Replace base image to ubi

[jpkrohling]

The current CentOS base image seems to have some vulnerabilities, according to Quay:

https://quay.io/repository/jaegertracing/jaeger-operator/manifest/sha256:0f33e0ea725448c52f74cb47a27391749868c888ad4a1f3d553c7bc31a8a28a7?tab=vulnerabilities

Changing the base image to registry.access.redhat.com/ubi8/ubi seems to be a valid fix:

https://quay.io/repository/jpkroehling/jaeger-operator/manifest/sha256:e46a408f7496618b8923cf996dbad37d8b9c52b646eb0a97195ca01600f26226?tab=vulnerabilities

The ubi-minimal seems to be the default base image for new operators.

@pavolloffay: we started using the centos image because of the TLS cert generation as part of the ES provisioning. I think we talked about replacing that with regular Go code, instead of relying on openssl. Do you still want to do that? If so, this change here could come after your change, so that we use ubi-minimal, which lacks dnf. Otherwise, we could just use ubi instead.

[objectiser]

+1 , although can you use registry.redhat.io instead of registry.access.redhat.com.

[pavolloffay]

+1 on using ubi.

I would like to keep the scrip until ECL switches to golang based solution.

[jpkrohling]

I would like to keep the scrip until ECL switches to golang based solution.

Are they switching to golang at all?

[pavolloffay]

I don't think that will happen any time soon.

[amila-ku]

@jpkrohling would like to work on this. If it is agreed to use ubi will start to work on this.

[jpkrohling]

I think there's nothing preventing us from using ubi instead of centos, so, it's yours, @amila-ku!