first commit

provider/arg/provider.go

@@ -0,0 +1,136 @@
+package arg
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"strings"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/key"
+	"gitoa.ru/go-4devs/config/value"
+	"gopkg.in/yaml.v3"
+)
+
+var _ config.Provider = (*Provider)(nil)
+
+type Option func(*Provider)
+
+func WithKeyFactory(factory config.KeyFactory) Option {
+	return func(p *Provider) { p.key = factory }
+}
+
+func New(opts ...Option) *Provider {
+	p := Provider{
+		key: key.Name,
+	}
+
+	for _, opt := range opts {
+		opt(&p)
+	}
+
+	return &p
+}
+
+type Provider struct {
+	args map[string][]string
+	key  config.KeyFactory
+}
+
+// nolint: cyclop
+func (p *Provider) parseOne(arg string) (name, val string, err error) {
+	if arg[0] != '-' {
+		return
+	}
+
+	numMinuses := 1
+
+	if arg[1] == '-' {
+		numMinuses++
+	}
+
+	name = strings.TrimSpace(arg[numMinuses:])
+	if len(name) == 0 {
+		return
+	}
+
+	if name[0] == '-' || name[0] == '=' {
+		return "", "", fmt.Errorf("%w: bad flag syntax: %s", config.ErrInvalidValue, arg)
+	}
+
+	for i := 1; i < len(name); i++ {
+		if name[i] == '=' || name[i] == ' ' {
+			val = strings.TrimSpace(name[i+1:])
+			name = name[0:i]
+
+			break
+		}
+	}
+
+	if val == "" && numMinuses == 1 && len(arg) > 2 {
+		name, val = name[:1], name[1:]
+	}
+
+	return name, val, nil
+}
+
+func (p *Provider) parse() error {
+	if len(p.args) > 0 {
+		return nil
+	}
+
+	p.args = make(map[string][]string, len(os.Args[1:]))
+
+	for _, arg := range os.Args[1:] {
+		name, value, err := p.parseOne(arg)
+		if err != nil {
+			return err
+		}
+
+		if name != "" {
+			p.args[name] = append(p.args[name], value)
+		}
+	}
+
+	return nil
+}
+
+func (p *Provider) Name() string {
+	return "arg"
+}
+
+func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
+	return p.key(ctx, key) != ""
+}
+
+func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+	if err := p.parse(); err != nil {
+		return config.Variable{Provider: p.Name()}, err
+	}
+
+	k := p.key(ctx, key)
+	if val, ok := p.args[k]; ok {
+		switch {
+		case len(val) == 1:
+			return config.Variable{
+				Name:     k,
+				Provider: p.Name(),
+				Value:    value.JString(val[0]),
+			}, nil
+		default:
+			var n yaml.Node
+
+			if err := yaml.Unmarshal([]byte("["+strings.Join(val, ",")+"]"), &n); err != nil {
+				return config.Variable{}, fmt.Errorf("arg: failed unmarshal yaml:%w", err)
+			}
+
+			return config.Variable{
+				Name:     k,
+				Provider: p.Name(),
+				Value:    value.Decode(n.Decode),
+			}, nil
+		}
+	}
+
+	return config.Variable{Name: k, Provider: p.Name()}, config.ErrVariableNotFound
+}

