hanahmily commented on code in PR #928: URL: https://github.com/apache/skywalking-banyandb/pull/928#discussion_r2674782607
########## banyand/metadata/discovery/file/file.go: ########## @@ -0,0 +1,375 @@ +// Licensed to Apache Software Foundation (ASF) under one or more contributor +// license agreements. See the NOTICE file distributed with +// this work for additional information regarding copyright +// ownership. Apache Software Foundation (ASF) licenses this file to you under +// the Apache License, Version 2.0 (the "License"); you may +// not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +// Package file implements file-based node discovery for distributed metadata management. +package file + +import ( + "context" + "errors" + "fmt" + "os" + "sync" + "time" + + "gopkg.in/yaml.v3" + + databasev1 "github.com/apache/skywalking-banyandb/api/proto/banyandb/database/v1" + "github.com/apache/skywalking-banyandb/banyand/metadata/schema" + "github.com/apache/skywalking-banyandb/banyand/observability" + "github.com/apache/skywalking-banyandb/pkg/grpchelper" + "github.com/apache/skywalking-banyandb/pkg/logger" + "github.com/apache/skywalking-banyandb/pkg/run" +) + +// Service implements file-based node discovery. +type Service struct { + nodeCache map[string]*databasev1.Node + closer *run.Closer + log *logger.Logger + metrics *metrics + handlers map[string]schema.EventHandler + filePath string + grpcTimeout time.Duration + fetchInterval time.Duration + cacheMutex sync.RWMutex + handlersMutex sync.RWMutex +} + +// Config holds configuration for file discovery service. +type Config struct { + FilePath string + GRPCTimeout time.Duration + FetchInterval time.Duration +} + +// NodeFileConfig represents the YAML configuration file structure. +type NodeFileConfig struct { + Nodes []NodeConfig `yaml:"nodes"` +} + +// NodeConfig represents a single node configuration. +type NodeConfig struct { + Name string `yaml:"name"` + Address string `yaml:"grpc_address"` + CACertPath string `yaml:"ca_cert_path"` + TLSEnabled bool `yaml:"tls_enabled"` +} + +// NewService creates a new file discovery service. +func NewService(cfg Config) (*Service, error) { + if cfg.FilePath == "" { + return nil, errors.New("file path cannot be empty") + } + + // validate file exists and is readable + if _, err := os.Stat(cfg.FilePath); err != nil { + return nil, fmt.Errorf("failed to access file path %s: %w", cfg.FilePath, err) + } + + svc := &Service{ + filePath: cfg.FilePath, + nodeCache: make(map[string]*databasev1.Node), + handlers: make(map[string]schema.EventHandler), + closer: run.NewCloser(1), + log: logger.GetLogger("metadata-discovery-file"), + grpcTimeout: cfg.GRPCTimeout, + fetchInterval: cfg.FetchInterval, + } + + return svc, nil +} + +// Start begins the file discovery background process. +func (s *Service) Start(ctx context.Context) error { + s.log.Debug().Str("file_path", s.filePath).Msg("Starting file-based node discovery service") + + // initial load + if err := s.loadAndParseFile(ctx); err != nil { + return fmt.Errorf("failed to load initial configuration: %w", err) + } + + // start periodic fetch loop + go s.periodicFetch(ctx) + + return nil +} + +func (s *Service) loadAndParseFile(ctx context.Context) error { + startTime := time.Now() + var parseErr error + defer func() { + if s.metrics != nil { + duration := time.Since(startTime) + s.metrics.fileLoadCount.Inc(1) + s.metrics.fileLoadDuration.Observe(duration.Seconds()) + if parseErr != nil { + s.metrics.fileLoadFailedCount.Inc(1) + } + } + }() + + data, err := os.ReadFile(s.filePath) + if err != nil { + parseErr = fmt.Errorf("failed to read file: %w", err) + return parseErr + } + + var cfg NodeFileConfig + if err := yaml.Unmarshal(data, &cfg); err != nil { + parseErr = fmt.Errorf("failed to parse YAML: %w", err) + return parseErr + } + + // validate required fields + for idx, node := range cfg.Nodes { + if node.Address == "" { + parseErr = fmt.Errorf("node %s at index %d is missing required field: grpc_address", node.Name, idx) + return parseErr + } + if node.TLSEnabled && node.CACertPath == "" { + parseErr = fmt.Errorf("node %s at index %d has TLS enabled but missing ca_cert_path", node.Name, idx) + return parseErr + } + } + + // update cache + s.updateNodeCache(ctx, cfg.Nodes) + + s.log.Debug().Int("node_count", len(cfg.Nodes)).Msg("Successfully loaded configuration file") + return nil +} + +func (s *Service) fetchNodeMetadata(ctx context.Context, nodeConfig NodeConfig) (*databasev1.Node, error) { + ctxTimeout, cancel := context.WithTimeout(ctx, s.grpcTimeout) + defer cancel() + + // prepare TLS options + dialOpts, err := grpchelper.SecureOptions(nil, nodeConfig.TLSEnabled, false, nodeConfig.CACertPath) + if err != nil { + return nil, fmt.Errorf("failed to load TLS config for node %s: %w", nodeConfig.Name, err) + } + + // connect to node + // nolint:contextcheck + conn, connErr := grpchelper.Conn(nodeConfig.Address, s.grpcTimeout, dialOpts...) + if connErr != nil { + return nil, fmt.Errorf("failed to connect to %s: %w", nodeConfig.Address, connErr) + } + defer conn.Close() + + // query metadata of the node + client := databasev1.NewNodeQueryServiceClient(conn) + resp, callErr := client.GetCurrentNode(ctxTimeout, &databasev1.GetCurrentNodeRequest{}) + if callErr != nil { + return nil, fmt.Errorf("failed to get current node from %s: %w", nodeConfig.Address, callErr) + } + + return resp.GetNode(), nil +} + +func (s *Service) updateNodeCache(ctx context.Context, newNodes []NodeConfig) { + for _, n := range newNodes { + s.cacheMutex.RLock() + _, exists := s.nodeCache[n.Address] + s.cacheMutex.RUnlock() + + if !exists { + // fetch node metadata from gRPC + node, fetchErr := s.fetchNodeMetadata(ctx, n) + if fetchErr != nil { + s.log.Warn(). + Err(fetchErr). + Str("node", n.Name). + Str("address", n.Address). + Msg("Failed to fetch node metadata, will skip") + continue + } + + var ( + added bool + metadata schema.Metadata + ) + + s.cacheMutex.Lock() + if _, alreadyAdded := s.nodeCache[n.Address]; !alreadyAdded { + s.nodeCache[n.Address] = node + added = true + metadata = schema.Metadata{ + TypeMeta: schema.TypeMeta{ + Kind: schema.KindNode, + Name: node.GetMetadata().GetName(), + }, + Spec: node, + } + } + s.cacheMutex.Unlock() + + if added { + // notify handlers after releasing lock + s.notifyHandlers(metadata, true) + + s.log.Debug(). + Str("address", n.Address). + Str("name", node.GetMetadata().GetName()). + Msg("New node discovered and added to cache") + } + } + } + + // collect nodes to delete first + allAddr := make(map[string]bool) + for _, n := range newNodes { + allAddr[n.Address] = true + } + s.cacheMutex.Lock() + nodesToDelete := make(map[string]*databasev1.Node) + for addr, node := range s.nodeCache { + if !allAddr[addr] { + nodesToDelete[addr] = node + } + } + + // delete from cache while still holding lock + for addr, node := range nodesToDelete { + delete(s.nodeCache, addr) + s.log.Debug(). + Str("address", addr). + Str("name", node.GetMetadata().GetName()). + Msg("Node removed from cache (no longer in file)") + } + cacheSize := len(s.nodeCache) + s.cacheMutex.Unlock() + + // Notify handlers after releasing lock + for _, node := range nodesToDelete { + s.notifyHandlers(schema.Metadata{ + TypeMeta: schema.TypeMeta{ + Kind: schema.KindNode, + Name: node.GetMetadata().GetName(), + }, + Spec: node, + }, false) + } + // update metrics + if s.metrics != nil { + s.metrics.totalNodesCount.Set(float64(cacheSize)) + } +} + +func (s *Service) notifyHandlers(metadata schema.Metadata, isAddOrUpdate bool) { + s.handlersMutex.RLock() + defer s.handlersMutex.RUnlock() + + for _, handler := range s.handlers { + if isAddOrUpdate { + handler.OnAddOrUpdate(metadata) + } else { + handler.OnDelete(metadata) + } + } +} + +// RegisterHandler