Handling override of environment variables behavior is unexpected

[rsdmike]

When trying to override a value using environment variables, i.e:

export Service_Port=50001

Something a little strange seems to be happening. You can see the error that it can't convert a string to an int, but this is as it is trying to unmarshal into the configuration struct which of course port is an int. The funny thing is, that you can see that it takes effect, but not because it unmarsalled, but because it was successfully sent to consul first before unmarshalling to configuration, and then a little later it receives the configuration back from consul and gets the appropriate value.

TL;DR: It works, just not in the expected or preferred manner. Its unmarshalled into configuration coming back from Consul, not from reading env or toml directly/locally.

This issue doesn't present itself in config-seed though i do imagine it would present itself in the device-services-sdk.

Starting Configurable Application Service...
failed to initialize Registry: could not unmarshal configTree to configuration: (0, 0): Can't convert 50001(string) to int
Configuration loaded from registry with service key: AppService-rules-engine
level=INFO ts=2019-07-30T22:54:30.8862683Z app=AppService-rules-engine source=sdk.go:250 msg="Configuration and logger successfully initialized"
level=INFO ts=2019-07-30T22:54:30.8972703Z app=AppService-rules-engine source=main.go:43 msg="Loading Configurable Pipeline..."
level=INFO ts=2019-07-30T22:54:30.8972703Z app=AppService-rules-engine source=sdk.go:374 msg="Listening for changes from registry"
level=INFO ts=2019-07-30T22:54:30.9062645Z app=AppService-rules-engine source=server.go:74 msg="Registering standard routes..."
level=INFO ts=2019-07-30T22:54:30.9182679Z app=AppService-rules-engine source=sdk.go:398 msg="Writable configuration has been updated from Registry"
level=INFO ts=2019-07-30T22:54:30.9222626Z app=AppService-rules-engine source=sdk.go:199 msg="MessageBus trigger selected"
level=INFO ts=2019-07-30T22:54:30.9302673Z app=AppService-rules-engine source=sdk.go:417 msg="ReLoaded Configurable Pipeline from Registry"
level=INFO ts=2019-07-30T22:54:30.9362657Z app=AppService-rules-engine source=messaging.go:45 msg="Initializing Message Bus Trigger. Subscribing to topic: events on port 5563 , Publish Topic:  on port 5566"
level=INFO ts=2019-07-30T22:54:30.957264Z app=AppService-rules-engine source=sdk.go:100 msg="AppServiceConfigurable-rules-engine has Started"
level=INFO ts=2019-07-30T22:54:30.9642924Z app=AppService-rules-engine source=server.go:96 msg="Starting HTTP Server on port :50001

[lenny-goodell]

addressed by #325