refactor: move remote code to separate file

Signed-off-by: Mark Sagi-Kazar <mark.sagikazar@gmail.com>

Author: sagikazarmark

remote.go

@@ -0,0 +1,255 @@
+package viper
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"reflect"
+)
+
+// SupportedRemoteProviders are universally supported remote providers.
+var SupportedRemoteProviders = []string{"etcd", "etcd3", "consul", "firestore", "nats"}
+
+func resetRemote() {
+	SupportedRemoteProviders = []string{"etcd", "etcd3", "consul", "firestore", "nats"}
+}
+
+type remoteConfigFactory interface {
+	Get(rp RemoteProvider) (io.Reader, error)
+	Watch(rp RemoteProvider) (io.Reader, error)
+	WatchChannel(rp RemoteProvider) (<-chan *RemoteResponse, chan bool)
+}
+
+type RemoteResponse struct {
+	Value []byte
+	Error error
+}
+
+// RemoteConfig is optional, see the remote package.
+var RemoteConfig remoteConfigFactory
+
+// UnsupportedRemoteProviderError denotes encountering an unsupported remote
+// provider. Currently only etcd and Consul are supported.
+type UnsupportedRemoteProviderError string
+
+// Error returns the formatted remote provider error.
+func (str UnsupportedRemoteProviderError) Error() string {
+	return fmt.Sprintf("Unsupported Remote Provider Type %q", string(str))
+}
+
+// RemoteConfigError denotes encountering an error while trying to
+// pull the configuration from the remote provider.
+type RemoteConfigError string
+
+// Error returns the formatted remote provider error.
+func (rce RemoteConfigError) Error() string {
+	return fmt.Sprintf("Remote Configurations Error: %s", string(rce))
+}
+
+type defaultRemoteProvider struct {
+	provider      string
+	endpoint      string
+	path          string
+	secretKeyring string
+}
+
+func (rp defaultRemoteProvider) Provider() string {
+	return rp.provider
+}
+
+func (rp defaultRemoteProvider) Endpoint() string {
+	return rp.endpoint
+}
+
+func (rp defaultRemoteProvider) Path() string {
+	return rp.path
+}
+
+func (rp defaultRemoteProvider) SecretKeyring() string {
+	return rp.secretKeyring
+}
+
+// RemoteProvider stores the configuration necessary
+// to connect to a remote key/value store.
+// Optional secretKeyring to unencrypt encrypted values
+// can be provided.
+type RemoteProvider interface {
+	Provider() string
+	Endpoint() string
+	Path() string
+	SecretKeyring() string
+}
+
+// AddRemoteProvider adds a remote configuration source.
+// Remote Providers are searched in the order they are added.
+// provider is a string value: "etcd", "etcd3", "consul", "firestore" or "nats" are currently supported.
+// endpoint is the url.  etcd requires http://ip:port, consul requires ip:port, nats requires nats://ip:port
+// path is the path in the k/v store to retrieve configuration
+// To retrieve a config file called myapp.json from /configs/myapp.json
+// you should set path to /configs and set config name (SetConfigName()) to
+// "myapp".
+func AddRemoteProvider(provider, endpoint, path string) error {
+	return v.AddRemoteProvider(provider, endpoint, path)
+}
+
+func (v *Viper) AddRemoteProvider(provider, endpoint, path string) error {
+	if !stringInSlice(provider, SupportedRemoteProviders) {
+		return UnsupportedRemoteProviderError(provider)
+	}
+	if provider != "" && endpoint != "" {
+		v.logger.Info("adding remote provider", "provider", provider, "endpoint", endpoint)
+
+		rp := &defaultRemoteProvider{
+			endpoint: endpoint,
+			provider: provider,
+			path:     path,
+		}
+		if !v.providerPathExists(rp) {
+			v.remoteProviders = append(v.remoteProviders, rp)
+		}
+	}
+	return nil
+}
+
+// AddSecureRemoteProvider adds a remote configuration source.
+// Secure Remote Providers are searched in the order they are added.
+// provider is a string value: "etcd", "etcd3", "consul", "firestore" or "nats" are currently supported.
+// endpoint is the url.  etcd requires http://ip:port  consul requires ip:port
+// secretkeyring is the filepath to your openpgp secret keyring.  e.g. /etc/secrets/myring.gpg