provider/arg/provider_test.go

@@ -0,0 +1,48 @@
+package arg_test
+
+import (
+	"os"
+	"testing"
+	"time"
+
+	"gitoa.ru/go-4devs/config/provider/arg"
+	"gitoa.ru/go-4devs/config/test"
+)
+
+func TestProvider(t *testing.T) {
+	t.Parallel()
+
+	args := os.Args
+
+	defer func() {
+		os.Args = args
+	}()
+
+	os.Args = []string{
+		"main.go",
+		"--listen=8080",
+		"--config=config.hcl",
+		"--url=http://4devs.io",
+		"--url=https://4devs.io",
+		"--timeout=1m",
+		"--timeout=1h",
+		"--start-at=2010-01-02T15:04:05Z",
+		"--end-after=2009-01-02T15:04:05Z",
+		"--end-after=2008-01-02T15:04:05+03:00",
+	}
+	read := []test.Read{
+		test.NewRead("listen", 8080),
+		test.NewRead("config", "config.hcl"),
+		test.NewRead("start-at", test.Time("2010-01-02T15:04:05Z")),
+		test.NewReadUnmarshal("url", &[]string{"http://4devs.io", "https://4devs.io"}, &[]string{}),
+		test.NewReadUnmarshal("timeout", &[]time.Duration{time.Minute, time.Hour}, &[]time.Duration{}),
+		test.NewReadUnmarshal("end-after", &[]time.Time{
+			test.Time("2009-01-02T15:04:05Z"),
+			test.Time("2008-01-02T15:04:05+03:00"),
+		}, &[]time.Time{}),
+	}
+
+	prov := arg.New()
+
+	test.Run(t, prov, read)
+}

provider/env/provider.go

@@ -0,0 +1,61 @@
+package env
+
+import (
+	"context"
+	"os"
+	"strings"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/key"
+	"gitoa.ru/go-4devs/config/value"
+)
+
+var _ config.Provider = (*Provider)(nil)
+
+type Option func(*Provider)
+
+func WithKeyFactory(factory config.KeyFactory) Option {
+	return func(p *Provider) { p.key = factory }
+}
+
+func New(opts ...Option) *Provider {
+	p := Provider{
+		key: func(ctx context.Context, k config.Key) string {
+			return strings.ToUpper(key.NsAppName("_")(ctx, k))
+		},
+	}
+
+	for _, opt := range opts {
+		opt(&p)
+	}
+
+	return &p
+}
+
+type Provider struct {
+	key config.KeyFactory
+}
+
+func (p *Provider) Name() string {
+	return "env"
+}
+
+func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
+	return p.key(ctx, key) != ""
+}
+
+func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+	k := p.key(ctx, key)
+	if val, ok := os.LookupEnv(k); ok {
+		return config.Variable{
+			Name:     k,
+			Provider: p.Name(),
+			Value:    value.JString(val),
+		}, nil
+	}
+
+	return config.Variable{
+		Name:     k,
+		Provider: p.Name(),
+	}, config.ErrVariableNotFound
+}

provider/env/provider_test.go

@@ -0,0 +1,24 @@
+package env_test
+
+import (
+	"os"
+	"testing"
+
+	"gitoa.ru/go-4devs/config/provider/env"
+	"gitoa.ru/go-4devs/config/test"
+)
+
+func TestProvider(t *testing.T) {
+	t.Parallel()
+
+	os.Setenv("FDEVS_CONFIG_DSN", test.DSN)
+	os.Setenv("FDEVS_CONFIG_PORT", "8080")
+
+	provider := env.New()
+
+	read := []test.Read{
+		test.NewRead("dsn", test.DSN),
+		test.NewRead("port", 8080),
+	}
+	test.Run(t, provider, read)
+}

