configure is a golang library that populates a struct from environment variables, command line arguments and YAML files.
It works by reading a struct definition with special tags.
The latest can be seen if you run:
godoc github.com/gravitational/configure
But here's a quickstart: Define a sample structure, for example:
type Config struct {
StringVar string `env:"STRING_VAR" cli:"string-var" yaml:"string_var"`
BoolVar bool `env:"BOOL_VAR" cli:"bool_var" yaml:"bool_var"`
IntVar int `env:"INT_VAR" cli:"int_var" yaml:"int_var"`
HexVar hexType `env:"HEX_VAR" cli:"hex_var" yaml:"hex_var"`
MapVar map[string]string `env:"MAP_VAR" cli:"map_var" yaml:"map_var,flow"`
SliceMapVar []map[string]string `env:"SLICE_MAP_VAR" cli:"slice_var" yaml:"slice_var,flow"`
}Then you can query the environment and populate that structure from environment variables, YAML files or command line arguments.
import (
"os"
"github.com/gravitational/configure"
)
func main() {
var cfg Config
// parse environment variables
err := configure.ParseEnv(&cfg)
// parse YAML
err = configure.ParseYAML(&cfg)
// parse command line arguments
err = configure.ParseCommandLine(&cfg, os.Args[1:])
}