1. Proposed title of this feature request
Add the option to reference certificates from a secret in an edge terminated secured route

2. What is the nature and description of the request?
Edge terminated secured routes that are assigned a specific certificate include the public and private parts of the certificate as part of the route yaml definition. This is a problem when using GITOPS because the yaml definition file is pushed to a git repo and no sensitive information should be added there.
At the moment the possible workaround customers can apply is using ingress objects instead of routes, because ingress reference the TLS certificate via a secret.
What I would like to see is an additional field in the route spec like the valueFrom existing in the pod spec:

$ oc explain pod.spec.containers.env
...
FIELDS:
name <string> required
Name of the environment variable. Must be a C_IDENTIFIER.

value <string>
Variable references $(VAR_NAME) are expanded using the previous defined
environment variables in the container and any service environment
variables. If a variable cannot be resolved, the reference in the input
string will be unchanged. The $(VAR_NAME) syntax can be escaped with a
double $$, ie: $$(VAR_NAME). Escaped references will never be expanded,
regardless of whether the variable exists or not. Defaults to "".

valueFrom <Object>
Source for the environment variable's value. Cannot be used if value is not
empty.

3. Why does the customer need this? (List the business requirements here)
We are recommending and encouraging our customers to use gitops and we should close the security risks it has.

4. List any affected packages or components.