[nginx] Add generated request id to headers

[foxylion]

To trace a request through all your services in ingress it would be good to add a Request-Id to request and response headers. This will allow tracking down all subsequent requests inside the cluster caused by one request from the outside.

We've already modified our nginx.tmpl but it would be great if this could be an (optional) default.

In case a default would be okay I can create a pull request (desired changes are here). For an optional default I would need some help to get the right place for adding the option to the ConfigMap. (I've never worked with Go yet.)

[aledbf]

@foxylion please check the custom-headers example

[aledbf]

@foxylion requested to add newrelic headers #180

[foxylion]

@aledbf Thank you, I didn't know that. But it will still leave the issue of setting also the response header (more_set_headers "Request-Id: $request_id";).

[aledbf]

@foxylion I saw this nginx/kubernetes-ingress#117 and the idea of the snippets is more than interesting. With that you can add the missing more_set_headers and also the HSTS configuration. WDYT?

[foxylion]

@aledbf Yes, this would solve this issue here completely.

But for the HSTS case (#314) the redirect configuration is still required and I'm unsure if this is not better something which should simply work more out of the box (the problem should be quite common on AWS).

[aledbf]

@foxylion right. Let me add the snippets first and then we see what is needed for the HSTS header

[foxylion]

@aledbf Ok, thanks. Then this one can be closed when nginx/kubernetes-ingress#117 is somehow merged. :)

[rchicoli]

This should be merged soon. Then you could freely add your own custom configmaps in different contexts like this:

metadata:
  annotations:
    nginx.org/location-snippets: |
       more_set_headers "Request-Id: $request_id";

Cheers.

[foxylion]

@aledbf This looks good, I'll give it a try when it is released.

In the case of "request id" it would be good to have such an option in the ConfigMap so that I do not have to modify all ingress configurations. May this be an option?