provider/etcd/provider.go

@@ -0,0 +1,113 @@
+package etcd
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/key"
+	"gitoa.ru/go-4devs/config/value"
+	pb "go.etcd.io/etcd/api/v3/mvccpb"
+	client "go.etcd.io/etcd/client/v3"
+)
+
+var (
+	_ config.Provider      = (*Provider)(nil)
+	_ config.WatchProvider = (*Provider)(nil)
+)
+
+type Client interface {
+	client.KV
+	client.Watcher
+}
+
+func NewProvider(client Client) *Provider {
+	p := Provider{
+		client: client,
+		key:    key.NsAppName("/"),
+	}
+
+	return &p
+}
+
+type Provider struct {
+	client Client
+	key    config.KeyFactory
+}
+
+func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
+	return p.key(ctx, key) != ""
+}
+
+func (p *Provider) Name() string {
+	return "etcd"
+}
+
+func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+	k := p.key(ctx, key)
+
+	resp, err := p.client.Get(ctx, k, client.WithPrefix())
+	if err != nil {
+		return config.Variable{}, fmt.Errorf("%w: key:%s, prov:%s", err, k, p.Name())
+	}
+
+	val, err := p.resolve(k, resp.Kvs)
+	if err != nil {
+		return config.Variable{}, fmt.Errorf("%w: key:%s, prov:%s", err, k, p.Name())
+	}
+
+	return val, nil
+}
+
+func (p *Provider) Watch(ctx context.Context, key config.Key, callback config.WatchCallback) error {
+	go func(ctx context.Context, key string, callback config.WatchCallback) {
+		watch := p.client.Watch(ctx, key, client.WithPrevKV(), client.WithPrefix())
+		for w := range watch {
+			kvs, olds := p.getEventKvs(w.Events)
+			if len(kvs) > 0 {
+				newVar, _ := p.resolve(key, kvs)
+				oldVar, _ := p.resolve(key, olds)
+				callback(ctx, oldVar, newVar)
+			}
+		}
+	}(ctx, p.key(ctx, key), callback)
+
+	return nil
+}
+
+func (p *Provider) getEventKvs(events []*client.Event) ([]*pb.KeyValue, []*pb.KeyValue) {
+	kvs := make([]*pb.KeyValue, 0, len(events))
+	old := make([]*pb.KeyValue, 0, len(events))
+
+	for i := range events {
+		kvs = append(kvs, events[i].Kv)
+		old = append(old, events[i].PrevKv)
+		log.Println(events[i].Type)
+	}
+
+	return kvs, old
+}
+
+func (p *Provider) resolve(key string, kvs []*pb.KeyValue) (config.Variable, error) {
+	for _, kv := range kvs {
+		switch {
+		case kv == nil:
+			return config.Variable{
+				Name:     key,
+				Provider: p.Name(),
+			}, nil
+		case string(kv.Key) == key:
+			return config.Variable{
+				Value:    value.JBytes(kv.Value),
+				Name:     key,
+				Provider: p.Name(),
+			}, nil
+		}
+	}
+
+	return config.Variable{
+		Name:     key,
+		Provider: p.Name(),
+	}, config.ErrVariableNotFound
+}

provider/etcd/provider_test.go

@@ -0,0 +1,119 @@
+package etcd_test
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/provider/etcd"
+	"gitoa.ru/go-4devs/config/test"
+)
+
+func TestProvider(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+
+	et, err := test.NewEtcd(ctx)
+	require.NoError(t, err)
+
+	provider := etcd.NewProvider(et)
+	read := []test.Read{
+		test.NewRead("db_dsn", test.DSN),
+		test.NewRead("duration", 12*time.Minute),
+		test.NewRead("port", 8080),
+		test.NewRead("maintain", true),
+		test.NewRead("start_at", test.Time("2020-01-02T15:04:05Z")),
+		test.NewRead("percent", .064),
+		test.NewRead("count", uint(2020)),
+		test.NewRead("int64", int64(2021)),
+		test.NewRead("uint64", int64(2022)),
+		test.NewReadConfig("config"),
+	}
+	test.Run(t, provider, read)
+}
+
+func value(cnt int32) string {
+	return fmt.Sprintf("test data: %d", cnt)
+}
+
+func TestWatcher(t *testing.T) {
+	t.Parallel()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	key := config.Key{
+		AppName:   "config",
+		Namespace: "fdevs",
+		Name:      "test_watch",
+	}
+
+	et, err := test.NewEtcd(ctx)
+	require.NoError(t, err)
+
+	defer func() {
+		_, err = et.KV.Delete(context.Background(), "fdevs/config/test_watch")
+		require.NoError(t, err)
+	}()
+
+	var cnt, cnt2 int32
+
+	prov := etcd.NewProvider(et)
+	wg := sync.WaitGroup{}
+	wg.Add(6)
+
+	watch := func(cnt *int32) func(ctx context.Context, oldVar, newVar config.Variable) {
+		return func(ctx context.Context, oldVar, newVar config.Variable) {
+			switch *cnt {
+			case 0:
+				assert.Equal(t, value(*cnt), newVar.Value.String())
+				assert.Nil(t, oldVar.Value)
+			case 1:
+				assert.Equal(t, value(*cnt), newVar.Value.String())
+				assert.Equal(t, value(*cnt-1), oldVar.Value.String())
+			case 2:
+				_, perr := newVar.Value.ParseString()
+				assert.NoError(t, perr)
+				assert.Equal(t, "", newVar.Value.String())
+				assert.Equal(t, value(*cnt-1), oldVar.Value.String())
+			default:
+				assert.Fail(t, "unexpected watch")
+			}
+
+			wg.Done()
+			atomic.AddInt32(cnt, 1)
+		}
+	}
+
+	err = prov.Watch(ctx, key, watch(&cnt))
+	err = prov.Watch(ctx, key, watch(&cnt2))
+	require.NoError(t, err)
+
+	time.AfterFunc(time.Second, func() {
+		_, err = et.KV.Put(ctx, "fdevs/config/test_watch", value(0))
+		require.NoError(t, err)
+		_, err = et.KV.Put(ctx, "fdevs/config/test_watch", value(1))
+		require.NoError(t, err)
+		_, err = et.KV.Delete(ctx, "fdevs/config/test_watch")
+		require.NoError(t, err)
+	})
+
+	time.AfterFunc(time.Second*10, func() {
+		assert.Fail(t, "failed watch after 5 sec")
+		cancel()
+	})
+
+	go func() {
+		wg.Wait()
+		cancel()
+	}()
+
+	<-ctx.Done()
+}

