Package envcfg provides functions to load values to a structure fields from .env file and from OS environment variables.
Declare a structure and use tag env to define associated environment variable names for desired fields.
type Cfg struct {
Debug bool `env:"DEBUG"`
DatabaseURL string `env:"DATABASE_URL"`
}
Create a new structure to provide default values.
cfg := Cfg{
Debug: true,
DatabaseURL: "sqlite:///db.sqlite",
}
Call envcfg.Load() to load values from environment variables.
err := envcfg.Load(&cfg)
Keep in mind that the values are first loaded from the .env file (if it exists) and then
from the OS environment variables that can override the values loaded from the file.
The syntax of the .env file should follow these rules:
- Each line should be in VAR=VAL format
- Lines beginning with # are processed as comments and ignored
- Blank lines are ignored
A limited number of field types are supported, but they should be enough for most cases.
Nested structures are supported, just mark nested fields with env tag as usual
(no special syntax for .env file required). To load .env file from a different location or
with a different name use envcfg.LoadFile().