package structs import ( "bytes" "fmt" "math/rand" "reflect" "regexp" "strings" "time" "github.com/hashicorp/consul/api" "github.com/hashicorp/consul/types" "github.com/hashicorp/go-msgpack/codec" "github.com/hashicorp/go-multierror" "github.com/hashicorp/serf/coordinate" ) type MessageType uint8 // RaftIndex is used to track the index used while creating // or modifying a given struct type. type RaftIndex struct { CreateIndex uint64 ModifyIndex uint64 } // These are serialized between Consul servers and stored in Consul snapshots, // so entries must only ever be added. const ( RegisterRequestType MessageType = 0 DeregisterRequestType = 1 KVSRequestType = 2 SessionRequestType = 3 ACLRequestType = 4 TombstoneRequestType = 5 CoordinateBatchUpdateType = 6 PreparedQueryRequestType = 7 TxnRequestType = 8 AutopilotRequestType = 9 AreaRequestType = 10 ACLBootstrapRequestType = 11 // FSM snapshots only. IntentionRequestType = 12 ConnectCARequestType = 13 ) const ( // IgnoreUnknownTypeFlag is set along with a MessageType // to indicate that the message type can be safely ignored // if it is not recognized. This is for future proofing, so // that new commands can be added in a way that won't cause // old servers to crash when the FSM attempts to process them. IgnoreUnknownTypeFlag MessageType = 128 // NodeMaint is the special key set by a node in maintenance mode. NodeMaint = "_node_maintenance" // ServiceMaintPrefix is the prefix for a service in maintenance mode. ServiceMaintPrefix = "_service_maintenance:" // The meta key prefix reserved for Consul's internal use metaKeyReservedPrefix = "consul-" // metaMaxKeyPairs is maximum number of metadata key pairs allowed to be registered metaMaxKeyPairs = 64 // metaKeyMaxLength is the maximum allowed length of a metadata key metaKeyMaxLength = 128 // metaValueMaxLength is the maximum allowed length of a metadata value metaValueMaxLength = 512 // MetaSegmentKey is the node metadata key used to store the node's network segment MetaSegmentKey = "consul-network-segment" // MaxLockDelay provides a maximum LockDelay value for // a session. Any value above this will not be respected. MaxLockDelay = 60 * time.Second ) // metaKeyFormat checks if a metadata key string is valid var metaKeyFormat = regexp.MustCompile(`^[a-zA-Z0-9_-]+$`).MatchString func ValidStatus(s string) bool { return s == api.HealthPassing || s == api.HealthWarning || s == api.HealthCritical } // RPCInfo is used to describe common information about query type RPCInfo interface { RequestDatacenter() string IsRead() bool AllowStaleRead() bool ACLToken() string } // QueryOptions is used to specify various flags for read queries type QueryOptions struct { // Token is the ACL token ID. If not provided, the 'anonymous' // token is assumed for backwards compatibility. Token string // If set, wait until query exceeds given index. Must be provided // with MaxQueryTime. MinQueryIndex uint64 // Provided with MinQueryIndex to wait for change. MaxQueryTime time.Duration // If set, any follower can service the request. Results // may be arbitrarily stale. AllowStale bool // If set, the leader must verify leadership prior to // servicing the request. Prevents a stale read. RequireConsistent bool // If set and AllowStale is true, will try first a stale // read, and then will perform a consistent read if stale // read is older than value MaxStaleDuration time.Duration } // IsRead is always true for QueryOption. func (q QueryOptions) IsRead() bool { return true } // ConsistencyLevel display the consistency required by a request func (q QueryOptions) ConsistencyLevel() string { if q.RequireConsistent { return "consistent" } else if q.AllowStale { return "stale" } else { return "leader" } } func (q QueryOptions) AllowStaleRead() bool { return q.AllowStale } func (q QueryOptions) ACLToken() string { return q.Token } type WriteRequest struct { // Token is the ACL token ID. If not provided, the 'anonymous' // token is assumed for backwards compatibility. Token string } // WriteRequest only applies to writes, always false func (w WriteRequest) IsRead() bool { return false } func (w WriteRequest) AllowStaleRead() bool { return false } func (w WriteRequest) ACLToken() string { return w.Token } // QueryMeta allows a query response to include potentially // useful metadata about a query type QueryMeta struct { // This is the index associated with the read Index uint64 // If AllowStale is used, this is time elapsed since // last contact