revip

package module
v0.0.1 Latest Latest
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 Go to latest Published: Dec 10, 2022 License: Unlicense Imports: 16 Imported by: 1

README

revip

Dead-simple configuration loader.

It supports:

  • JSON, TOML, YAML and you could add your own format unmarshaler (see Unmarshaler type)
  • file, reader and environment sources support, also you could add your own (see Option type and sources.go)
  • extendable postprocessing support (defaults, validation, expansion, see Option type and postprocess.go)
  • dot-notation to access configuration keys

Godoc

example
run

Basic example showing basics about configuration loading:

  • default values
  • validation rules
  • config expansion (loading key from file)
  • working with nested types
  • unmarshaling from JSON, YAML, TOML
$ cd ./example/basic
$ go run ./main.go
(main.Config) {
 SerialNumber: (int) 1,
 Nested: (*main.NestedConfig)(0xc00000e0c0)({
  Value: (string) (len=11) "hello world",
  Flag: (bool) false
 }),
 MapNested: (map[string]*main.NestedConfig) {
 },
 SliceNested: ([]*main.NestedConfig) {
 },
 StringSlice: ([]string) <nil>,
 IntSlice: ([]int) (len=3 cap=3) {
  (int) 666,
  (int) 777,
  (int) 888
 },
 key: (string) (len=18) "super secret value"
}

Run basic example with some keys befined through environment variables:

environment variables are defined in makefile

$ make
(main.Config) {
 SerialNumber: (int) 2,
 Nested: (*main.NestedConfig)(0xc00000e0c0)({
  Value: (string) (len=12) "\"hello user\"",
  Flag: (bool) false
 }),
 MapNested: (map[string]*main.NestedConfig) {
 },
 SliceNested: ([]*main.NestedConfig) {
 },
 StringSlice: ([]string) <nil>,
 IntSlice: ([]int) (len=3 cap=3) {
  (int) 888,
  (int) 777,
  (int) 666
 },
 key: (string) (len=18) "super secret value"
}

license

public domain

Documentation

Index

Constants

View Source 
const (
	SchemeEmpty   = ""
	SchemeFile    = "file" // file://./config.yml
	SchemeEnviron = "env"  // env://prefix
)

Variables

View Source 
var (
	// FromSchemes represents schemes supported for sources.
	FromSchemes = []string{
		SchemeFile,
		SchemeEnviron,
	}
	// ToSchemes represents schemes supported for destrinations.
	ToSchemes = []string{
		SchemeFile,
	}
)

Functions

func Postprocess 

func Postprocess(c Config, options ...PostprocessOption) error

func TreePathString 

func TreePathString(t Tree) string

Types

type Config 

type Config interface{}

Config is a configuration represented by user-specified type.

type Container 

type Container struct {
	// contains filtered or unexported fields
}

Container represents configuration loaded by `Load`.

func Load 

func Load(v Config, options ...SourceOption) (*Container, error)

Load applies each `options` in order to fill the configuration in `v` and constructs a `*Revip` data-structure.

func New 

func New(c Config) *Container

New wraps configuration represented by `c` with come useful methods.

func (*Container) Clone 

func (r *Container) Clone() (Config, error)

Clone returns a shallow copy of the configuration with the same type.

func (*Container) Copy 

func (r *Container) Copy(v Config) error

Copy writes a shallow copy of the configuration into `v`.

func (*Container) DeepClone 

func (r *Container) DeepClone() (Config, error)

DeepClone returns a deep copy of the configuration with the same type.

func (*Container) DeepCopy 

func (r *Container) DeepCopy(v Config) error

DeepCopy writes a deep copy of the configuration into `v`.

func (*Container) Default 

func (r *Container) Default() error

Default postprocess configuration with default values or returns an error.

func (*Container) Empty 

func (r *Container) Empty()

Empty allocates a new empty configuration, discarding any previously loaded data.

func (*Container) EmptyClone 

func (r *Container) EmptyClone() Config

EmptyClone returns empty configuration type clone.

