README
¶
Description
Package rconfig implements a CLI configuration reader with struct-embedded defaults, environment variables and posix compatible flag parsing using the pflag library.
Installation
Install by running:
go get -u github.com/Luzifer/rconfig
Run tests by running:
go test -v -race -cover github.com/Luzifer/rconfig
Usage
As a first step define a struct holding your configuration:
type config struct {
Username string `default:"unknown" flag:"user" description:"Your name"`
Details struct {
Age int `default:"25" flag:"age" env:"age" description:"Your age"`
}
}
Next create an instance of that struct and let rconfig fill that config:
var cfg config
func init() {
cfg = config{}
rconfig.Parse(&cfg)
}
You're ready to access your configuration:
func main() {
fmt.Printf("Hello %s, happy birthday for your %dth birthday.",
cfg.Username,
cfg.Details.Age)
}
More info
You can see the full reference documentation of the rconfig package at godoc.org, or through go's standard documentation system by running godoc -http=:6060 and browsing to http://localhost:6060/pkg/github.com/Luzifer/rconfig after installation.
Documentation
¶
Overview ¶
Package rconfig implements a CLI configuration reader with struct-embedded defaults, environment variables and posix compatible flag parsing using the pflag library.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Parse ¶
func Parse(config interface{}) error
Parse takes the pointer to a struct filled with variables which should be read from ENV, default or flag. The precedence in this is flag > ENV > default. So if a flag is specified on the CLI it will overwrite the ENV and otherwise ENV overwrites the default specified.
For your configuration struct you can use the following struct-tags to control the behavior of rconfig:
default: Set a default value env: Read the value from this environment variable flag: Flag to read in format "long,short" (for example "listen,l") description: A help text for Usage output to guide your users
The format you need to specify those values you can see in the example to this function.
Example ¶
// We're building an example configuration with a sub-struct to be filled
// by the Parse command.
config := struct {
Username string `default:"unknown" flag:"user,u" description:"Your name"`
Details struct {
Age int `default:"25" flag:"age" description:"Your age"`
}
}{}
// To have more relieable results we're setting os.Args to a known value.
// In real-life use cases you wouldn't do this but parse the original
// commandline arguments.
os.Args = []string{
"example",
"--user=Luzifer",
}
Parse(&config)
fmt.Printf("Hello %s, happy birthday for your %dth birthday.",
config.Username,
config.Details.Age)
// You can also show an usage message for your user
Usage()
Output: Hello Luzifer, happy birthday for your 25th birthday.
Types ¶
This section is empty.
Source Files