Fix merge config map provider to close the watchers (#4570)

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

CHANGELOG.md

@@ -14,6 +14,10 @@
   - `service.telemetry.metrics.level` and `service.telemetry.metrics.address`
     should be used to configure collector self-metrics.
 
+## 🧰 Bug fixes 🧰
+
+- Fix merge config map provider to close the watchers #4570
+
 ## v0.41.0 Beta
 
 ## 🛑 Breaking changes 🛑

config/configmapprovider/merge.go

@@ -36,6 +36,7 @@ func NewMerge(ps ...Provider) Provider {
 }
 
 func (mp *mergeMapProvider) Retrieve(ctx context.Context, onChange func(*ChangeEvent)) (Retrieved, error) {
+	var retrs []Retrieved
 	retCfgMap := config.NewMap()
 	for _, p := range mp.providers {
 		retr, err := p.Retrieve(ctx, onChange)
@@ -49,8 +50,15 @@ func (mp *mergeMapProvider) Retrieve(ctx context.Context, onChange func(*ChangeE
 		if err = retCfgMap.Merge(cfgMap); err != nil {
 			return nil, err
 		}
+		retrs = append(retrs, retr)
 	}
-	return &simpleRetrieved{confMap: retCfgMap}, nil
+	return &simpleRetrieved{confMap: retCfgMap, closeFunc: func(ctxF context.Context) error {
+		var err error
+		for _, ret := range retrs {
+			err = multierr.Append(err, ret.Close(ctxF))
+		}
+		return err
+	}}, nil
 }
 
 func (mp *mergeMapProvider) Shutdown(ctx context.Context) error {

config/configmapprovider/merge_test.go

@@ -26,26 +26,35 @@ import (
 )
 
 func TestMerge_GetError(t *testing.T) {
-	pl := NewMerge(&errProvider{err: nil}, &errProvider{errors.New("my error")})
+	pl := NewMerge(&errProvider{err: nil}, &errProvider{err: errors.New("my error")})
 	require.NotNil(t, pl)
 	cp, err := pl.Retrieve(context.Background(), nil)
 	assert.Error(t, err)
 	assert.Nil(t, cp)
 }
 
 func TestMerge_CloseError(t *testing.T) {
-	pl := NewMerge(&errProvider{err: nil}, &errProvider{errors.New("my error")})
+	pl := NewMerge(&errProvider{err: nil}, &errProvider{closeErr: errors.New("my error")})
+	require.NotNil(t, pl)
+	cp, err := pl.Retrieve(context.Background(), nil)
+	assert.NoError(t, err)
+	assert.Error(t, cp.Close(context.Background()))
+}
+
+func TestMerge_ShutdownError(t *testing.T) {
+	pl := NewMerge(&errProvider{err: nil}, &errProvider{err: errors.New("my error")})
 	require.NotNil(t, pl)
 	assert.Error(t, pl.Shutdown(context.Background()))
 }
 
 type errProvider struct {
-	err error
+	err      error
+	closeErr error
 }
 
 func (epl *errProvider) Retrieve(context.Context, func(*ChangeEvent)) (Retrieved, error) {
 	if epl.err == nil {
-		return &simpleRetrieved{confMap: config.NewMap()}, nil
+		return &simpleRetrieved{confMap: config.NewMap(), closeFunc: func(context.Context) error { return epl.closeErr }}, nil
 	}
 	return nil, epl.err
 }

config/configmapprovider/simple.go

@@ -20,15 +20,21 @@ import (
 	"go.opentelemetry.io/collector/config"
 )
 
+type closeFunc func(ctx context.Context) error
+
 // TODO: This probably will make sense to be exported, but needs better name and documentation.
 type simpleRetrieved struct {
+	closeFunc
 	confMap *config.Map
 }
 
-func (sr *simpleRetrieved) Get(ctx context.Context) (*config.Map, error) {
+func (sr *simpleRetrieved) Get(context.Context) (*config.Map, error) {
 	return sr.confMap, nil
 }
 
 func (sr *simpleRetrieved) Close(ctx context.Context) error {
-	return nil
+	if sr.closeFunc == nil {
+		return nil
+	}
+	return sr.closeFunc(ctx)
 }