between the follower and leader. This // can be used to gauge staleness. LastContact time.Duration // Used to indicate if there is a known leader node KnownLeader bool // Consistencylevel returns the consistency used to serve the query // Having `discovery_max_stale` on the agent can affect whether // the request was served by a leader. ConsistencyLevel string } // RegisterRequest is used for the Catalog.Register endpoint // to register a node as providing a service. If no service // is provided, the node is registered. type RegisterRequest struct { Datacenter string ID types.NodeID Node string Address string TaggedAddresses map[string]string NodeMeta map[string]string Service *NodeService Check *HealthCheck Checks HealthChecks // SkipNodeUpdate can be used when a register request is intended for // updating a service and/or checks, but doesn't want to overwrite any // node information if the node is already registered. If the node // doesn't exist, it will still be created, but if the node exists, any // node portion of this update will not apply. SkipNodeUpdate bool WriteRequest } func (r *RegisterRequest) RequestDatacenter() string { return r.Datacenter } // ChangesNode returns true if the given register request changes the given // node, which can be nil. This only looks for changes to the node record itself, // not any of the health checks. func (r *RegisterRequest) ChangesNode(node *Node) bool { // This means it's creating the node. if node == nil { return true } // If we've been asked to skip the node update, then say there are no // changes. if r.SkipNodeUpdate { return false } // Check if any of the node-level fields are being changed. if r.ID != node.ID || r.Node != node.Node || r.Address != node.Address || r.Datacenter != node.Datacenter || !reflect.DeepEqual(r.TaggedAddresses, node.TaggedAddresses) || !reflect.DeepEqual(r.NodeMeta, node.Meta) { return true } return false } // DeregisterRequest is used for the Catalog.Deregister endpoint // to deregister a node as providing a service. If no service is // provided the entire node is deregistered. type DeregisterRequest struct { Datacenter string Node string ServiceID string CheckID types.CheckID WriteRequest } func (r *DeregisterRequest) RequestDatacenter() string { return r.Datacenter } // QuerySource is used to pass along information about the source node // in queries so that we can adjust the response based on its network // coordinates. type QuerySource struct { Datacenter string Segment string Node string Ip string } // DCSpecificRequest is used to query about a specific DC type DCSpecificRequest struct { Datacenter string NodeMetaFilters map[string]string Source QuerySource QueryOptions } func (r *DCSpecificRequest) RequestDatacenter() string { return r.Datacenter } // ServiceSpecificRequest is used to query about a specific service type ServiceSpecificRequest struct { Datacenter string NodeMetaFilters map[string]string ServiceName string ServiceTag string ServiceAddress string TagFilter bool // Controls tag filtering Source QuerySource // Connect if true will only search for Connect-compatible services. Connect bool QueryOptions } func (r *ServiceSpecificRequest) RequestDatacenter() string { return r.Datacenter } // NodeSpecificRequest is used to request the information about a single node type NodeSpecificRequest struct { Datacenter string Node string QueryOptions } func (r *NodeSpecificRequest) RequestDatacenter() string { return r.Datacenter } // ChecksInStateRequest is used to query for nodes in a state type ChecksInStateRequest struct { Datacenter string NodeMetaFilters map[string]string State string Source QuerySource QueryOptions } func (r *ChecksInStateRequest) RequestDatacenter() string { return r.Datacenter } // Used to return information about a node type Node struct { ID types.NodeID Node string Address string Datacenter string TaggedAddresses map[string]string Meta map[string]string RaftIndex } type Nodes []*Node // ValidateMeta validates a set of key/value pairs from the agent config func ValidateMetadata(meta map[string]string, allowConsulPrefix bool) error { if len(meta) > metaMaxKeyPairs { return fmt.Errorf("Node metadata cannot contain more than %d key/value pairs", metaMaxKeyPairs) } for key, value := range meta { if err := validateMetaPair(key, value, allowConsulPrefix); err != nil { return fmt.Errorf("Couldn't load metadata pair ('%s', '%s'): %s", key, value, err) } } return nil } // validateMetaPair checks that