Merge pull request 'add etcd provider' (#8) from etcd into master

Reviewed-on: #8

.drone.yml

@@ -5,7 +5,6 @@ name: default
 environment:
   VAULT_DEV_LISTEN_ADDRESS: http://vault:8200
   VAULT_DEV_ROOT_TOKEN_ID: dev
-  FDEVS_CONFIG_ETCD_HOST: etcd:2379
 
 steps:
 - name: test 
@@ -91,3 +90,32 @@ steps:
   - cd provider/toml
   - golangci-lint run
 
+
+---
+kind: pipeline
+type: docker
+name: etcd
+
+environment:
+  FDEVS_CONFIG_ETCD_HOST: etcd:2379
+
+services:
+  - name: etcd
+    image: bitnami/etcd:3.5.11
+    environment:
+      ALLOW_NONE_AUTHENTICATION: yes
+
+steps:
+- name: test 
+  image: golang
+  failure: ignore # runtime/cgo: pthread_create failed: Operation not permitted
+  commands:
+  - cd provider/etcd
+  - go test ./... 
+
+- name: golangci-lint
+  image: golangci/golangci-lint:v1.55
+  commands:
+  - cd provider/etcd
+  - golangci-lint run
+

provider/etcd/etcd_test.go

@@ -0,0 +1,48 @@
+package etcd_test
+
+import (
+	"context"
+	"os"
+	"time"
+
+	client "go.etcd.io/etcd/client/v3"
+)
+
+const ConfigJSON = `{"duration":1260000000000,"enabled":true}`
+
+func NewEtcd(ctx context.Context) (*client.Client, error) {
+	dsn, ok := os.LookupEnv("FDEVS_CONFIG_ETCD_HOST")
+	if !ok {
+		dsn = "127.0.0.1:2379"
+	}
+
+	et, err := client.New(client.Config{
+		Endpoints:   []string{dsn},
+		DialTimeout: time.Second,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	values := map[string]string{
+		"fdevs/config/db_dsn":   "pgsql://user@pass:127.0.0.1:5432",
+		"fdevs/config/duration": "12m",
+		"fdevs/config/port":     "8080",
+		"fdevs/config/maintain": "true",
+		"fdevs/config/start_at": "2020-01-02T15:04:05Z",
+		"fdevs/config/percent":  "0.064",
+		"fdevs/config/count":    "2020",
+		"fdevs/config/int64":    "2021",
+		"fdevs/config/uint64":   "2022",
+		"fdevs/config/config":   ConfigJSON,
+	}
+
+	for name, val := range values {
+		_, err = et.KV.Put(ctx, name, val)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return et, nil
+}

provider/etcd/go.mod

@@ -0,0 +1,32 @@
+module gitoa.ru/go-4devs/config/provider/etcd
+
+go 1.21
+
+require (
+	github.com/stretchr/testify v1.8.4
+	gitoa.ru/go-4devs/config v0.0.2
+	go.etcd.io/etcd/api/v3 v3.5.11
+	go.etcd.io/etcd/client/v3 v3.5.11
+)
+
+require (
+	github.com/coreos/go-semver v0.3.0 // indirect
+	github.com/coreos/go-systemd/v22 v22.3.2 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.etcd.io/etcd/client/pkg/v3 v3.5.11 // indirect
+	go.uber.org/atomic v1.7.0 // indirect
+	go.uber.org/multierr v1.6.0 // indirect
+	go.uber.org/zap v1.17.0 // indirect
+	golang.org/x/net v0.17.0 // indirect
+	golang.org/x/sys v0.13.0 // indirect
+	golang.org/x/text v0.13.0 // indirect
+	google.golang.org/genproto v0.0.0-20230822172742-b8732ec3820d // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20230822172742-b8732ec3820d // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20230822172742-b8732ec3820d // indirect
+	google.golang.org/grpc v1.59.0 // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

provider/etcd/go.sum

@@ -0,0 +1,97 @@
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+github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
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provider/etcd/provider.go

@@ -0,0 +1,116 @@
+package etcd
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/value"
+	pb "go.etcd.io/etcd/api/v3/mvccpb"
+	client "go.etcd.io/etcd/client/v3"
+)
+
+const (
+	Name      = "etcd"
+	Separator = "/"
+)
+
+var (
+	_ config.Provider      = (*Provider)(nil)
+	_ config.WatchProvider = (*Provider)(nil)
+)
+
+type Client interface {
+	client.KV
+	client.Watcher
+}
+
+func New(namespace, appName string, client Client) *Provider {
+	prov := Provider{
+		client: client,
+		key: func(s ...string) string {
+			return strings.Join(s, Separator)
+		},
+		name:   Name,
+		prefix: namespace + Separator + appName,
+	}
+
+	return &prov
+}
+
+type Provider struct {
+	client Client
+	key    func(...string) string
+	name   string
+	prefix string
+	log    func(context.Context, string, ...any)
+}
+
+func (p *Provider) Name() string {
+	return p.name
+}
+
+func (p *Provider) Key(s []string) string {
+	return p.prefix + Separator + p.key(s...)
+}
+
+func (p *Provider) Value(ctx context.Context, path ...string) (config.Value, error) {
+	name := p.Key(path)
+
+	resp, err := p.client.Get(ctx, name, client.WithPrefix())
+	if err != nil {
+		return nil, fmt.Errorf("%w: key:%s, prov:%s", err, name, p.Name())
+	}
+
+	val, err := p.resolve(name, resp.Kvs)
+	if err != nil {
+		return nil, fmt.Errorf("%w: key:%s, prov:%s", err, name, p.Name())
+	}
+
+	return val, nil
+}
+
+func (p *Provider) Watch(ctx context.Context, callback config.WatchCallback, path ...string) 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)
+
+				if err := callback(ctx, oldVar, newVar); err != nil {
+					p.log(ctx, "watch callback[%v] %v:%v", p.Name(), path, err)
+				}
+			}
+		}
+	}(ctx, p.Key(path), 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)
+	}
+
+	return kvs, old
+}
+
+func (p *Provider) resolve(key string, kvs []*pb.KeyValue) (config.Value, error) {
+	for _, kv := range kvs {
+		switch {
+		case kv == nil:
+			return nil, nil
+		case string(kv.Key) == key:
+			return value.JBytes(kv.Value), nil
+		}
+	}
+
+	return nil, fmt.Errorf("%w: name %s", config.ErrValueNotFound, key)
+}

