Environment Variables¶
Often, being able to override configuration with environment variables
is desirable. ResConfig
by default looks for environment
variables that map to configuration keys in a simple way, converting
“.”-delimited configuration keys to “_”-delimited, uppercase
environment variable names.
For example, the configuration key db.host
will be mapped to
DB_HOST
.
To avoid conflicts with variable names used for other purposes,
pprefix can be used. If you want MYAPP_
to be your prefix, supply
it as the envvar_prefix
option to ResConfig
:
config = ResConfig({"db.host": "localhost", "db.port": 5432},
envvar_prefix="MYAPP_")
Then, the MYAPP_DB_HOST
and MYAPP_DB_PORT
will map to db.host
and db.port
configuration keys.
Note
The escaped “.” in keys will map to a “_” character for environment variable names.