add requestHeaderModifier fail

[Eason-Liu]

Describe the bug
I have configured httproute.spec.rules.filters.requestHeaderModifier.add.name and httproute.spec.rules.filters.requestHeaderModifier.add.value in httproute. The values are X-Real-IP and remote_addr, respectively. httproute.spec.rules.filters.type is RequestHeaderModifier. However, in the nginx-gateway Pod, remote_addr is recognized as proxy_set_header X-Real-IP "${x_real_ip_header_var}remote_addr"; how can I configure it to recognize as proxy_set_header X-Real-IP "$remote_addr"? I have tried configuring httproute.spec.rules.filters.requestHeaderModifier.add.value as $remote_addr, but it causes all proxy_set_header commands in the nginx-gateway to not be recognized. How can I resolve this issue?

[kate-osborn]

Hi @Eason-Liu, we don't support setting nginx variables like $remote_addr in requestHeaderModifier filter, or any of the HeaderModifiers.

If you describe the HTTPRoute where you defined this requestHeaderModifier you should see an error like:

All rules are invalid: spec.rules[0].filters[0].RequestHeaderModifier.add: Invalid value: v1.HTTPHeader{Name:"X-Real-IP", Value:"$remote_addr"}: a valid value must have all '"' escaped and must not contain any '$' or end with an unescaped '\' (e.g. 'my-header-value',  or 'example/12345==', regex used for validation is '([^"$\\]|\\[^$])*')

Can I ask what you are trying to achieve? Are you trying to preserve the client's IP address? Would this planned feature help: #1406?

[Eason-Liu]

Yes, I want to retain the client's real IP address for log analysis.

[kate-osborn]

Yes, I want to retain the client's real IP address for log analysis.

@Eason-Liu thanks for the response. #1406 will add this feature and is planned for the next release.