Move MapProvider to config, split providers per own package

This PR:
1. moves the `configmapprovider.Provider` to `config.MapProvider` and related structs.
2. every provider (env, file, yaml) are split in their own packages to help open-telemetry#4759.

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

CHANGELOG.md

@@ -10,6 +10,7 @@
 
 ### 🚩 Deprecations 🚩
 
+- Move MapProvider to config, split providers in their own package (#5030)
 - API related to `pdata.AttributeValue` is deprecated in favor of `pdata.Value` (#4975)
   - `pdata.AttributeValue` struct is deprecated in favor of `pdata.Value`
   - `pdata.AttributeValueType` type is deprecated in favor of `pdata.ValueType`

config/configmapprovider/expand_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/collector/config"
+	"go.opentelemetry.io/collector/config/filemapprovider"
 )
 
 func TestNewExpandConverter(t *testing.T) {
@@ -116,7 +117,7 @@ func TestNewExpandConverter_EscapedEnvVars(t *testing.T) {
 }
 
 func loadConfigMap(fileName string) (*config.Map, error) {
-	ret, err := NewFile().Retrieve(context.Background(), "file:"+fileName, nil)
+	ret, err := filemapprovider.New().Retrieve(context.Background(), "file:"+fileName, nil)
 	if err != nil {
 		return nil, err
 	}

config/configmapprovider/provider.go

@@ -15,85 +15,32 @@
 package configmapprovider // import "go.opentelemetry.io/collector/config/configmapprovider"
 
 import (
-	"context"
-
 	"go.opentelemetry.io/collector/config"
+	"go.opentelemetry.io/collector/config/envmapprovider"
+	"go.opentelemetry.io/collector/config/filemapprovider"
+	"go.opentelemetry.io/collector/config/yamlmapprovider"
 )
 
-// Provider is an interface that helps to retrieve a config map and watch for any
-// changes to the config map. Implementations may load the config from a file,
-// a database or any other source.
-//
-// The typical usage is the following:
-//
-//		r, err := mapProvider.Retrieve("file:/path/to/config")
-//      // Use r.Map; wait for onChange() to be called.
-//		r.Close()
-//		r, err = mapProvider.Retrieve("file:/path/to/config")
-//      // Use r.Map; wait for onChange() to be called.
-//		r.Close()
-//		// repeat retrieve/wait/close cycle until it is time to shut down the Collector process.
-//		// ...
-//		mapProvider.Shutdown()
-type Provider interface {
-	// Retrieve goes to the configuration source and retrieves the selected data which
-	// contains the value to be injected in the configuration and the corresponding watcher that
-	// will be used to monitor for updates of the retrieved value.
-	//
-	// `location` must follow the "<scheme>:<opaque_data>" format. This format is compatible
-	// with the URI definition (see https://datatracker.ietf.org/doc/html/rfc3986). The "<scheme>"
-	// must be always included in the `location`. The scheme supported by any provider MUST be at
-	// least 2 characters long to avoid conflicting with a driver-letter identifier as specified
-	// in https://tools.ietf.org/id/draft-kerwin-file-scheme-07.html#syntax.
-	//
-	// `watcher` callback is called when the config changes. watcher may be called from
-	// a different go routine. After watcher is called Retrieved.Get should be called
-	// to get the new config. See description of Retrieved for more details.
-	// watcher may be nil, which indicates that the caller is not interested in
-	// knowing about the changes.
-	//
-	// If ctx is cancelled should return immediately with an error.
-	// Should never be called concurrently with itself or with Shutdown.
-	Retrieve(ctx context.Context, location string, watcher WatcherFunc) (Retrieved, error)
+// Deprecated: [v0.48.0] use envmapprovider.New
+var NewFile = envmapprovider.New
 
-	// Shutdown signals that the configuration for which this Provider was used to
-	// retrieve values is no longer in use and the Provider should close and release
-	// any resources that it may have created.
-	//
-	// This method must be called when the Collector service ends, either in case of
-	// success or error. Retrieve cannot be called after Shutdown.
-	//
-	// Should never be called concurrently with itself or with Retrieve.
-	// If ctx is cancelled should return immediately with an error.
-	Shutdown(ctx context.Context) error
-}
+// Deprecated: [v0.48.0] use filemapprovider.New
+var NewEnv = filemapprovider.New
 
