Documentation
¶
Overview ¶
Package confkey looks for tags on a structure and set values based on the tag rather than the struct item names
Features ¶
Defaults are supported and can be fetched from the shell environment ¶
The tags can specify some formating like comma splits and other commonly seen patterns in config files.
Conversion of []string, ints, strings, time.Duration and booleans are support
Validations can be done on a struct basis using the github.com/choria-io/go-validators package
A sample structure might look like this, the package contains utilities to set values, apply defaults and perform validations
type Config struct {
Loglevel string `confkey:"loglevel" default:"warn" validate:"enum=debug,info,warn,error"`
Mode string `confkey:"mode" default:"server" validate:"enum=server,client"`
Servers []string `confkey:"servers" type:"comma_split" environment:"SERVERS"`
Path []string `confkey:"path" type:"path_split" default:"/bin:/usr/bin"`
I time.Duration `confkey:"interval" type:"duration" default:"1h"`
}
The utilities here will let you parse any config file that might have keys like loglevel etc and map the string values read from the text file onto the structure
Example (Basic) ¶
package main
import (
"fmt"
"os"
"strings"
confkey "github.com/choria-io/go-choria/confkey"
)
type Config struct {
Loglevel string `confkey:"loglevel" default:"warn" validate:"enum=debug,info,warn,error"`
Mode string `confkey:"mode" default:"server" validate:"enum=server,client"`
Servers []string `confkey:"servers" type:"comma_split" environment:"SERVERS"`
Path []string `confkey:"path" type:"colon_split" default:"/bin:/usr/bin"` // can also be path_split to be OS aware
}
func main() {
c := &Config{}
err := confkey.SetStructDefaults(c)
if err != nil {
panic(err)
}
fmt.Println("Defaults:")
fmt.Printf(" loglevel: %s\n", c.Loglevel)
fmt.Printf(" mode: %s\n", c.Mode)
fmt.Printf(" path: %s\n", strings.Join(c.Path, ","))
fmt.Println("")
// here you would read your config file, but lets just fake it
// and set specific values
// every call to SetStructFieldWithKey validates what gets set
err = confkey.SetStructFieldWithKey(c, "loglevel", "error")
if err != nil {
panic(err)
}
err = confkey.SetStructFieldWithKey(c, "mode", "client")
if err != nil {
panic(err)
}
// even though we are setting it, if the ENV is set it overrides
os.Setenv("SERVERS", "s1:1024, s2:1024")
err = confkey.SetStructFieldWithKey(c, "servers", "s:1024")
if err != nil {
panic(err)
}
fmt.Println("Loaded:")
fmt.Printf(" loglevel: %s\n", c.Loglevel)
fmt.Printf(" mode: %s\n", c.Mode)
fmt.Printf(" servers: %s\n", strings.Join(c.Servers, ","))
fmt.Println("")
// getting a string by name
fmt.Println("Retrieved:")
fmt.Printf(" loglevel: %s\n", confkey.StringFieldWithKey(c, "loglevel"))
fmt.Printf(" servers: %s\n", strings.Join(confkey.StringListWithKey(c, "servers"), ","))
fmt.Println("")
// but you can also validate the entire struct if you like, perhaps you
// set some stuff directly to its fields
err = confkey.Validate(c)
if err != nil {
fmt.Printf("invalid: %s\n", err)
panic(err)
}
fmt.Println("valid")
// setting a specific bad value yields an error
err = confkey.SetStructFieldWithKey(c, "loglevel", "fail")
if err != nil {
fmt.Printf("invalid: %s\n", err)
}
}
Output: Defaults: loglevel: warn mode: server path: /bin,/usr/bin Loaded: loglevel: error mode: client servers: s1:1024,s2:1024 Retrieved: loglevel: error servers: s1:1024,s2:1024 valid invalid: Loglevel enum validation failed: 'fail' is not in the allowed list: debug, info, warn, error
Index ¶
- Variables
- func BoolWithKey(target interface{}, key string) bool
- func DefaultString(target interface{}, key string) (string, bool)
- func Description(target interface{}, key string) (string, bool)
- func Environment(target interface{}, key string) (string, bool)
- func FieldWithKey(target interface{}, key string) (string, error)
- func FindFields(target interface{}, re string) ([]string, error)
- func Int64WithKey(target interface{}, key string) int64
- func IntWithKey(target interface{}, key string) int
- func IsDeprecated(target interface{}, key string) (bool, bool)
- func KeyTag(target interface{}, key string, tag string) (string, bool)
- func SetStructDefaults(target interface{}) error
- func SetStructFieldWithKey(target interface{}, key string, value interface{}) error
- func StringFieldWithKey(target interface{}, key string) string
- func StringListWithKey(target interface{}, key string) []string
- func Tag(s interface{}, field string, tag string) (string, bool)
- func Type(target interface{}, key string) (string, bool)
- func URL(target interface{}, key string) (string, bool)
- func Validate(target interface{}) error
- func Validation(target interface{}, key string) (string, bool)
- type Doc
- func (d *Doc) ConfigKey() string
- func (d *Doc) Default() string
- func (d *Doc) Deprecate() bool
- func (d *Doc) Description() string
- func (d *Doc) Environment() string
- func (d *Doc) SetDescription(desc string)
- func (d *Doc) StructKey() string
- func (d *Doc) Type() string
- func (d *Doc) URL() string
- func (d *Doc) Validation() string
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var Undocumented = "Undocumented"
Functions ¶
func BoolWithKey ¶
BoolWithKey retrieves a bool from target that matches key, false when not found
func DefaultString ¶
DefaultString retrieves the default for a field
func Description ¶
func Environment ¶
Environment retrieves the environment variable used to set a value
func FieldWithKey ¶
FieldWithKey determines the struct key name that is tagged with a certain confkey
func FindFields ¶
FindFields looks for fields matching regular expression re and return their keys
func Int64WithKey ¶
Int64WithKey retrieves an int from target that matches key, 0 when not found
func IntWithKey ¶
IntWithKey retrieves an int from target that matches key, 0 when not found
func IsDeprecated ¶
func SetStructDefaults ¶
func SetStructDefaults(target interface{}) error
SetStructDefaults extract defaults out of the tags and set them to the key
func SetStructFieldWithKey ¶
SetStructFieldWithKey finds the struct key that matches the confkey on target and assign the value to it
func StringFieldWithKey ¶
StringFieldWithKey retrieves a string from target that matches key, "" when not found
func StringListWithKey ¶
StringListWithKey retrieves a []string from target that matches key, empty when not found
func Validation ¶
Validation retrieves the validation configuration, empty when unvalidated
Types ¶
type Doc ¶
type Doc struct {
// contains filtered or unexported fields
}
func (*Doc) Description ¶
Description is a description of the item, empty when not set
func (*Doc) Environment ¶
Environment is an environment variable that can set this item, empty when not settable
func (*Doc) SetDescription ¶
SetDescription overrides the description of the key
Source Files