provider/ini/provider.go

@@ -0,0 +1,62 @@
+package ini
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/value"
+	"gopkg.in/ini.v1"
+)
+
+var _ config.Provider = (*Provider)(nil)
+
+func New(data *ini.File) *Provider {
+	return &Provider{
+		data: data,
+		resolve: func(ctx context.Context, key config.Key) (string, string) {
+			keys := strings.SplitN(key.Name, "/", 2)
+			if len(keys) == 1 {
+				return "", keys[0]
+			}
+
+			return keys[0], keys[1]
+		},
+	}
+}
+
+type Provider struct {
+	data    *ini.File
+	resolve func(ctx context.Context, key config.Key) (string, string)
+}
+
+func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
+	section, name := p.resolve(ctx, key)
+
+	return section != "" && name != ""
+}
+
+func (p *Provider) Name() string {
+	return "ini"
+}
+
+func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+	section, name := p.resolve(ctx, key)
+
+	iniSection, err := p.data.GetSection(section)
+	if err != nil {
+		return config.Variable{}, fmt.Errorf("%w: %s: %v", config.ErrVariableNotFound, p.Name(), err)
+	}
+
+	iniKey, err := iniSection.GetKey(name)
+	if err != nil {
+		return config.Variable{}, fmt.Errorf("%w: %s: %v", config.ErrVariableNotFound, p.Name(), err)
+	}
+
+	return config.Variable{
+		Name:     section + ":" + name,
+		Provider: p.Name(),
+		Value:    value.JString(iniKey.String()),
+	}, nil
+}

provider/ini/provider_test.go

@@ -0,0 +1,28 @@
+package ini_test
+
+import (
+	"testing"
+	"time"
+
+	"gitoa.ru/go-4devs/config/provider/ini"
+	"gitoa.ru/go-4devs/config/test"
+)
+
+func TestProvider(t *testing.T) {
+	t.Parallel()
+
+	file := test.NewINI()
+
+	read := []test.Read{
+		test.NewRead("project/PROJECT_BOARD_BASIC_KANBAN_TYPE", "To Do, In Progress, Done"),
+		test.NewRead("repository.editor/PREVIEWABLE_FILE_MODES", "markdown"),
+		test.NewRead("server/LOCAL_ROOT_URL", "http://0.0.0.0:3000/"),
+		test.NewRead("server/LFS_HTTP_AUTH_EXPIRY", 20*time.Minute),
+		test.NewRead("repository.pull-request/DEFAULT_MERGE_MESSAGE_SIZE", 5120),
+		test.NewRead("ui/SHOW_USER_EMAIL", true),
+		test.NewRead("cors/ENABLED", false),
+	}
+
+	prov := ini.New(file)
+	test.Run(t, prov, read)
+}

