Environment variables

Code dealing with the environment variables resides in here where each attribute has an annotation which is the lowercase of the environment variable name.

At the moment the application is sourcing the following from the environment:

• OTEL_GRPC_ENDPOINT - needed if we want to use the otel grpc exporter for traces
• OTEL_HTTP_ENDPOINT - needed if we want to use the otel http exporter for traces (if grpc is specified this gets unused)
• TRACING_ENABLED - switch for tracing, defaults to enabled (true)
• LOG_LEVEL - log level, defaults to error
• LOG_FILE - log file which the log rotator will write into, make sure application user has permissions to write, defaults to log.txt
• PORT - http server port, defaults to 8000
• KRATOS_PUBLIC_URL - address of kratos apis
• HYDRA_ADMIN_URL - address of hydra admin apis