the given key/value pair is in a valid format func validateMetaPair(key, value string, allowConsulPrefix bool) error { if key == "" { return fmt.Errorf("Key cannot be blank") } if !metaKeyFormat(key) { return fmt.Errorf("Key contains invalid characters") } if len(key) > metaKeyMaxLength { return fmt.Errorf("Key is too long (limit: %d characters)", metaKeyMaxLength) } if strings.HasPrefix(key, metaKeyReservedPrefix) && !allowConsulPrefix { return fmt.Errorf("Key prefix '%s' is reserved for internal use", metaKeyReservedPrefix) } if len(value) > metaValueMaxLength { return fmt.Errorf("Value is too long (limit: %d characters)", metaValueMaxLength) } return nil } // SatisfiesMetaFilters returns true if the metadata map contains the given filters func SatisfiesMetaFilters(meta map[string]string, filters map[string]string) bool { for key, value := range filters { if v, ok := meta[key]; !ok || v != value { return false } } return true } // Used to return information about a provided services. // Maps service name to available tags type Services map[string][]string // ServiceNode represents a node that is part of a service. ID, Address, // TaggedAddresses, and NodeMeta are node-related fields that are always empty // in the state store and are filled in on the way out by parseServiceNodes(). // This is also why PartialClone() skips them, because we know they are blank // already so it would be a waste of time to copy them. type ServiceNode struct { ID types.NodeID Node string Address string Datacenter string TaggedAddresses map[string]string NodeMeta map[string]string ServiceKind ServiceKind ServiceID string ServiceName string ServiceTags []string ServiceAddress string ServiceMeta map[string]string ServicePort int ServiceEnableTagOverride bool ServiceProxyDestination string RaftIndex } // PartialClone() returns a clone of the given service node, minus the node- // related fields that get filled in later, Address and TaggedAddresses. func (s *ServiceNode) PartialClone() *ServiceNode { tags := make([]string, len(s.ServiceTags)) copy(tags, s.ServiceTags) nsmeta := make(map[string]string) for k, v := range s.ServiceMeta { nsmeta[k] = v } return &ServiceNode{ // Skip ID, see above. Node: s.Node, // Skip Address, see above. // Skip TaggedAddresses, see above. ServiceKind: s.ServiceKind, ServiceID: s.ServiceID, ServiceName: s.ServiceName, ServiceTags: tags, ServiceAddress: s.ServiceAddress, ServicePort: s.ServicePort, ServiceMeta: nsmeta, ServiceEnableTagOverride: s.ServiceEnableTagOverride, ServiceProxyDestination: s.ServiceProxyDestination, RaftIndex: RaftIndex{ CreateIndex: s.CreateIndex, ModifyIndex: s.ModifyIndex, }, } } // ToNodeService converts the given service node to a node service. func (s *ServiceNode) ToNodeService() *NodeService { return &NodeService{ Kind: s.ServiceKind, ID: s.ServiceID, Service: s.ServiceName, Tags: s.ServiceTags, Address: s.ServiceAddress, Port: s.ServicePort, Meta: s.ServiceMeta, EnableTagOverride: s.ServiceEnableTagOverride, ProxyDestination: s.ServiceProxyDestination, RaftIndex: RaftIndex{ CreateIndex: s.CreateIndex, ModifyIndex: s.ModifyIndex, }, } } type ServiceNodes []*ServiceNode // ServiceKind is the kind of service being registered. type ServiceKind string const ( // ServiceKindTypical is a typical, classic Consul service. This is // represented by the absence of a value. This was chosen for ease of // backwards compatibility: existing services in the catalog would // default to the typical service. ServiceKindTypical ServiceKind = "" // ServiceKindConnectProxy is a proxy for the Connect feature. This // service proxies another service within Consul and speaks the connect // protocol. ServiceKindConnectProxy ServiceKind = "connect-proxy" ) // NodeService is a service provided by a node type NodeService struct { // Kind is the kind of service this is. Different kinds of services may // have differing validation, DNS behavior, etc. An empty kind will default // to the Default kind. See ServiceKind for the full list of kinds. Kind ServiceKind ID string Service string Tags []string Address string Meta map[string]string Port int EnableTagOverride bool // ProxyDestination is the name of the service that this service is // a Connect proxy for. This is only valid if Kind is "connect-proxy". // The destination may be a service that isn't present in the catalog. // This is expected and allowed to allow for proxies to come up // earlier than their target services. ProxyDestination