nginx-ingress config map snippets being ignored by the nginx.conf

If you'd like to modify your Kubernetes Ingress the annotation options are these:

• nginx.ingress.kubernetes.io/configuration-snippet for an nginx location block snippet
• nginx.ingress.kubernetes.io/server-snippet for a snippet in the nginx config service block

Looks like you are using nginx.org/location-snippets: for that case.

There's also a YAML invalid syntax on nginx config example and also you should use plurals as in server-snippets according to this example. There's a typo in the docs as of this writing. Opened this ticket to follow up.

It should be something like this:

  server-snippets: |    location /messagehub {      proxy_set_header Upgrade $http_upgrade;      proxy_http_version 1.1;      proxy_set_header X-Forwarded-Host $http_host;      proxy_set_header X-Forwarded-Proto $scheme;      proxy_set_header X-Forwarded-For $remote_addr;      proxy_set_header Host $host;      proxy_set_header Connection "upgrade";      proxy_cache_bypass $http_upgrade;      }

instead of this:

  server-snippet: |    location /messagehub {      proxy_set_header Upgrade $http_upgrade;      proxy_http_version 1.1;      proxy_set_header X-Forwarded-Host $http_host;      proxy_set_header X-Forwarded-Proto $scheme;      proxy_set_header X-Forwarded-For $remote_addr;      proxy_set_header Host $host;      proxy_set_header Connection "upgrade";      proxy_cache_bypass $http_upgrade;    }

Notice the indentation of the last curly brace.

It turns out that my problem was due to the content of the snippet that I was applying. Every time you run kubectl apply -f myconfigmap.yaml, a validation is run against the changes that you are trying to apply to the nginx.conf. When this validation fails, it fails silently and there is nothing to alert you to this in the terminal.

In fact, you still get the configmap/nginx-ingress-controller configured message.

For example, when I add this to the config map, it updates the nginx.conf as expected:

http-snippet: |  sendfile on;

However, when I add this, nothing changes:

http-snippet: |  sendfile on;  tcp_nopush on;

The reason being that this has failed validation, but the only way to find that out is to look at the logs of the nginx ingress controller pod. In this instance I see:

Error: exit status 12018/10/16 07:45:49 [emerg] 470#470: "tcp_nopush" directive is duplicate in /tmp/nginx-cfg468835321:245nginx: [emerg] "tcp_nopush" directive is duplicate in /tmp/nginx-cfg468835321:245nginx: configuration file /tmp/nginx-cfg468835321 test failed

So I was duplicating a directive that already existed.

I spent a day untill got that for ingress-nginx (from Kubernetes) there are *-snippet, but for nginx-ingress (from NGINX) that *-snippets with s.

Look here:

• ingress-nginx: https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/configmap/#main-snippet
• nginx-ingress: https://docs.nginx.com/nginx-ingress-controller/configuration/global-configuration/configmap-resource/#snippets-and-custom-templates