx/sites-enabled/greendot-nginx.conf:11 nginx: configuration file /etc/nginx/nginx.conf test failed 

My goal is to simply create a server which uses DNS to periodically resolve its members. What am I doing wrong?

Answer 1

The resolve parameter is part of nginx's commercial offering.

Here's the approach I ended up using:

server { ... # Use docker's internal nameserver resolver 127.0.0.11 valid=10s ipv6=off; location / { set $target myproject-web; proxy_pass http://$target:8000; } } 

Note that:

• You have to define a variable (like $target), or nginx will query once, and use the resulting IP(s) forever (ignoring the resolver's 'valid' parameter).
• If the DNS query returns several IPs; nginx will round-robin to them.
• This approach may not work for you if you have more complex upstream requirements (backup endpoints, etc).