1. Proposed title of this feature request

Add ability to pass in environment variables to external-dns pod

2. What is the nature and description of the request?

We need to leverage features of external-dns not exposed by the External DNS Operator. We would like the ability to pass in environment variables to the DNS pod so we can leverage the following features of external-dns

• Event based updating  -events (event based sync instead of intervals)
• Setting max results value -infoblox-max-results (default is 1000 which we have hit and we need to set it to > 3500)
• Setting --no-infoblox-ssl-verify to use a reverse proxy 

Those are a must, but we also utilize the following options.

--log-level=info

--log-format=text

--interval

--registry

3. Why does the customer need this? (List the business requirements here)

Customer can't adopt EDO without these changes due to configuration of Infoblox in their environment.