On configured AKS there is docker container with application that is using AAD authentication.
Based on this article there is also configured ingress. API is working
You have to make a decision whether to use HTTPS or not. If this is just the start of a development cycle, start without it and get auth to work - but implement HTTPS as soon as possible.
AAD supports both http and https, but of course, the reply urls must be added to the application registration respectively.
As @mihail-stancescu says, ssl-redirect must be set to false, if you choose not to use HTTPS. In addition to this, you also have to ensure that your app does not make the redirect from HTTP to HTTPS.
Using curl with -L -k and -v options will give you a lot of information on what is actually happening with your requests.
When the http/https thing is solved, you have to remove any rewrite annotations you have in your ingress. (e.g. ingress.kubernetes.io/rewrite-target: /
should be removed).
Now, if your ingress path to the service in question is e.g. /myservice, then the reply-url should also have that part of the path added ([host]/myservice/signin-oidc) - both in the AAD application registration and in the configuration of your app. (The path in the config should not contain the host)
If you are using https, then you must also have a proper certificate. You can use the free LetsEncrypt (https://letsencrypt.org/) in conjunction with KubeLego (https://github.com/jetstack/kube-lego), where you can find some nice examples on how to implement it.
Have you tried this?
By default the controller redirects HTTP clients to the HTTPS port 443 using a 308 Permanent Redirect response if TLS is enabled for that Ingress.
This can be disabled globally using
ssl-redirect: "false"
in the NGINX config map, or per-Ingress with thenginx.ingress.kubernetes.io/ssl-redirect: "false"
annotation in the particular resource.
More information on this on the Ingress documentation link.