provider/json/provider.go

@@ -0,0 +1,66 @@
+package json
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+
+	"github.com/tidwall/gjson"
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/key"
+	"gitoa.ru/go-4devs/config/value"
+)
+
+var _ config.Provider = (*Provider)(nil)
+
+func New(json []byte, opts ...Option) *Provider {
+	provider := Provider{
+		key:  key.Name,
+		data: json,
+	}
+
+	for _, opt := range opts {
+		opt(&provider)
+	}
+
+	return &provider
+}
+
+func NewFile(path string, opts ...Option) (*Provider, error) {
+	file, err := ioutil.ReadFile(filepath.Clean(path))
+	if err != nil {
+		return nil, fmt.Errorf("%w: unable to read config file %#q: file not found or unreadable", err, path)
+	}
+
+	return New(file), nil
+}
+
+type Option func(*Provider)
+
+type Provider struct {
+	data []byte
+	key  config.KeyFactory
+}
+
+func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
+	return p.key(ctx, key) != ""
+}
+
+func (p *Provider) Name() string {
+	return "json"
+}
+
+func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+	path := p.key(ctx, key)
+
+	if val := gjson.GetBytes(p.data, path); val.Exists() {
+		return config.Variable{
+			Name:     path,
+			Provider: p.Name(),
+			Value:    value.JString(val.String()),
+		}, nil
+	}
+
+	return config.Variable{}, config.ErrVariableNotFound
+}

provider/json/provider_test.go

@@ -0,0 +1,27 @@
+package json_test
+
+import (
+	"testing"
+	"time"
+
+	provider "gitoa.ru/go-4devs/config/provider/json"
+	"gitoa.ru/go-4devs/config/test"
+)
+
+func TestProvider(t *testing.T) {
+	t.Parallel()
+
+	js := test.ReadFile("config.json")
+
+	prov := provider.New(js)
+	sl := []string{}
+	read := []test.Read{
+		test.NewRead("app.name.title", "config title"),
+		test.NewRead("app.name.timeout", time.Minute),
+		test.NewReadUnmarshal("app.name.var", &[]string{"name"}, &sl),
+		test.NewReadConfig("cfg"),
+		test.NewRead("app.name.success", true),
+	}
+
+	test.Run(t, prov, read)
+}

provider/toml/provider.go

@@ -0,0 +1,71 @@
+package toml
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/pelletier/go-toml"
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/key"
+	"gitoa.ru/go-4devs/config/value"
+)
+
+var _ config.Provider = (*Provider)(nil)
+
+func NewFile(file string, opts ...Option) (*Provider, error) {
+	tree, err := toml.LoadFile(file)
+	if err != nil {
+		return nil, fmt.Errorf("toml: failed load file: %w", err)
+	}
+
+	return configure(tree, opts...), nil
+}
+
+type Option func(*Provider)
+
+func configure(tree *toml.Tree, opts ...Option) *Provider {
+	p := &Provider{
+		tree: tree,
+		key:  key.Name,
+	}
+
+	for _, opt := range opts {
+		opt(p)
+	}
+
+	return p
+}
+
+func New(data []byte, opts ...Option) (*Provider, error) {
+	tree, err := toml.LoadBytes(data)
+	if err != nil {
+		return nil, fmt.Errorf("toml failed load data: %w", err)
+	}
+
+	return configure(tree, opts...), nil
+}
+
+type Provider struct {
+	tree *toml.Tree
+	key  config.KeyFactory
+}
+
+func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
+	return p.key(ctx, key) != ""
+}
+
+func (p *Provider) Name() string {
+	return "toml"
+}
+
+func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+	if k := p.key(ctx, key); p.tree.Has(k) {
+		return config.Variable{
+			Name:     k,
+			Provider: p.Name(),
+			Value:    Value{Value: value.Value{Val: p.tree.Get(k)}},
+		}, nil
+	}
+
+	return config.Variable{}, config.ErrVariableNotFound
+}