string RaftIndex } // Validate validates the node service configuration. // // NOTE(mitchellh): This currently only validates fields for a ConnectProxy. // Historically validation has been directly in the Catalog.Register RPC. // ConnectProxy validation was moved here for easier table testing, but // other validation still exists in Catalog.Register. func (s *NodeService) Validate() error { var result error // ConnectProxy validation if s.Kind == ServiceKindConnectProxy { if strings.TrimSpace(s.ProxyDestination) == "" { result = multierror.Append(result, fmt.Errorf( "ProxyDestination must be non-empty for Connect proxy services")) } if s.Port == 0 { result = multierror.Append(result, fmt.Errorf( "Port must be set for a Connect proxy")) } } return result } // IsSame checks if one NodeService is the same as another, without looking // at the Raft information (that's why we didn't call it IsEqual). This is // useful for seeing if an update would be idempotent for all the functional // parts of the structure. func (s *NodeService) IsSame(other *NodeService) bool { if s.ID != other.ID || s.Service != other.Service || !reflect.DeepEqual(s.Tags, other.Tags) || s.Address != other.Address || s.Port != other.Port || !reflect.DeepEqual(s.Meta, other.Meta) || s.EnableTagOverride != other.EnableTagOverride || s.Kind != other.Kind || s.ProxyDestination != other.ProxyDestination { return false } return true } // ToServiceNode converts the given node service to a service node. func (s *NodeService) ToServiceNode(node string) *ServiceNode { return &ServiceNode{ // Skip ID, see ServiceNode definition. Node: node, // Skip Address, see ServiceNode definition. // Skip TaggedAddresses, see ServiceNode definition. ServiceKind: s.Kind, ServiceID: s.ID, ServiceName: s.Service, ServiceTags: s.Tags, ServiceAddress: s.Address, ServicePort: s.Port, ServiceMeta: s.Meta, ServiceEnableTagOverride: s.EnableTagOverride, ServiceProxyDestination: s.ProxyDestination, RaftIndex: RaftIndex{ CreateIndex: s.CreateIndex, ModifyIndex: s.ModifyIndex, }, } } type NodeServices struct { Node *Node Services map[string]*NodeService } // HealthCheck represents a single check on a given node type HealthCheck struct { Node string CheckID types.CheckID // Unique per-node ID Name string // Check name Status string // The current check status Notes string // Additional notes with the status Output string // Holds output of script runs ServiceID string // optional associated service ServiceName string // optional service name ServiceTags []string // optional service tags Definition HealthCheckDefinition RaftIndex } type HealthCheckDefinition struct { HTTP string `json:",omitempty"` TLSSkipVerify bool `json:",omitempty"` Header map[string][]string `json:",omitempty"` Method string `json:",omitempty"` TCP string `json:",omitempty"` Interval api.ReadableDuration `json:",omitempty"` Timeout api.ReadableDuration `json:",omitempty"` DeregisterCriticalServiceAfter api.ReadableDuration `json:",omitempty"` } // IsSame checks if one HealthCheck is the same as another, without looking // at the Raft information (that's why we didn't call it IsEqual). This is // useful for seeing if an update would be idempotent for all the functional // parts of the structure. func (c *HealthCheck) IsSame(other *HealthCheck) bool { if c.Node != other.Node || c.CheckID != other.CheckID || c.Name != other.Name || c.Status != other.Status || c.Notes != other.Notes || c.Output != other.Output || c.ServiceID != other.ServiceID || c.ServiceName != other.ServiceName || !reflect.DeepEqual(c.ServiceTags, other.ServiceTags) { return false } return true } // Clone returns a distinct clone of the HealthCheck. func (c *HealthCheck) Clone() *HealthCheck { clone := new(HealthCheck) *clone = *c return clone } // HealthChecks is a collection of HealthCheck structs. type HealthChecks []*HealthCheck // CheckServiceNode is used to provide the node, its service // definition, as well as a HealthCheck that is associated. type CheckServiceNode struct { Node *Node Service *NodeService Checks HealthChecks } type CheckServiceNodes []CheckServiceNode // Shuffle does an in-place random shuffle using the Fisher-Yates algorithm. func (nodes CheckServiceNodes) Shuffle() { for i := len(nodes) - 1; i > 0; i-- { j := rand.Int31n(int32(i + 1)) nodes[i], nodes[j] = nodes[j], nodes[i] } } // Filter removes nodes that are failing health checks (and any non-passing // check if that option is selected). Note that this returns