notary server: support vectors/lists of strings from environment variables as config properties

[kubkon]

Extracted from #817 and more specifically from comment #817 (comment)

Once #817 we will want to support parsing vector/list of strings from env variables when populating server's config properties.

[sinui0]

@kubkon is this something that your team has an actual need for? My inclination is to not support this feature

[kubkon]

@kubkon is this something that your team has an actual need for? My inclination is to not support this feature

It would be useful for rolling out the notary server using env vars without the need to resorting to a config file. We do that for our zk provers in ansible too. Anyhow, please note that this issue was first brought up by @yuroitaki and I just provided a fix after landing JWT support.

[kubkon]

@sinui0 here's the original comment mentioning the need for this #817 (comment)

[sinui0]

My recommendation would be to use the file configuration and not rely on env variables. AFAIK its not a common practice to do such extensive configuration via env vars.

Thanks for the reference, I'm going to veto this suggestion from @yuroitaki though

Part of my conservative stance here is related to a higher-level conversation we need to have about the scope of our reference implementation and its maintenance long term. If you need this feature right now I would suggest using it in your own fork