provider/etcd/provider_example_test.go

@@ -0,0 +1,121 @@
+package etcd_test
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"sync"
+	"time"
+
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/provider/etcd"
+)
+
+func ExampleClient_Value() {
+	const (
+		namespace = "fdevs"
+		appName   = "config"
+	)
+
+	ctx := context.Background()
+
+	// configure etcd client
+	etcdClient, err := NewEtcd(ctx)
+	if err != nil {
+		log.Print(err)
+
+		return
+	}
+
+	config, err := config.New(
+		etcd.New(namespace, appName, etcdClient),
+	)
+	if err != nil {
+		log.Print(err)
+
+		return
+	}
+
+	enabled, err := config.Value(ctx, "maintain")
+	if err != nil {
+		log.Print("maintain ", err)
+
+		return
+	}
+
+	fmt.Printf("maintain from etcd: %v\n", enabled.Bool())
+	// Output:
+	// maintain from etcd: true
+}
+
+func ExampleClient_Watch() {
+	const (
+		namespace = "fdevs"
+		appName   = "config"
+	)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	// configure etcd client
+	etcdClient, err := NewEtcd(ctx)
+	if err != nil {
+		log.Print(err)
+
+		return
+	}
+
+	_, err = etcdClient.KV.Put(ctx, "fdevs/config/example_db_dsn", "pgsql://user@pass:127.0.0.1:5432")
+	if err != nil {
+		log.Print(err)
+
+		return
+	}
+
+	defer func() {
+		cancel()
+
+		if _, err = etcdClient.KV.Delete(context.Background(), "fdevs/config/example_db_dsn"); err != nil {
+			log.Print(err)
+
+			return
+		}
+	}()
+
+	watcher, err := config.New(
+		etcd.New(namespace, appName, etcdClient),
+	)
+	if err != nil {
+		log.Print(err)
+
+		return
+	}
+
+	wg := sync.WaitGroup{}
+	wg.Add(1)
+
+	err = watcher.Watch(ctx, func(_ context.Context, oldVar, newVar config.Value) error {
+		fmt.Println("update example_db_dsn old: ", oldVar.String(), " new:", newVar.String())
+		wg.Done()
+
+		return nil
+	}, "example_db_dsn")
+	if err != nil {
+		log.Print(err)
+
+		return
+	}
+
+	time.AfterFunc(time.Second, func() {
+		if _, err := etcdClient.KV.Put(ctx, "fdevs/config/example_db_dsn", "mysql://localhost:5432"); err != nil {
+			log.Print(err)
+
+			return
+		}
+	})
+
+	wg.Wait()
+
+	// Output:
+	// update example_db_dsn old:  pgsql://user@pass:127.0.0.1:5432  new: mysql://localhost:5432
+}

provider/etcd/provider_test.go

@@ -0,0 +1,118 @@
+package etcd_test
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"gitoa.ru/go-4devs/config"
+	"gitoa.ru/go-4devs/config/provider/etcd"
+	"gitoa.ru/go-4devs/config/test"
+	"gitoa.ru/go-4devs/config/test/require"
+)
+
+func TestProvider(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+
+	et, err := NewEtcd(ctx)
+	require.NoError(t, err)
+
+	provider := etcd.New("fdevs", "config", et)
+	read := []test.Read{
+		test.NewRead(test.DSN, "db_dsn"),
+		test.NewRead(12*time.Minute, "duration"),
+		test.NewRead(8080, "port"),
+		test.NewRead(true, "maintain"),
+		test.NewRead(test.Time("2020-01-02T15:04:05Z"), "start_at"),
+		test.NewRead(.064, "percent"),
+		test.NewRead(uint(2020), "count"),
+		test.NewRead(int64(2021), "int64"),
+		test.NewRead(int64(2022), "uint64"),
+		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 := "test_watch"
+
+	et, err := 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.New("fdevs", "config", et)
+	wg := sync.WaitGroup{}
+	wg.Add(6)
+
+	watch := func(cnt *int32) config.WatchCallback {
+		return func(ctx context.Context, oldVar, newVar config.Value) error {
+			switch *cnt {
+			case 0:
+				assert.Equal(t, value(*cnt), newVar.String())
+				assert.Nil(t, oldVar)
+			case 1:
+				assert.Equal(t, value(*cnt), newVar.String())
+				assert.Equal(t, value(*cnt-1), oldVar.String())
+			case 2:
+				_, perr := newVar.ParseString()
+				require.NoError(t, perr)
+				assert.Equal(t, "", newVar.String())
+				assert.Equal(t, value(*cnt-1), oldVar.String())
+			default:
+				t.Error("unexpected watch")
+				t.Fail()
+			}
+
+			wg.Done()
+			atomic.AddInt32(cnt, 1)
+
+			return nil
+		}
+	}
+
+	err = prov.Watch(ctx, watch(&cnt), key)
+	err = prov.Watch(ctx, watch(&cnt2), key)
+	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()
+}