-type WatcherFunc func(*ChangeEvent)
+// Deprecated: [v0.48.0] use yamlmapprovider.New
+var NewYAML = yamlmapprovider.New
 
-// ChangeEvent describes the particular change event that happened with the config.
-// TODO: see if this can be eliminated.
-type ChangeEvent struct {
-	// Error is nil if the config is changed and needs to be re-fetched.
-	// Any non-nil error indicates that there was a problem with watching the config changes.
-	Error error
-}
+// Deprecated: [v0.48.0] use config.MapProvider
+type Provider = config.MapProvider
 
-// Retrieved holds the result of a call to the Retrieve method of a Provider object.
-type Retrieved struct {
-	Map *config.Map
+// Deprecated: [v0.48.0] use config.WatcherFunc
+type WatcherFunc = config.WatcherFunc
 
-	// CloseFunc specifies a function to be invoked when the configuration for which it was
-	// used to retrieve values is no longer in use and should close and release any watchers
-	// that it may have created.
-	//
-	// If nil, then nothing to be closed.
-	CloseFunc
-}
+// Deprecated: [v0.48.0] use config.ChangeEvent
+type ChangeEvent = config.ChangeEvent
 
-// CloseFunc a function to close and release any watchers that it may have created.
-//
-// Should block until all resources are closed, and guarantee that `onChange` is not
-// going to be called after it returns except when `ctx` is cancelled.
-//
-// Should never be called concurrently with itself.
-type CloseFunc func(context.Context) error
+// Deprecated: [v0.48.0] use config.Retrieved
+type Retrieved = config.Retrieved
+
+// Deprecated: [v0.48.0] use config.CloseFunc
+type CloseFunc = config.CloseFunc

config/configtest/configtest.go

@@ -24,15 +24,15 @@ import (
 	"go.uber.org/multierr"
 
 	"go.opentelemetry.io/collector/config"
-	"go.opentelemetry.io/collector/config/configmapprovider"
+	"go.opentelemetry.io/collector/config/filemapprovider"
 )
 
 // The regular expression for valid config field tag.
 var configFieldTagRegExp = regexp.MustCompile("^[a-z0-9][a-z0-9_]*$")
 
 // LoadConfigMap loads a config.Map from file, and does NOT validate the configuration.
 func LoadConfigMap(fileName string) (*config.Map, error) {
-	ret, err := configmapprovider.NewFile().Retrieve(context.Background(), "file:"+fileName, nil)
+	ret, err := filemapprovider.New().Retrieve(context.Background(), "file:"+fileName, nil)
 	return ret.Map, err
 }
 

config/configmapprovider/env.go → config/envmapprovider/env.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package configmapprovider // import "go.opentelemetry.io/collector/config/configmapprovider"
+package envmapprovider // import "go.opentelemetry.io/collector/config/envmapprovider"
 
 import (
 	"context"
@@ -29,26 +29,26 @@ const envSchemeName = "env"
 
 type envMapProvider struct{}
 
-// NewEnv returns a new Provider that reads the configuration from the given environment variable.
+// New returns a new config.MapProvider that reads the configuration from the given environment variable.
 //
 // This Provider supports "env" scheme, and can be called with a selector:
 // `env:NAME_OF_ENVIRONMENT_VARIABLE`
-func NewEnv() Provider {
+func New() config.MapProvider {
 	return &envMapProvider{}
 }
 
-func (emp *envMapProvider) Retrieve(_ context.Context, location string, _ WatcherFunc) (Retrieved, error) {
+func (emp *envMapProvider) Retrieve(_ context.Context, location string, _ config.WatcherFunc) (config.Retrieved, error) {
 	if !strings.HasPrefix(location, envSchemeName+":") {
-		return Retrieved{}, fmt.Errorf("%v location is not supported by %v provider", location, envSchemeName)
+		return config.Retrieved{}, fmt.Errorf("%v location is not supported by %v provider", location, envSchemeName)
 	}
 
 	content := os.Getenv(location[len(envSchemeName)+1:])
 	var data map[string]interface{}
 	if err := yaml.Unmarshal([]byte(content), &data); err != nil {
-		return Retrieved{}, fmt.Errorf("unable to parse yaml: %w", err)
+		return config.Retrieved{}, fmt.Errorf("unable to parse yaml: %w", err)
 	}
 