func (*Container) Expand 

func (r *Container) Expand() error

Expand postprocess configuration with expansion or returns an error.

func (*Container) Path 

func (r *Container) Path(path string) (Config, error)

Path uses dot notation to retrieve substruct addressable by `path` or return an error if key was not found(`ErrNotFound`) or something gone terribly wrong.

func (*Container) Replace 

func (r *Container) Replace(c Config)

Replace overrides internally stored configuration with passed value.

func (*Container) Unwrap 

func (r *Container) Unwrap() Config

Unwrap returns a pointer to the inner configuration data structure.

func (*Container) Validate 

func (r *Container) Validate() error

Validate postprocess configuration with validation or returns an error.

type Defaultable 

type Defaultable interface {
	Default()
}

Defaultable is an interface which any `Config` could implement to define a custom default values for sub-tree it owns.

type DestinationOption 

type DestinationOption func(c Config) error

func ToFile 

func ToFile(path string, f Marshaler) DestinationOption

ToFile is an `DestinationOption` constructor which creates a thunk to write configuration to file addressable by `path` with content encoded with `f` marshaler.

func ToURL 

func ToURL(u string, e Marshaler) (DestinationOption, error)

ToURL creates a destination from URL. Example URL's:

  • file://./config.yml

func ToWriter 

func ToWriter(w io.Writer, f Marshaler) DestinationOption

ToWriter is an `DestinationOption` constructor which creates a thunk to write configuration to `r` and encode it with `f` marshaler.

type ErrFileNotFound 

type ErrFileNotFound struct {
	Path string
	Err  error
}

ErrFileNotFound should be returned if configuration file was not found.

func (*ErrFileNotFound) Error 

func (e *ErrFileNotFound) Error() string

type ErrMarshal 

type ErrMarshal struct {
	At  string
	Err error
}

ErrMarshal should be returned if key marshaling failed.

func (*ErrMarshal) Error 

func (e *ErrMarshal) Error() string

type ErrPathNotFound 

type ErrPathNotFound struct {
	Path string
}

ErrPathNotFound should be returned if key (path) was not found in configuration.

func (*ErrPathNotFound) Error 

func (e *ErrPathNotFound) Error() string

type ErrPostprocess 

type ErrPostprocess struct {
	Path string
	Err  error
}

ErrPostprocess represents an error occured at the postprocess stage (set defaults, validation, etc)

func (*ErrPostprocess) Error 

func (e *ErrPostprocess) Error() string

type ErrUnexpectedKind 

type ErrUnexpectedKind struct {
	Type     reflect.Type
	Got      reflect.Kind
	Expected []reflect.Kind
}

ErrUnexpectedKind represents an unexpected interface{} value kind received by some function. For example passing non pointer value to a function which expects pointer (like json.Unmarshal)

func (*ErrUnexpectedKind) Error 

func (e *ErrUnexpectedKind) Error() string

type ErrUnexpectedScheme 

type ErrUnexpectedScheme struct {
	Got      string
	Expected []string
}

ErrUnexpectedScheme represents an unexpected URL scheme.

func (*ErrUnexpectedScheme) Error 

func (e *ErrUnexpectedScheme) Error() string

type ErrUnmarshal 

type ErrUnmarshal struct {
	At  string
	Err error
}

ErrUnmarshal should be returned if key unmarshaling failed.

func (*ErrUnmarshal) Error 

func (e *ErrUnmarshal) Error() string

type Expandable 

type Expandable interface {
	Expand() error
}

Expandable is an interface which any `Config` could implement to define an expansion rules for sub-tree it owns.

type Marshaler 

type Marshaler = func(v interface{}) ([]byte, error)

Marshaler describes a generic marshal interface for data encoding which could be used to extend supported formats by defining new `Option` implementations. 

