package consul import ( "fmt" "strings" "time" "github.com/armon/go-metrics" "github.com/hashicorp/consul/acl" "github.com/hashicorp/consul/agent/consul/state" "github.com/hashicorp/consul/agent/structs" "github.com/hashicorp/consul/api" "github.com/hashicorp/go-hclog" "github.com/hashicorp/go-memdb" ) // KVS endpoint is used to manipulate the Key-Value store type KVS struct { srv *Server logger hclog.Logger } // preApply does all the verification of a KVS update that is performed BEFORE // we submit as a Raft log entry. This includes enforcing the lock delay which // must only be done on the leader. func kvsPreApply(logger hclog.Logger, srv *Server, authz acl.Authorizer, op api.KVOp, dirEnt *structs.DirEntry) (bool, error) { // Verify the entry. if dirEnt.Key == "" && op != api.KVDeleteTree { return false, fmt.Errorf("Must provide key") } // Apply the ACL policy if any. if authz != nil { switch op { case api.KVDeleteTree: var authzContext acl.AuthorizerContext dirEnt.FillAuthzContext(&authzContext) if authz.KeyWritePrefix(dirEnt.Key, &authzContext) != acl.Allow { return false, acl.ErrPermissionDenied } case api.KVGet, api.KVGetTree: // Filtering for GETs is done on the output side. case api.KVCheckSession, api.KVCheckIndex: // These could reveal information based on the outcome // of the transaction, and they operate on individual // keys so we check them here. var authzContext acl.AuthorizerContext dirEnt.FillAuthzContext(&authzContext) if authz.KeyRead(dirEnt.Key, &authzContext) != acl.Allow { return false, acl.ErrPermissionDenied } default: var authzContext acl.AuthorizerContext dirEnt.FillAuthzContext(&authzContext) if authz.KeyWrite(dirEnt.Key, &authzContext) != acl.Allow { return false, acl.ErrPermissionDenied } } } // If this is a lock, we must check for a lock-delay. Since lock-delay // is based on wall-time, each peer would expire the lock-delay at a slightly // different time. This means the enforcement of lock-delay cannot be done // after the raft log is committed as it would lead to inconsistent FSMs. // Instead, the lock-delay must be enforced before commit. This means that // only the wall-time of the leader node is used, preventing any inconsistencies. if op == api.KVLock { state := srv.fsm.State() expires := state.KVSLockDelay(dirEnt.Key, &dirEnt.EnterpriseMeta) if expires.After(time.Now()) { logger.Warn("Rejecting lock of key due to lock-delay", "key", dirEnt.Key, "expire_time", expires.String(), ) return false, nil } } return true, nil } // Apply is used to apply a KVS update request to the data store. func (k *KVS) Apply(args *structs.KVSRequest, reply *bool) error { if done, err := k.srv.ForwardRPC("KVS.Apply", args, args, reply); done { return err } defer metrics.MeasureSince([]string{"kvs", "apply"}, time.Now()) // Perform the pre-apply checks. authz, err := k.srv.ResolveTokenAndDefaultMeta(args.Token, &args.DirEnt.EnterpriseMeta, nil) if err != nil { return err } if err := k.srv.validateEnterpriseRequest(&args.DirEnt.EnterpriseMeta, true); err != nil { return err } ok, err := kvsPreApply(k.logger, k.srv, authz, args.Op, &args.DirEnt) if err != nil { return err } if !ok { *reply = false return nil } // Apply the update. resp, err := k.srv.raftApply(structs.KVSRequestType, args) if err != nil { k.logger.Error("Raft apply failed", "error", err) return err } if respErr, ok := resp.(error); ok { return respErr } // Check if the return type is a bool. if respBool, ok := resp.