Config

[applejag]

• pkg/config/doc.go
• pkg/config/config.go abstraction over viper
• Added example tests
• Added CHANGELOG.md. Collides with Added pkg/app/version.go and examples, changelog, and go.mod #2 but it's an easy merge.

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Related to #1, and based on iver-wharf/rfcs#4

[iverestefans]

I like it! Great job!

[fredx30]

Its clearly marked config which is good. Im not sure what the config is for though even after having skimmed though the source once.

[applejag]

Its clearly marked config which is good. Im not sure what the config is for though even after having skimmed though the source once.

Configuring Wharf. So for each component (wharf-provider-github, wharf-api, etc) they will use this library so they can be configured. Currently you can only configure Wharf via environment variables, which is very tedious once the configs options grow in numbers, which has started to happen in the wharf-api component.

Lettings users configure through files is just another means of configuring. They stack up and merge together, so if you define A=foo and B=bar in the config file and then set the A=moo in environment variables then the component will read the configs as solely A=moo and B=bar

When working in Kubernetes, it's often better to work with ConfigMaps than environment variables as it can support hot-reloading if the application itself supports it. This implementation does not support watching the config files for changes, but that's something we could add later.