provider/toml/provider_test.go

@@ -0,0 +1,29 @@
+package toml_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"gitoa.ru/go-4devs/config/provider/toml"
+	"gitoa.ru/go-4devs/config/test"
+)
+
+func TestProvider(t *testing.T) {
+	t.Parallel()
+
+	prov, err := toml.NewFile(test.FixturePath("config.toml"))
+	require.NoError(t, err)
+
+	m := []int{}
+
+	read := []test.Read{
+		test.NewRead("database.server", "192.168.1.1"),
+		test.NewRead("title", "TOML Example"),
+		test.NewRead("servers.alpha.ip", "10.0.0.1"),
+		test.NewRead("database.enabled", true),
+		test.NewRead("database.connection_max", 5000),
+		test.NewReadUnmarshal("database.ports", &[]int{8001, 8001, 8002}, &m),
+	}
+
+	test.Run(t, prov, read)
+}

provider/toml/value.go

@@ -0,0 +1,41 @@
+package toml
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/value"
+)
+
+type Value struct {
+	value.Value
+}
+
+func (s Value) Int() int {
+	v, _ := s.ParseInt()
+
+	return v
+}
+
+func (s Value) ParseInt() (int, error) {
+	v, err := s.ParseInt64()
+	if err != nil {
+		return 0, fmt.Errorf("toml failed parce int: %w", err)
+	}
+
+	return int(v), nil
+}
+
+func (s Value) Unmarshal(target interface{}) error {
+	b, err := json.Marshal(s.Raw())
+	if err != nil {
+		return fmt.Errorf("%w: %s", config.ErrInvalidValue, err)
+	}
+
+	if err := json.Unmarshal(b, target); err != nil {
+		return fmt.Errorf("%w: %s", config.ErrInvalidValue, err)
+	}
+
+	return nil
+}

provider/vault/secret.go

@@ -0,0 +1,90 @@
+package vault
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/hashicorp/vault/api"
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/key"
+	"gitoa.ru/go-4devs/config/value"
+)
+
+var _ config.Provider = (*SecretKV2)(nil)
+
+type SecretOption func(*SecretKV2)
+
+func WithSecretResolve(f func(context.Context, config.Key) (string, string)) SecretOption {
+	return func(s *SecretKV2) { s.resolve = f }
+}
+
+func NewSecretKV2(client *api.Client, opts ...SecretOption) *SecretKV2 {
+	s := SecretKV2{
+		client:  client,
+		resolve: key.LastIndexField(":", "value", key.PrefixName("secret/data/", key.NsAppName("/"))),
+	}
+
+	for _, opt := range opts {
+		opt(&s)
+	}
+
+	return &s
+}
+
+type SecretKV2 struct {
+	client  *api.Client
+	resolve func(ctx context.Context, key config.Key) (string, string)
+}
+
+func (p *SecretKV2) IsSupport(ctx context.Context, key config.Key) bool {
+	path, _ := p.resolve(ctx, key)
+
+	return path != ""
+}
+
+func (p *SecretKV2) Name() string {
+	return "vault"
+}
+
+func (p *SecretKV2) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+	path, field := p.resolve(ctx, key)
+
+	s, err := p.client.Logical().Read(path)
+	if err != nil {
+		return config.Variable{}, fmt.Errorf("%w: path:%s, field:%s, provider:%s", err, path, field, p.Name())
+	}
+
+	if s == nil || len(s.Data) == 0 {
+		return config.Variable{}, fmt.Errorf("%w: path:%s, field:%s, provider:%s", config.ErrVariableNotFound, path, field, p.Name())
+	}
+
+	if len(s.Warnings) > 0 {
+		return config.Variable{},
+			fmt.Errorf("%w: warn: %s, path:%s, field:%s, provider:%s", config.ErrVariableNotFound, s.Warnings, path, field, p.Name())
+	}
+
+	d, ok := s.Data["data"].(map[string]interface{})
+	if !ok {
+		return config.Variable{}, fmt.Errorf("%w: path:%s, field:%s, provider:%s", config.ErrVariableNotFound, path, field, p.Name())
+	}
+
+	if val, ok := d[field]; ok {
+		return config.Variable{
+			Name:     path + field,
+			Provider: p.Name(),
+			Value:    value.JString(fmt.Sprint(val)),
+		}, nil
+	}
+
+	md, err := json.Marshal(d)
+	if err != nil {
+		return config.Variable{}, fmt.Errorf("%w: %s", config.ErrInvalidValue, err)
+	}
+
+	return config.Variable{
+		Name:     path + field,
+		Provider: p.Name(),
+		Value:    value.JBytes(md),
+	}, nil
+}