-	return Retrieved{Map: config.NewMapFromStringMap(data)}, nil
+	return config.Retrieved{Map: config.NewMapFromStringMap(data)}, nil
 }
 
 func (*envMapProvider) Shutdown(context.Context) error {

config/configmapprovider/env_test.go → config/envmapprovider/env_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package configmapprovider
+package envmapprovider
 
 import (
 	"context"
@@ -28,26 +28,26 @@ import (
 
 const envSchemePrefix = envSchemeName + ":"
 
-func TestEnv_EmptyName(t *testing.T) {
-	env := NewEnv()
+func TestEmptyName(t *testing.T) {
+	env := New()
 	_, err := env.Retrieve(context.Background(), "", nil)
 	require.Error(t, err)
 	assert.NoError(t, env.Shutdown(context.Background()))
 }
 
-func TestEnv_UnsupportedScheme(t *testing.T) {
-	env := NewEnv()
-	_, err := env.Retrieve(context.Background(), "http://", nil)
+func TestUnsupportedScheme(t *testing.T) {
+	env := New()
+	_, err := env.Retrieve(context.Background(), "https://", nil)
 	assert.Error(t, err)
 	assert.NoError(t, env.Shutdown(context.Background()))
 }
 
-func TestEnv_InvalidYaml(t *testing.T) {
+func TestInvalidYaml(t *testing.T) {
 	bytes, err := os.ReadFile(filepath.Join("testdata", "invalid-yaml.yaml"))
 	require.NoError(t, err)
 	const envName = "invalid-yaml"
 	t.Setenv(envName, string(bytes))
-	env := NewEnv()
+	env := New()
 	_, err = env.Retrieve(context.Background(), envSchemePrefix+envName, nil)
 	assert.Error(t, err)
 	assert.NoError(t, env.Shutdown(context.Background()))
@@ -59,7 +59,7 @@ func TestEnv(t *testing.T) {
 	const envName = "default-config"
 	t.Setenv(envName, string(bytes))
 
-	env := NewEnv()
+	env := New()
 	ret, err := env.Retrieve(context.Background(), envSchemePrefix+envName, nil)
 	require.NoError(t, err)
 	expectedMap := config.NewMapFromStringMap(map[string]interface{}{

config/envmapprovider/testdata/default-config.yaml

@@ -0,0 +1,5 @@
+processors:
+  batch:
+exporters:
+  otlp:
+    endpoint: "localhost:4317"

config/configmapprovider/file.go → config/filemapprovider/file.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package configmapprovider // import "go.opentelemetry.io/collector/config/configmapprovider"
+package filemapprovider // import "go.opentelemetry.io/collector/config/filemapprovider"
 
 import (
 	"context"
@@ -30,7 +30,7 @@ const fileSchemeName = "file"
 
 type fileMapProvider struct{}
 
-// NewFile returns a new Provider that reads the configuration from a file.
+// New returns a new config.MapProvider that reads the configuration from a file.
 //
 // This Provider supports "file" scheme, and can be called with a "location" that follows:
 //   file-location = "file:" local-path
@@ -43,27 +43,27 @@ type fileMapProvider struct{}
 // `file:/path/to/file` - absolute path (unix, windows)
 // `file:c:/path/to/file` - absolute path including drive-letter (windows)
 // `file:c:\path\to\file` - absolute path including drive-letter (windows)
-func NewFile() Provider {
+func New() config.MapProvider {
 	return &fileMapProvider{}
 }
 
-func (fmp *fileMapProvider) Retrieve(_ context.Context, location string, _ WatcherFunc) (Retrieved, error) {
+func (fmp *fileMapProvider) Retrieve(_ context.Context, location string, _ config.WatcherFunc) (config.Retrieved, error) {
 	if !strings.HasPrefix(location, fileSchemeName+":") {
-		return Retrieved{}, fmt.Errorf("%v location is not supported by %v provider", location, fileSchemeName)
+		return config.Retrieved{}, fmt.Errorf("%v location is not supported by %v provider", location, fileSchemeName)
 	}
 