var (
	JsonMarshaler Marshaler = json.Marshal
	YamlMarshaler Marshaler = yaml.Marshal
	TomlMarshaler Marshaler = toml.Marshal
)

type PostprocessOption 

type PostprocessOption func(c Tree) error

func WithDefaults 

func WithDefaults() PostprocessOption

func WithExpansion 

func WithExpansion() PostprocessOption

func WithNoNilPointers 

func WithNoNilPointers() PostprocessOption

func WithValidation 

func WithValidation() PostprocessOption

type SourceOption 

type SourceOption func(c Config) error

func FromEnviron 

func FromEnviron(prefix string) SourceOption

FromEnviron is an `SourceOption` constructor which creates a thunk to read configuration from environment. It uses `github.com/kelseyhightower/envconfig` underneath.

func FromFile 

func FromFile(path string, f Unmarshaler) SourceOption

FromFile is an `SourceOption` constructor which creates a thunk to read configuration from file addressable by `path` with content decoded with `f` unmarshaler.

func FromReader 

func FromReader(r io.Reader, f Unmarshaler) SourceOption

FromReader is an `SourceOption` constructor which creates a thunk to read configuration from `r` and decode it with `f` unmarshaler. Current implementation buffers all data in memory.

func FromURL 

func FromURL(u string, d Unmarshaler) (SourceOption, error)

FromURL creates a source from URL. Example URL's:

  • file://./config.yml
  • env://prefix

type Tree 

type Tree interface {
	Interface() interface{}
	Value() reflect.Value
	WithValue(reflect.Value) Tree
	Next() []Tree
	WithNext(Tree) Tree
	Previous() Tree
	WithPrevious(Tree) Tree
	Name() string
}

func NewTree 

func NewTree(value reflect.Value, handler func(Tree) error) (Tree, error)

func TreePathSlice 

func TreePathSlice(t Tree) []Tree

type TreeArrayFieldNode 

type TreeArrayFieldNode struct {
	Tree
	Field int
}

func (*TreeArrayFieldNode) Name 

func (n *TreeArrayFieldNode) Name() string

type TreeMapFieldNode 

type TreeMapFieldNode struct {
	Tree
	Field reflect.Value
}

func (*TreeMapFieldNode) Name 

func (n *TreeMapFieldNode) Name() string

type TreeNode 

type TreeNode struct {
	Val    reflect.Value
	Childs []Tree
	Parent Tree
}

func (*TreeNode) Interface 

func (n *TreeNode) Interface() interface{}

func (*TreeNode) Name 

func (n *TreeNode) Name() string

func (*TreeNode) Next 

func (n *TreeNode) Next() []Tree

func (*TreeNode) Previous 

func (n *TreeNode) Previous() Tree

func (*TreeNode) Value 

func (n *TreeNode) Value() reflect.Value

func (*TreeNode) WithNext 

func (n *TreeNode) WithNext(t Tree) Tree

func (*TreeNode) WithPrevious 

func (n *TreeNode) WithPrevious(t Tree) Tree

func (*TreeNode) WithValue 

func (n *TreeNode) WithValue(v reflect.Value) Tree

type TreeSliceFieldNode 

type TreeSliceFieldNode struct {
	Tree
	Field int
}

func (*TreeSliceFieldNode) Name 

func (n *TreeSliceFieldNode) Name() string

type TreeStructFieldNode 

type TreeStructFieldNode struct {
	Tree
	Field reflect.StructField
}

func (*TreeStructFieldNode) Name 

func (n *TreeStructFieldNode) Name() string

type Unmarshaler 

type Unmarshaler = func(in []byte, v interface{}) error

Unmarshaler describes a generic unmarshal interface for data decoding which could be used to extend supported formats by defining new `SourceOption` implementations. 

var (
	JsonUnmarshaler Unmarshaler = json.Unmarshal
	YamlUnmarshaler Unmarshaler = yaml.Unmarshal
	TomlUnmarshaler Unmarshaler = toml.Unmarshal
)

type Validatable 

type Validatable interface {
	Validate() error
}

Validatable is an interface which any `Config` could implement to define a validation rules for sub-tree it owns.

Source Files

View all Source files

Directories

Path Synopsis
example
basic

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