provider/vault/secret_test.go

@@ -0,0 +1,26 @@
+package vault_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"gitoa.ru/go-4devs/config/provider/vault"
+	"gitoa.ru/go-4devs/config/test"
+)
+
+func TestProvider(t *testing.T) {
+	t.Parallel()
+
+	cl, err := test.NewVault()
+	require.NoError(t, err)
+
+	provider := vault.NewSecretKV2(cl)
+
+	read := []test.Read{
+		test.NewReadConfig("database"),
+		test.NewRead("db:dsn", test.DSN),
+		test.NewRead("db:timeout", time.Minute),
+	}
+	test.Run(t, provider, read)
+}

provider/watcher/provider.go

@@ -0,0 +1,71 @@
+package watcher
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"gitoa.ru/go-4devs/config"
+)
+
+var (
+	_ config.Provider      = (*Provider)(nil)
+	_ config.WatchProvider = (*Provider)(nil)
+)
+
+func New(duration time.Duration, provider config.Provider, opts ...Option) *Provider {
+	p := &Provider{
+		Provider: provider,
+		ticker:   time.NewTicker(duration),
+		logger: func(_ context.Context, msg string) {
+			log.Print(msg)
+		},
+	}
+
+	for _, opt := range opts {
+		opt(p)
+	}
+
+	return p
+}
+
+func WithLogger(l func(context.Context, string)) Option {
+	return func(p *Provider) {
+		p.logger = l
+	}
+}
+
+type Option func(*Provider)
+
+type Provider struct {
+	config.Provider
+	ticker *time.Ticker
+	logger func(context.Context, string)
+}
+
+func (p *Provider) Watch(ctx context.Context, key config.Key, callback config.WatchCallback) error {
+	oldVar, err := p.Provider.Read(ctx, key)
+	if err != nil {
+		return fmt.Errorf("%s: failed watch variable: %w", p.Provider.Name(), err)
+	}
+
+	go func() {
+		for {
+			select {
+			case <-p.ticker.C:
+				newVar, err := p.Provider.Read(ctx, key)
+				if err != nil {
+					p.logger(ctx, err.Error())
+				} else if !newVar.IsEquals(oldVar) {
+					callback(ctx, oldVar, newVar)
+					oldVar = newVar
+				}
+			case <-ctx.Done():
+				return
+			}
+		}
+	}()
+
+	return nil
+}

provider/watcher/provider_test.go

@@ -0,0 +1,58 @@
+package watcher_test
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/provider/watcher"
+	"gitoa.ru/go-4devs/config/value"
+)
+
+type provider struct {
+	cnt int32
+}
+
+func (p *provider) Name() string {
+	return "test"
+}
+
+func (p *provider) Read(ctx context.Context, k config.Key) (config.Variable, error) {
+	p.cnt++
+
+	return config.Variable{
+		Name:  "tmpname",
+		Value: value.JString(fmt.Sprint(p.cnt)),
+	}, nil
+}
+
+func TestWatcher(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+	prov := &provider{}
+
+	w := watcher.New(time.Second, prov)
+	wg := sync.WaitGroup{}
+	wg.Add(2)
+
+	var cnt int32
+
+	err := w.Watch(
+		ctx,
+		config.Key{Name: "tmpname"},
+		func(ctx context.Context, oldVar, newVar config.Variable) {
+			atomic.AddInt32(&cnt, 1)
+			wg.Done()
+		},
+	)
+	require.NoError(t, err)
+	wg.Wait()
+
+	require.Equal(t, int32(2), cnt)
+}