+// path is the path in the k/v store to retrieve configuration
+// To retrieve a config file called myapp.json from /configs/myapp.json
+// you should set path to /configs and set config name (SetConfigName()) to
+// "myapp".
+// Secure Remote Providers are implemented with github.com/sagikazarmark/crypt.
+func AddSecureRemoteProvider(provider, endpoint, path, secretkeyring string) error {
+	return v.AddSecureRemoteProvider(provider, endpoint, path, secretkeyring)
+}
+
+func (v *Viper) AddSecureRemoteProvider(provider, endpoint, path, secretkeyring string) error {
+	if !stringInSlice(provider, SupportedRemoteProviders) {
+		return UnsupportedRemoteProviderError(provider)
+	}
+	if provider != "" && endpoint != "" {
+		v.logger.Info("adding remote provider", "provider", provider, "endpoint", endpoint)
+
+		rp := &defaultRemoteProvider{
+			endpoint:      endpoint,
+			provider:      provider,
+			path:          path,
+			secretKeyring: secretkeyring,
+		}
+		if !v.providerPathExists(rp) {
+			v.remoteProviders = append(v.remoteProviders, rp)
+		}
+	}
+	return nil
+}
+
+func (v *Viper) providerPathExists(p *defaultRemoteProvider) bool {
+	for _, y := range v.remoteProviders {
+		if reflect.DeepEqual(y, p) {
+			return true
+		}
+	}
+	return false
+}
+
+// ReadRemoteConfig attempts to get configuration from a remote source
+// and read it in the remote configuration registry.
+func ReadRemoteConfig() error { return v.ReadRemoteConfig() }
+
+func (v *Viper) ReadRemoteConfig() error {
+	return v.getKeyValueConfig()
+}
+
+func WatchRemoteConfig() error { return v.WatchRemoteConfig() }
+func (v *Viper) WatchRemoteConfig() error {
+	return v.watchKeyValueConfig()
+}
+
+func (v *Viper) WatchRemoteConfigOnChannel() error {
+	return v.watchKeyValueConfigOnChannel()
+}
+
+// Retrieve the first found remote configuration.
+func (v *Viper) getKeyValueConfig() error {
+	if RemoteConfig == nil {
+		return RemoteConfigError("Enable the remote features by doing a blank import of the viper/remote package: '_ github.com/spf13/viper/remote'")
+	}
+
+	if len(v.remoteProviders) == 0 {
+		return RemoteConfigError("No Remote Providers")
+	}
+
+	for _, rp := range v.remoteProviders {
+		val, err := v.getRemoteConfig(rp)
+		if err != nil {
+			v.logger.Error(fmt.Errorf("get remote config: %w", err).Error())
+
+			continue
+		}
+
+		v.kvstore = val
+
+		return nil
+	}
+	return RemoteConfigError("No Files Found")
+}
+
+func (v *Viper) getRemoteConfig(provider RemoteProvider) (map[string]any, error) {
+	reader, err := RemoteConfig.Get(provider)
+	if err != nil {
+		return nil, err
+	}
+	err = v.unmarshalReader(reader, v.kvstore)
+	return v.kvstore, err
+}
+
+// Retrieve the first found remote configuration.
+func (v *Viper) watchKeyValueConfigOnChannel() error {
+	if len(v.remoteProviders) == 0 {
+		return RemoteConfigError("No Remote Providers")
+	}
+
+	for _, rp := range v.remoteProviders {
+		respc, _ := RemoteConfig.WatchChannel(rp)
+		// Todo: Add quit channel
+		go func(rc <-chan *RemoteResponse) {
+			for {
+				b := <-rc
+				reader := bytes.NewReader(b.Value)
+				v.unmarshalReader(reader, v.kvstore)
+			}
+		}(respc)
+		return nil
+	}
+	return RemoteConfigError("No Files Found")
+}
+
+// Retrieve the first found remote configuration.
+func (v *Viper) watchKeyValueConfig() error {
+	if len(v.remoteProviders) == 0 {
+		return RemoteConfigError("No Remote Providers")
+	}
+
+	for _, rp := range v.remoteProviders {
+		val, err := v.watchRemoteConfig(rp)
+		if err != nil {
+			v.logger.Error(fmt.Errorf("watch remote config: %w", err).Error())
+
+			continue
+		}
+		v.kvstore = val
+		return nil
+	}
+	return RemoteConfigError("No Files Found")
+}
+
+func (v *Viper) watchRemoteConfig(provider RemoteProvider) (map[string]any, error) {
+	reader, err := RemoteConfig.Watch(provider)
+	if err != nil {
+		return nil, err
+	}
+	err = v.unmarshalReader(reader, v.kvstore)
+	return v.kvstore, err
+}