Yeah this does seem to be a bug, I am using the latest published chart version:

NAME           CHART VERSION	APP VERSION
grafana/loki   5.6.1        	2.8.2

if you look at the helpers.tpl link you posted you'll find the hardcoded line on L571:
client_max_body_size 4M;

and then below that on L597 is the user supplied config section:
{{- with .Values.gateway.nginxConfig.httpSnippet }}

So when one goes to try override with your own values in the nginxConfig section:

nginxConfig:
  httpSnippet: |-
    client_max_body_size 100M;
    proxy_read_timeout   600;
    proxy_send_timeout   600;

You get the nginx emerg error and new gateway pods will not startup:

nginx: [emerg] "client_max_body_size" directive is duplicate in /etc/nginx/nginx.conf:34

Are we missing something here Grafana team? @trevorwhitney

I guess, the client_max_body_size field must 1/ have its own value, or 2/ just remove it from the _helpers.tpl file to avoid duplication
Meanwhile waiting for the fix from Grafana, I made a workaround by adding a small change following the 1/ approach

In file values.yaml

gateway:
  nginxConfig:
    clientMaxBodySize: "10M"

In file _helpers.tpl

client_max_body_size {{ .Values.gateway.nginxConfig.clientMaxBodySize }};

@khanh96le nice workaround.
It's important to replace the hard coded values of the nginx config to variables so that we could override them from the values.yaml such as:
worker_processes, worker_rlimit_nofile, worker_connections, worker_connections,client_max_body_size , etc..

This sounds like a bug, thanks for bringing it up. I think the best thing to due here is to move the default client_max_body_size into the default for httpSnippet. I want to be careful not to promote every nginx config to a corresponding value in values.yaml, but I think it's reasonable to move a "block" of config into the httpSnippet section.

The outcome I'd like to see is, if I don't provide any custom values, I get the defaults of what the chart is now producing. If I want to override any value is this section, I have to provide the whole section. Sound good? If so, I'd be happy to review PR. If not, happy to hear your thoughts?

Thanks!

Hello, any news ?

This is a true bug ;)

Hi,
This bug is somewhat annoying, any update?

Thanks :)

Hello,

Would greatly appreciate if you can provide any update on this issue as it effect us as well.
Thank you

any progress with that? this is important issue

Hey, @trevorwhitney can you review my PR #12924?
I've implemented @khanh96le's approach as that seems reasonable, until there is a proper discussion about what should and should not be moved into the httpSnippet section.