the filtered // results AND modifies the receiver for performance. func (nodes CheckServiceNodes) Filter(onlyPassing bool) CheckServiceNodes { return nodes.FilterIgnore(onlyPassing, nil) } // FilterIgnore removes nodes that are failing health checks just like Filter. // It also ignores the status of any check with an ID present in ignoreCheckIDs // as if that check didn't exist. Note that this returns the filtered results // AND modifies the receiver for performance. func (nodes CheckServiceNodes) FilterIgnore(onlyPassing bool, ignoreCheckIDs []types.CheckID) CheckServiceNodes { n := len(nodes) OUTER: for i := 0; i < n; i++ { node := nodes[i] INNER: for _, check := range node.Checks { for _, ignore := range ignoreCheckIDs { if check.CheckID == ignore { // Skip this _check_ but keep looking at other checks for this node. continue INNER } } if check.Status == api.HealthCritical || (onlyPassing && check.Status != api.HealthPassing) { nodes[i], nodes[n-1] = nodes[n-1], CheckServiceNode{} n-- i-- // Skip this _node_ now we've swapped it off the end of the list. continue OUTER } } } return nodes[:n] } // NodeInfo is used to dump all associated information about // a node. This is currently used for the UI only, as it is // rather expensive to generate. type NodeInfo struct { ID types.NodeID Node string Address string TaggedAddresses map[string]string Meta map[string]string Services []*NodeService Checks HealthChecks } // NodeDump is used to dump all the nodes with all their // associated data. This is currently used for the UI only, // as it is rather expensive to generate. type NodeDump []*NodeInfo type IndexedNodes struct { Nodes Nodes QueryMeta } type IndexedServices struct { Services Services QueryMeta } type IndexedServiceNodes struct { ServiceNodes ServiceNodes QueryMeta } type IndexedNodeServices struct { // TODO: This should not be a pointer, see comments in // agent/catalog_endpoint.go. NodeServices *NodeServices QueryMeta } type IndexedHealthChecks struct { HealthChecks HealthChecks QueryMeta } type IndexedCheckServiceNodes struct { Nodes CheckServiceNodes QueryMeta } type IndexedNodeDump struct { Dump NodeDump QueryMeta } // DirEntry is used to represent a directory entry. This is // used for values in our Key-Value store. type DirEntry struct { LockIndex uint64 Key string Flags uint64 Value []byte Session string `json:",omitempty"` RaftIndex } // Returns a clone of the given directory entry. func (d *DirEntry) Clone() *DirEntry { return &DirEntry{ LockIndex: d.LockIndex, Key: d.Key, Flags: d.Flags, Value: d.Value, Session: d.Session, RaftIndex: RaftIndex{ CreateIndex: d.CreateIndex, ModifyIndex: d.ModifyIndex, }, } } type DirEntries []*DirEntry // KVSRequest is used to operate on the Key-Value store type KVSRequest struct { Datacenter string Op api.KVOp // Which operation are we performing DirEnt DirEntry // Which directory entry WriteRequest } func (r *KVSRequest) RequestDatacenter() string { return r.Datacenter } // KeyRequest is used to request a key, or key prefix type KeyRequest struct { Datacenter string Key string QueryOptions } func (r *KeyRequest) RequestDatacenter() string { return r.Datacenter } // KeyListRequest is used to list keys type KeyListRequest struct { Datacenter string Prefix string Seperator string QueryOptions } func (r *KeyListRequest) RequestDatacenter() string { return r.Datacenter } type IndexedDirEntries struct { Entries DirEntries QueryMeta } type IndexedKeyList struct { Keys []string QueryMeta } type SessionBehavior string const ( SessionKeysRelease SessionBehavior = "release" SessionKeysDelete = "delete" ) const ( SessionTTLMax = 24 * time.Hour SessionTTLMultiplier = 2 ) // Session is used to represent an open session in the KV store. // This issued to associate node checks with acquired locks. type Session struct { ID string Name string Node string Checks []types.CheckID LockDelay time.Duration Behavior SessionBehavior // What to do when session is invalidated TTL string RaftIndex } type Sessions []*Session type SessionOp string const ( SessionCreate SessionOp = "create" SessionDestroy = "destroy" ) // SessionRequest is used to operate on sessions type SessionRequest struct { Datacenter string Op SessionOp // Which operation are we performing Session Session // Which session WriteRequest } func (r *SessionRequest) RequestDatacenter() string { return r.Datacenter } // SessionSpecificRequest is used to request a session by ID type SessionSpecificRequest struct { Datacenter string Session string QueryOptions } func (r *SessionSpecificRequest) RequestDatacenter() string { return r.Datacenter } type IndexedSessions struct { Sessions Sessions QueryMeta } // Coordinate stores a node name with its associated network coordinate. type Coordinate struct { Node string Segment string Coord *coordinate.Coordinate } type Coordinates []*Coordinate // IndexedCoordinate is used to represent a single node's coordinate from the state // store. type IndexedCoordinate struct { Coord *coordinate.Coordinate QueryMeta } // IndexedCoordinates is used to represent a list of nodes and their // corresponding raw coordinates. type IndexedCoordinates struct { Coordinates Coordinates QueryMeta } // DatacenterMap is used to represent a list of nodes with their raw coordinates, // associated with a datacenter. Coordinates are only compatible between nodes in // the same area. type DatacenterMap struct { Datacenter string AreaID types.AreaID Coordinates Coordinates } // CoordinateUpdateRequest is used to update the network coordinate of a given // node. type CoordinateUpdateRequest struct { Datacenter string Node string Segment string Coord *coordinate.Coordinate WriteRequest } // RequestDatacenter returns the datacenter for a given update request. func (c *CoordinateUpdateRequest) RequestDatacenter() string { return c.Datacenter } // EventFireRequest is used to ask a server to fire // a Serf event. It is a bit odd, since it doesn't depend on // the catalog or leader. Any node can respond, so it's not quite // like a standard write request. This is used only internally. type EventFireRequest struct { Datacenter string Name string Payload []byte // Not using WriteRequest so that any server can process // the request. It is a bit unusual... QueryOptions } func (r *EventFireRequest) RequestDatacenter() string { return r.Datacenter } // EventFireResponse is used to respond to a fire request. type EventFireResponse struct { QueryMeta } type TombstoneOp string const ( TombstoneReap TombstoneOp = "reap" ) // TombstoneRequest is used to trigger a reaping of the tombstones type TombstoneRequest struct { Datacenter string Op TombstoneOp ReapIndex uint64 WriteRequest } func (r *TombstoneRequest) RequestDatacenter() string { return r.Datacenter } // msgpackHandle is a shared handle for encoding/decoding of structs var msgpackHandle = &codec.MsgpackHandle{} // Decode is used to decode a MsgPack encoded object func Decode(buf []byte, out interface{}) error { return codec.NewDecoder(bytes.NewReader(buf), msgpackHandle).Decode(out) } // Encode is used to encode a MsgPack object with type prefix func Encode(t MessageType, msg interface{}) ([]byte, error) { var buf bytes.Buffer buf.WriteByte(uint8(t)) err := codec.NewEncoder(&buf, msgpackHandle).Encode(msg) return buf.Bytes(), err } // CompoundResponse is an interface for gathering multiple responses. It is // used in cross-datacenter RPC calls where more than 1 datacenter is // expected to reply. type CompoundResponse interface { // Add adds a new response to the compound response Add(interface{}) // New returns an empty response object which can be passed around by // reference, and then passed to Add() later on. New() interface{} } type KeyringOp string const ( KeyringList KeyringOp = "list" KeyringInstall = "install" KeyringUse = "use" KeyringRemove = "remove" ) // KeyringRequest encapsulates a request to modify an encryption keyring. // It can be used for install, remove, or use key type operations. type KeyringRequest struct { Operation KeyringOp Key string Datacenter string Forwarded bool RelayFactor uint8 QueryOptions } func (r *KeyringRequest) RequestDatacenter() string { return r.Datacenter } // KeyringResponse is a unified key response and can be used for install, // remove, use, as well as listing key queries. type KeyringResponse struct { WAN bool Datacenter string Segment string Messages map[string]string `json:",omitempty"` Keys map[string]int NumNodes int Error string `json:",omitempty"` } // KeyringResponses holds multiple responses to keyring queries. Each // datacenter replies independently, and KeyringResponses is used as a // container for the set of all responses. type KeyringResponses struct { Responses []*KeyringResponse QueryMeta } func (r *KeyringResponses) Add(v interface{}) { val := v.(*KeyringResponses) r.Responses = append(r.Responses, val.Responses...) } func (r *KeyringResponses) New() interface{} { return new(KeyringResponses) }