provider/yaml/file.go

@@ -0,0 +1,57 @@
+package yaml
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+
+	"gitoa.ru/go-4devs/config"
+	"gopkg.in/yaml.v3"
+)
+
+func WithFileKeyFactory(f func(context.Context, config.Key) []string) FileOption {
+	return func(p *File) {
+		p.key = f
+	}
+}
+
+type FileOption func(*File)
+
+func NewFile(name string, opts ...FileOption) *File {
+	f := File{
+		file: name,
+		key:  keyFactory,
+	}
+
+	for _, opt := range opts {
+		opt(&f)
+	}
+
+	return &f
+}
+
+type File struct {
+	file string
+	key  func(context.Context, config.Key) []string
+}
+
+func (p *File) Name() string {
+	return "yaml_file"
+}
+
+func (p *File) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+	in, err := ioutil.ReadFile(p.file)
+	if err != nil {
+		return config.Variable{}, fmt.Errorf("yaml_file: read error: %w", err)
+	}
+
+	var n yaml.Node
+	if err = yaml.Unmarshal(in, &n); err != nil {
+		return config.Variable{}, fmt.Errorf("yaml_file: unmarshal error: %w", err)
+	}
+
+	data := node{Node: &n}
+	k := p.key(ctx, key)
+
+	return data.read(p.Name(), k)
+}

provider/yaml/provider.go

@@ -0,0 +1,88 @@
+package yaml
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/value"
+	"gopkg.in/yaml.v3"
+)
+
+var _ config.Provider = (*Provider)(nil)
+
+func keyFactory(ctx context.Context, key config.Key) []string {
+	return strings.Split(key.Name, "/")
+}
+
+func New(yml []byte, opts ...Option) (*Provider, error) {
+	var data yaml.Node
+	if err := yaml.Unmarshal(yml, &data); err != nil {
+		return nil, fmt.Errorf("yaml: unmarshal err: %w", err)
+	}
+
+	p := Provider{
+		key:  keyFactory,
+		data: node{Node: &data},
+	}
+
+	for _, opt := range opts {
+		opt(&p)
+	}
+
+	return &p, nil
+}
+
+type Option func(*Provider)
+
+type Provider struct {
+	data node
+	key  func(context.Context, config.Key) []string
+}
+
+func (p *Provider) Name() string {
+	return "yaml"
+}
+
+func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+	k := p.key(ctx, key)
+
+	return p.data.read(p.Name(), k)
+}
+
+type node struct {
+	*yaml.Node
+}
+
+func (n *node) read(name string, k []string) (config.Variable, error) {
+	val, err := getData(n.Node.Content[0].Content, k)
+	if err != nil {
+		if errors.Is(err, config.ErrVariableNotFound) {
+			return config.Variable{}, fmt.Errorf("%w: %s", config.ErrVariableNotFound, name)
+		}
+
+		return config.Variable{}, fmt.Errorf("%w: %s", err, name)
+	}
+
+	return config.Variable{
+		Name:     strings.Join(k, "."),
+		Provider: name,
+		Value:    value.Decode(val),
+	}, nil
+}
+
+func getData(node []*yaml.Node, keys []string) (func(interface{}) error, error) {
+	for i := len(node) - 1; i > 0; i -= 2 {
+		if node[i-1].Value == keys[0] {
+			if len(keys) > 1 {
+				return getData(node[i].Content, keys[1:])
+			}
+
+			return node[i].Decode, nil
+		}
+	}
+
+	return nil, config.ErrVariableNotFound
+}

provider/yaml/provider_test.go

@@ -0,0 +1,26 @@
+package yaml_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	provider "gitoa.ru/go-4devs/config/provider/yaml"
+	"gitoa.ru/go-4devs/config/test"
+)
+
+func TestProvider(t *testing.T) {
+	t.Parallel()
+
+	prov, err := provider.New(test.ReadFile("config.yaml"))
+	require.Nil(t, err)
+
+	read := []test.Read{
+		test.NewRead("duration_var", 21*time.Minute),
+		test.NewRead("app/name/bool_var", true),
+		test.NewRead("time_var", test.Time("2020-01-02T15:04:05Z")),
+		test.NewReadConfig("cfg"),
+	}
+
+	test.Run(t, prov, read)
+}