Ingress route - path based routing to different React app
You could use openshift routes instead of ingress for that, you can check on the docs how to apply it https://docs.openshift.com/container-platform/3.11/architecture/networking/routes.html#path-based-routes
One detail to pay attention if that your app will receive the relative path, it is not strip out of your request, for instance:
apps.mydomain.com/app2/api ---> app-2-api.svc:8080/app2/api
I don't think this is possible to solve using Openshift Router (see this issue).
With Nginx Ingress it could be easily accomplished using annotation nginx.ingress.kubernetes.io/rewrite-target: /