// Copyright 2019 Sorint.lab // // Licensed 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 etcd import ( "context" "crypto/tls" "net/url" "strconv" "strings" "time" "github.com/sorintlab/agola/internal/util" "github.com/pkg/errors" "go.etcd.io/etcd/clientv3" etcdclientv3 "go.etcd.io/etcd/clientv3" "go.etcd.io/etcd/clientv3/namespace" "go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes" "go.uber.org/zap" ) var ( // ErrKeyNotFound is thrown when the key is not found in the store during a Get operation ErrKeyNotFound = errors.New("key not found") ErrKeyModified = errors.New("unable to complete atomic operation, key modified") ) const ( defaultEndpoints = "http://127.0.0.1:2379" compactKey = "compactkey" defaultCompactionInterval = 10 * time.Minute ) type WriteOptions struct { TTL time.Duration } type Config struct { Logger *zap.Logger Endpoints string Prefix string CertFile string KeyFile string CAFile string SkipTLSVerify bool CompactionInterval time.Duration } func FromEtcdError(err error) error { switch err { case rpctypes.ErrKeyNotFound: return ErrKeyNotFound } return err } type Store struct { log *zap.SugaredLogger c *etcdclientv3.Client } func New(cfg Config) (*Store, error) { prefix := cfg.Prefix if prefix != "" && !strings.HasSuffix(prefix, "/") { prefix += "/" } endpointsStr := cfg.Endpoints if endpointsStr == "" { endpointsStr = defaultEndpoints } endpoints := strings.Split(endpointsStr, ",") // check that all the endpoints have the same scheme var scheme string for _, e := range endpoints { u, err := url.Parse(e) if err != nil { return nil, errors.Wrapf(err, "cannot parse endpoint %q", e) } if scheme == "" { scheme = u.Scheme } if scheme != u.Scheme { return nil, errors.Errorf("all the endpoints must have the same scheme") } } var tlsConfig *tls.Config if scheme != "http" && scheme != "https" { return nil, errors.Errorf("endpoints scheme must be http or https") } if scheme == "https" { var err error tlsConfig, err = util.NewTLSConfig(cfg.CertFile, cfg.KeyFile, cfg.CAFile, cfg.SkipTLSVerify) if err != nil { return nil, errors.Wrapf(err, "cannot create tls config") } } config := etcdclientv3.Config{ Endpoints: endpoints, TLS: tlsConfig, } c, err := etcdclientv3.New(config) if err != nil { return nil, err } c.KV = namespace.NewKV(c.KV, prefix) c.Watcher = namespace.NewWatcher(c.Watcher, prefix) c.Lease = namespace.NewLease(c.Lease, prefix) s := &Store{ log: cfg.Logger.Sugar(), c: c, } compactionInterval := defaultCompactionInterval if cfg.CompactionInterval != 0 { compactionInterval = cfg.CompactionInterval } go s.compactor(context.TODO(), compactionInterval) return s, nil } func (s *Store) Client() *etcdclientv3.Client { return s.c } func (s *Store) Put(ctx context.Context, key string, value []byte, options *WriteOptions) (*etcdclientv3.PutResponse, error) { etcdv3Options := []etcdclientv3.OpOption{} if options != nil { if options.TTL > 0 { lease, err := s.c.Grant(ctx, int64(options.TTL.Seconds())) if err != nil { return nil, err } etcdv3Options = append(etcdv3Options, etcdclientv3.WithLease(lease.ID)) } } resp, err := s.c.Put(ctx, key, string(value), etcdv3Options...) return resp, FromEtcdError(err) } func (s *Store) Get(ctx context.Context, key string) (*etcdclientv3.GetResponse, error) { resp, err := s.c.Get(ctx, key) if err != nil { return resp, FromEtcdError(err) } if len(resp.Kvs) == 0 { return resp, ErrKeyNotFound } return resp, nil } func (s *Store) List(ctx context.Context, directory, start string, revision int64) (*etcdclientv3.GetResponse, error) { if !strings.HasSuffix(directory, "/") { directory += "/" } key := directory rangeEnd := clientv3.GetPrefixRangeEnd(key) if start != "" { key = start } opts := []etcdclientv3.OpOption{etcdclientv3.WithRange(rangeEnd)} if revision != 0 { opts = append(opts, etcdclientv3.WithRev(revision)) } resp, err := s.c.Get(ctx, key, opts...) return