Make externalDns + Fluent Bit optional

[rudolphjacksonm]

Some orgs may centrally provision these tools in their cluster, and then layer tooling charts on top. It would be good for these to be gated by an if clause so end-users can pick and choose whether they want this bundled in to the NXRM deployment.

[bobotimi]

Thank you @rudolphjacksonm for your comment. We are already working on making it optional and will make available soon.

[SamuelBagattin]

This chart is too much opinionated.
Most people want to install theses tools with their own lifecycle. ExternalDNS and FluentBit have nothing to do with Nexus.

[bobotimi]

@SamuelBagattin Here's a draft PR that shows how to make these optional - #46