registers an event handler for node changes. +func (s *Service) RegisterHandler(name string, handler schema.EventHandler) { + s.handlersMutex.Lock() + defer s.handlersMutex.Unlock() + + s.handlers[name] = handler + s.log.Debug().Str("handler", name).Msg("Registered file node discovery handler") +} + +// SetMetrics sets the OMR metrics. +func (s *Service) SetMetrics(factory observability.Factory) { + s.metrics = newMetrics(factory) +} + +// Close stops the file discovery service. +func (s *Service) Close() error { + s.closer.Done() + s.closer.CloseThenWait() + + return nil +} + +// ListNode lists all existing nodes from cache. +func (s *Service) ListNode(_ context.Context, role databasev1.Role) ([]*databasev1.Node, error) { + s.cacheMutex.RLock() + defer s.cacheMutex.RUnlock() + + var result []*databasev1.Node + for _, node := range s.nodeCache { + // filter by role if specified + if role != databasev1.Role_ROLE_UNSPECIFIED { + hasRole := false + for _, nodeRole := range node.GetRoles() { + if nodeRole == role { + hasRole = true + break + } + } + if !hasRole { + continue + } + } + result = append(result, node) + } + + return result, nil +} + +// GetNode gets a specific node from cache. +func (s *Service) GetNode(_ context.Context, nodeName string) (*databasev1.Node, error) { + s.cacheMutex.RLock() + defer s.cacheMutex.RUnlock() + + for _, node := range s.nodeCache { + if node.GetMetadata() != nil && node.GetMetadata().GetName() == nodeName { + return node, nil + } + } + + return nil, fmt.Errorf("node %s not found", nodeName) +} + +// RegisterNode is not supported in file discovery mode. +func (s *Service) RegisterNode(_ context.Context, _ *databasev1.Node, _ bool) error { + return errors.New("manual node registration not supported in file discovery mode") +} + +// UpdateNode is not supported in file discovery mode. +func (s *Service) UpdateNode(_ context.Context, _ *databasev1.Node) error { + return errors.New("manual node update not supported in file discovery mode") +} + +func (s *Service) periodicFetch(ctx context.Context) { Review Comment: Could you use "github.com/fsnotify/fsnotify" to check the change of this file? We have examples to implement authN and TLS file reloading. ########## banyand/metadata/discovery/file/file.go: ########## @@ -0,0 +1,375 @@ +// Licensed to Apache Software Foundation (ASF) under one or more contributor +// license agreements. See the NOTICE file distributed with +// this work for additional information regarding copyright +// ownership. Apache Software Foundation (ASF) licenses this file to you under +// the Apache License, Version 2.0 (the "License"); you may +// not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +// Package file implements file-based node discovery for distributed metadata management. +package file + +import ( + "context" + "errors" + "fmt" + "os" + "sync" + "time" + + "gopkg.in/yaml.v3" + + databasev1 "github.com/apache/skywalking-banyandb/api/proto/banyandb/database/v1" + "github.com/apache/skywalking-banyandb/banyand/metadata/schema" + "github.com/apache/skywalking-banyandb/banyand/observability" + "github.com/apache/skywalking-banyandb/pkg/grpchelper" + "github.com/apache/skywalking-banyandb/pkg/logger" + "github.com/apache/skywalking-banyandb/pkg/run" +) + +// Service implements file-based node discovery. +type Service struct { + nodeCache map[string]*databasev1.Node + closer *run.Closer + log *logger.Logger + metrics *metrics + handlers map[string]schema.EventHandler + filePath string + grpcTimeout time.Duration + fetchInterval time.Duration + cacheMutex sync.RWMutex + handlersMutex sync.RWMutex +} + +// Config holds configuration for file discovery service. +type Config struct { + FilePath string + GRPCTimeout time.Duration + FetchInterval time.Duration +} + +// NodeFileConfig represents the YAML configuration file structure. +type NodeFileConfig struct { + Nodes []NodeConfig `yaml:"nodes"` +} + +// NodeConfig represents a single node configuration. +type NodeConfig struct { + Name string `yaml:"name"` + Address string `yaml:"grpc_address"` + CACertPath string `yaml:"ca_cert_path"` + TLSEnabled bool `yaml:"tls_enabled"` +} + +// NewService creates a new file discovery service. +func NewService(cfg Config) (*Service, error) { + if cfg.FilePath == "" { + return nil, errors.New("file path cannot be empty") + } + + // validate file exists and is readable + if _, err := os.Stat(cfg.FilePath); err != nil { + return nil, fmt.Errorf("failed to access file path %s: %w", cfg.FilePath, err) + } + + svc := &Service{ + filePath: cfg.FilePath, + nodeCache: make(map[string]*databasev1.Node), + handlers: make(map[string]schema.EventHandler), + closer: run.NewCloser(1), + log: logger.GetLogger("metadata-discovery-file"), + grpcTimeout: cfg.GRPCTimeout, + fetchInterval: cfg.FetchInterval, + } + + return svc, nil +} + +// Start begins the file discovery background process. +func (s *Service) Start(ctx context.Context) error { + s.log.Debug().Str("file_path", s.filePath).Msg("Starting file-based node discovery service") + + // initial load + if err := s.loadAndParseFile(ctx); err != nil { + return fmt.Errorf("failed to load initial configuration: %w", err) + } + + // start periodic fetch loop + go s.periodicFetch(ctx) + + return nil +} + +func (s *Service) loadAndParseFile(ctx context.Context) error { + startTime := time.Now() + var parseErr error + defer func() { + if s.metrics != nil { + duration := time.Since(startTime) + s.metrics.fileLoadCount.Inc(1) + s.metrics.fileLoadDuration.Observe(duration.Seconds()) + if parseErr != nil { + s.metrics.fileLoadFailedCount.Inc(1) + } + } + }() + + data, err := os.ReadFile(s.filePath) + if err != nil { + parseErr = fmt.Errorf("failed to read file: %w", err) + return parseErr + } + + var cfg NodeFileConfig + if err := yaml.Unmarshal(data, &cfg); err != nil { + parseErr = fmt.Errorf("failed to parse YAML: %w", err) + return parseErr + } + + // validate required fields + for idx, node := range cfg.Nodes { + if node.Address == "" { + parseErr = fmt.Errorf("node %s at index %d is missing required field: grpc_address", node.Name, idx) + return parseErr + } + if node.TLSEnabled && node.CACertPath == "" { + parseErr = fmt.Errorf("node %s at index %d has TLS enabled but missing ca_cert_path", node.Name, idx) + return parseErr + } + } + + // update cache + s.updateNodeCache(ctx, cfg.Nodes) + + s.log.Debug().Int("node_count", len(cfg.Nodes)).Msg("Successfully loaded configuration file") + return nil +} + +func (s *Service) fetchNodeMetadata(ctx context.Context, nodeConfig NodeConfig) (*databasev1.Node, error) { + ctxTimeout, cancel := context.WithTimeout(ctx, s.grpcTimeout) + defer cancel() + + // prepare TLS options + dialOpts, err := grpchelper.SecureOptions(nil, nodeConfig.TLSEnabled, false, nodeConfig.CACertPath) + if err != nil { + return nil, fmt.Errorf("failed to load TLS config for node %s: %w", nodeConfig.Name, err) + } + + // connect to node + // nolint:contextcheck + conn, connErr := grpchelper.Conn(nodeConfig.Address, s.grpcTimeout, dialOpts...) + if connErr != nil { + return nil, fmt.Errorf("failed to connect to %s: %w", nodeConfig.Address, connErr) + } + defer conn.Close() + + // query metadata of the node + client := databasev1.NewNodeQueryServiceClient(conn) + resp, callErr := client.GetCurrentNode(ctxTimeout, &databasev1.GetCurrentNodeRequest{}) + if callErr != nil { + return nil, fmt.Errorf("failed to get current node from %s: %w", nodeConfig.Address, callErr) + } + + return resp.GetNode(), nil +} + +func (s *Service) updateNodeCache(ctx context.Context, newNodes []NodeConfig) { Review Comment: This method seems to be the same as the one used in DNS discovery. Could you extract the same logic to reuse in those cases? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