 	// Clean the path before using it.
 	content, err := ioutil.ReadFile(filepath.Clean(location[len(fileSchemeName)+1:]))
 	if err != nil {
-		return Retrieved{}, fmt.Errorf("unable to read the file %v: %w", location, err)
+		return config.Retrieved{}, fmt.Errorf("unable to read the file %v: %w", location, err)
 	}
 
 	var data map[string]interface{}
 	if err = yaml.Unmarshal(content, &data); err != nil {
-		return Retrieved{}, fmt.Errorf("unable to parse yaml: %w", err)
+		return config.Retrieved{}, fmt.Errorf("unable to parse yaml: %w", err)
 	}
 
-	return Retrieved{Map: config.NewMapFromStringMap(data)}, nil
+	return config.Retrieved{Map: config.NewMapFromStringMap(data)}, nil
 }
 
 func (*fileMapProvider) Shutdown(context.Context) error {

config/configmapprovider/file_test.go → config/filemapprovider/file_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package configmapprovider
+package filemapprovider
 
 import (
 	"context"
@@ -28,40 +28,40 @@ import (
 
 const fileSchemePrefix = fileSchemeName + ":"
 
-func TestFile_EmptyName(t *testing.T) {
-	fp := NewFile()
+func TestEmptyName(t *testing.T) {
+	fp := New()
 	_, err := fp.Retrieve(context.Background(), "", nil)
 	require.Error(t, err)
 	require.NoError(t, fp.Shutdown(context.Background()))
 }
 
-func TestFile_UnsupportedScheme(t *testing.T) {
-	fp := NewFile()
-	_, err := fp.Retrieve(context.Background(), "http://", nil)
+func TestUnsupportedScheme(t *testing.T) {
+	fp := New()
+	_, err := fp.Retrieve(context.Background(), "https://", nil)
 	assert.Error(t, err)
 	assert.NoError(t, fp.Shutdown(context.Background()))
 }
 
-func TestFile_NonExistent(t *testing.T) {
-	fp := NewFile()
+func TestNonExistent(t *testing.T) {
+	fp := New()
 	_, err := fp.Retrieve(context.Background(), fileSchemePrefix+filepath.Join("testdata", "non-existent.yaml"), nil)
 	assert.Error(t, err)
 	_, err = fp.Retrieve(context.Background(), fileSchemePrefix+absolutePath(t, filepath.Join("testdata", "non-existent.yaml")), nil)
 	assert.Error(t, err)
 	require.NoError(t, fp.Shutdown(context.Background()))
 }
 
-func TestFile_InvalidYaml(t *testing.T) {
-	fp := NewFile()
+func TestInvalidYaml(t *testing.T) {
+	fp := New()
 	_, err := fp.Retrieve(context.Background(), fileSchemePrefix+filepath.Join("testdata", "invalid-yaml.yaml"), nil)
 	assert.Error(t, err)
 	_, err = fp.Retrieve(context.Background(), fileSchemePrefix+absolutePath(t, filepath.Join("testdata", "invalid-yaml.yaml")), nil)
 	assert.Error(t, err)
 	require.NoError(t, fp.Shutdown(context.Background()))
 }
 
-func TestFile_RelativePath(t *testing.T) {
-	fp := NewFile()
+func TestRelativePath(t *testing.T) {
+	fp := New()
 	ret, err := fp.Retrieve(context.Background(), fileSchemePrefix+filepath.Join("testdata", "default-config.yaml"), nil)
 	require.NoError(t, err)
 	expectedMap := config.NewMapFromStringMap(map[string]interface{}{
@@ -72,8 +72,8 @@ func TestFile_RelativePath(t *testing.T) {
 	assert.NoError(t, fp.Shutdown(context.Background()))
 }
 
-func TestFile_AbsolutePath(t *testing.T) {
-	fp := NewFile()
+func TestAbsolutePath(t *testing.T) {
+	fp := New()
 	ret, err := fp.Retrieve(context.Background(), fileSchemePrefix+absolutePath(t, filepath.Join("testdata", "default-config.yaml")), nil)
 	require.NoError(t, err)
 	expectedMap := config.NewMapFromStringMap(map[string]interface{}{

config/filemapprovider/testdata/default-config.yaml

@@ -0,0 +1,5 @@
+processors:
+  batch:
+exporters:
+  otlp:
+    endpoint: "localhost:4317"