resp, FromEtcdError(err) } type ListPagedResp struct { Resp *clientv3.GetResponse HasMore bool Continuation *ListPagedContinuation } type ListPagedContinuation struct { Revision int64 LastKey string } func (s *Store) ListPaged(ctx context.Context, directory string, revision, limit int64, continuation *ListPagedContinuation) (*ListPagedResp, error) { if !strings.HasSuffix(directory, "/") { directory += "/" } key := directory rangeEnd := clientv3.GetPrefixRangeEnd(key) if continuation != nil { revision = continuation.Revision key = continuation.LastKey } opts := []etcdclientv3.OpOption{etcdclientv3.WithRange(rangeEnd), etcdclientv3.WithLimit(limit)} if revision != 0 { opts = append(opts, etcdclientv3.WithRev(revision)) } resp, err := s.c.Get(ctx, key, opts...) if err != nil { return nil, FromEtcdError(err) } lastKey := key if len(resp.Kvs) > 0 { lastKey = string(resp.Kvs[len(resp.Kvs)-1].Key) + "\x00" } return &ListPagedResp{ Resp: resp, HasMore: resp.More, Continuation: &ListPagedContinuation{ Revision: resp.Header.Revision, LastKey: lastKey, }, }, nil } func (s *Store) AtomicPut(ctx context.Context, key string, value []byte, prevRevision int64, options *WriteOptions) (*etcdclientv3.TxnResponse, error) { etcdv3Options := []etcdclientv3.OpOption{} if options != nil { if options.TTL > 0 { lease, err := s.c.Grant(ctx, int64(options.TTL)) if err != nil { return nil, err } etcdv3Options = append(etcdv3Options, etcdclientv3.WithLease(lease.ID)) } } var cmp etcdclientv3.Cmp if prevRevision != 0 { cmp = etcdclientv3.Compare(etcdclientv3.ModRevision(key), "=", int64(prevRevision)) } else { // key must not exist cmp = etcdclientv3.Compare(etcdclientv3.CreateRevision(key), "=", 0) } txn := s.c.Txn(ctx).If(cmp) txn = txn.Then(etcdclientv3.OpPut(key, string(value), etcdv3Options...)) tresp, err := txn.Commit() if err != nil { return tresp, FromEtcdError(err) } if !tresp.Succeeded { return tresp, ErrKeyModified } return tresp, nil } func (s *Store) Delete(ctx context.Context, key string) error { _, err := s.c.Delete(ctx, key) return err } func (s *Store) AtomicDelete(ctx context.Context, key string, revision int64) (*etcdclientv3.TxnResponse, error) { cmp := etcdclientv3.Compare(etcdclientv3.ModRevision(key), "=", revision) req := etcdclientv3.OpDelete(key) tresp, err := s.c.Txn(ctx).If(cmp).Then(req).Commit() if err != nil { return tresp, FromEtcdError(err) } if !tresp.Succeeded { return tresp, ErrKeyModified } return tresp, nil } func (s *Store) Watch(ctx context.Context, prefix string, revision int64) etcdclientv3.WatchChan { etcdv3Options := []etcdclientv3.OpOption{clientv3.WithPrefix()} if revision != 0 { etcdv3Options = append(etcdv3Options, etcdclientv3.WithRev(revision)) } return s.c.Watch(ctx, prefix, etcdv3Options...) } func (s *Store) Close() error { return s.c.Close() } func (s *Store) compactor(ctx context.Context, interval time.Duration) { var version int64 var rev int64 var err error for { select { case <-time.After(interval): case <-ctx.Done(): return } version, rev, err = s.compact(ctx, version, rev) if err != nil { continue } } } func (s *Store) compact(ctx context.Context, version, rev int64) (int64, int64, error) { resp, err := s.c.KV.Txn(ctx).If( clientv3.Compare(clientv3.Version(compactKey), "=", version), ).Then( clientv3.OpPut(compactKey, strconv.FormatInt(rev, 10)), ).Else( clientv3.OpGet(compactKey), ).Commit() if err != nil { return version, rev, err } curRev := resp.Header.Revision if !resp.Succeeded { curVersion := resp.Responses[0].GetResponseRange().Kvs[0].Version return curVersion, curRev, nil } curVersion := version + 1 if rev == 0 { return curVersion, curRev, nil } if _, err = s.c.Compact(ctx, rev); err != nil { s.log.Warnf("compact error: %v", err) return curVersion, curRev, err } s.log.Infof("compacted revision: %d", rev) return curVersion, curRev, nil }