(bool); ok { *reply = respBool } return nil } // Get is used to lookup a single key. func (k *KVS) Get(args *structs.KeyRequest, reply *structs.IndexedDirEntries) error { if done, err := k.srv.ForwardRPC("KVS.Get", args, args, reply); done { return err } var authzContext acl.AuthorizerContext authz, err := k.srv.ResolveTokenAndDefaultMeta(args.Token, &args.EnterpriseMeta, &authzContext) if err != nil { return err } if err := k.srv.validateEnterpriseRequest(&args.EnterpriseMeta, false); err != nil { return err } return k.srv.blockingQuery( &args.QueryOptions, &reply.QueryMeta, func(ws memdb.WatchSet, state *state.Store) error { index, ent, err := state.KVSGet(ws, args.Key, &args.EnterpriseMeta) if err != nil { return err } if authz != nil && authz.KeyRead(args.Key, &authzContext) != acl.Allow { return acl.ErrPermissionDenied } if ent == nil { // Must provide non-zero index to prevent blocking // Index 1 is impossible anyways (due to Raft internals) if index == 0 { reply.Index = 1 } else { reply.Index = index } reply.Entries = nil } else { reply.Index = ent.ModifyIndex reply.Entries = structs.DirEntries{ent} } return nil }) } // List is used to list all keys with a given prefix. func (k *KVS) List(args *structs.KeyRequest, reply *structs.IndexedDirEntries) error { if done, err := k.srv.ForwardRPC("KVS.List", args, args, reply); done { return err } var authzContext acl.AuthorizerContext authz, err := k.srv.ResolveTokenAndDefaultMeta(args.Token, &args.EnterpriseMeta, &authzContext) if err != nil { return err } if err := k.srv.validateEnterpriseRequest(&args.EnterpriseMeta, false); err != nil { return err } if authz != nil && k.srv.config.ACLEnableKeyListPolicy && authz.KeyList(args.Key, &authzContext) != acl.Allow { return acl.ErrPermissionDenied } return k.srv.blockingQuery( &args.QueryOptions, &reply.QueryMeta, func(ws memdb.WatchSet, state *state.Store) error { index, ent, err := state.KVSList(ws, args.Key, &args.EnterpriseMeta) if err != nil { return err } if authz != nil { ent = FilterDirEnt(authz, ent) } if len(ent) == 0 { // Must provide non-zero index to prevent blocking // Index 1 is impossible anyways (due to Raft internals) if index == 0 { reply.Index = 1 } else { reply.Index = index } reply.Entries = nil } else { reply.Index = index reply.Entries = ent } return nil }) } // ListKeys is used to list all keys with a given prefix to a separator. // An optional separator may be specified, which can be used to slice off a part // of the response so that only a subset of the prefix is returned. In this // mode, the keys which are omitted are still counted in the returned index. func (k *KVS) ListKeys(args *structs.KeyListRequest, reply *structs.IndexedKeyList) error { if done, err := k.srv.ForwardRPC("KVS.ListKeys", args, args, reply); done { return err } var authzContext acl.AuthorizerContext authz, err := k.srv.ResolveTokenAndDefaultMeta(args.Token, &args.EnterpriseMeta, &authzContext) if err != nil { return err } if err := k.srv.validateEnterpriseRequest(&args.EnterpriseMeta, false); err != nil { return err } if authz != nil && k.srv.config.ACLEnableKeyListPolicy && authz.KeyList(args.Prefix, &authzContext) != acl.Allow { return acl.ErrPermissionDenied } return k.srv.blockingQuery( &args.QueryOptions, &reply.QueryMeta, func(ws memdb.WatchSet, state *state.Store) error { index, entries, err := state.KVSList(ws, args.Prefix, &args.EnterpriseMeta) if err != nil { return err } // Must provide non-zero index to prevent blocking // Index 1 is impossible anyways (due to Raft internals) if index == 0 { reply.Index = 1 } else { reply.Index = index } if authz != nil { entries = FilterDirEnt(authz, entries) } // Collect the keys from the filtered entries prefixLen := len(args.Prefix) sepLen := len(args.Seperator) var keys []string seen := make(map[string]bool) for _, e := range entries { // Always accumulate if no separator provided if sepLen == 0 { keys = append(keys, e.Key) continue } // Parse and de-duplicate the returned keys based on the // key separator, if provided. after := e.Key[prefixLen:] sepIdx := strings.Index(after, args.Seperator) if sepIdx > -1 { key := e.Key[:prefixLen+sepIdx+sepLen] if ok := seen[key]; !ok { keys = append(keys, key) seen[key] = true } } else { keys = append(keys, e.Key) } } reply.Keys = keys return nil }) }