/
real.go
259 lines (217 loc) · 5.59 KB
/
real.go
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package members
import (
"fmt"
"io"
"sync"
"github.com/go-kit/kit/log"
"github.com/go-kit/kit/log/level"
"github.com/hashicorp/memberlist"
"github.com/hashicorp/serf/cmd/serf/command/agent"
"github.com/hashicorp/serf/serf"
"github.com/pkg/errors"
)
const (
defaultAgentLogLevel = "WARN"
)
type realMembers struct {
config Config
mutex sync.Mutex
agent *agent.Agent
members *serf.Serf
eventHandlers map[EventHandler]agent.EventHandler
logger log.Logger
}
// NewRealMembers creates a new members list to join.
func NewRealMembers(config Config, logger log.Logger) (Members, error) {
actor, err := agent.Create(transformConfig(config))
if err != nil {
return nil, err
}
if err := actor.Start(); err != nil {
return nil, err
}
return &realMembers{
config: config,
mutex: sync.Mutex{},
agent: actor,
members: actor.Serf(),
eventHandlers: make(map[EventHandler]agent.EventHandler),
logger: logger,
}, nil
}
func (r *realMembers) Join() (int, error) {
return r.members.Join(r.config.existing, true)
}
func (r *realMembers) Leave() error {
return r.members.Leave()
}
func (r *realMembers) MemberList() MemberList {
return &realMemberList{
r.members.Memberlist(),
r.logger,
}
}
func (r *realMembers) Walk(fn func(PeerInfo) error) error {
for _, v := range r.members.Members() {
if v.Status != serf.StatusAlive {
continue
}
if info, err := decodePeerInfoTag(v.Tags); err == nil {
if e := fn(info); e != nil {
return err
}
}
}
return nil
}
func (r *realMembers) Close() error {
if err := r.members.Leave(); err != nil {
level.Warn(r.logger).Log("err", err)
}
return r.members.Shutdown()
}
func (r *realMembers) RegisterEventHandler(fn EventHandler) error {
r.mutex.Lock()
defer r.mutex.Unlock()
eh := realEventHandler{
fn: fn,
logger: log.With(r.logger, "component", "event_handler"),
}
r.eventHandlers[fn] = eh
r.agent.RegisterEventHandler(eh)
return nil
}
func (r *realMembers) DeregisterEventHandler(fn EventHandler) error {
r.mutex.Lock()
defer r.mutex.Unlock()
if eh, ok := r.eventHandlers[fn]; ok {
delete(r.eventHandlers, fn)
r.agent.DeregisterEventHandler(eh)
}
return nil
}
func (r *realMembers) DispatchEvent(e Event) error {
switch t := e.(type) {
case *UserEvent:
return r.agent.UserEvent(t.Name, t.Payload, true)
default:
return errors.Errorf("Unsupported event type %v", e.Type())
}
}
type realMemberList struct {
list *memberlist.Memberlist
logger log.Logger
}
func (r *realMemberList) NumMembers() int {
return r.list.NumMembers()
}
func (r *realMemberList) LocalNode() Member {
return &realMember{r.list.LocalNode()}
}
func (r *realMemberList) Members() []Member {
m := r.list.Members()
n := make([]Member, len(m))
for k, v := range m {
n[k] = &realMember{v}
}
return n
}
type realMember struct {
member *memberlist.Node
}
func (r *realMember) Name() string {
return r.member.Name
}
func (r *realMember) Address() string {
return r.member.Address()
}
type realEventHandler struct {
fn EventHandler
logger log.Logger
}
func (h realEventHandler) HandleEvent(event serf.Event) {
switch t := event.(type) {
case serf.MemberEvent:
h.handleMemberEvent(t)
case serf.UserEvent:
h.processEvent(NewUserEvent(t.Name, t.Payload))
case *serf.Query:
h.processEvent(NewQueryEvent(t.Name, t.Payload, t))
case error:
h.processEvent(NewErrorEvent(t))
default:
level.Warn(h.logger).Log("reason", "unhandled event", "event_type", event.EventType())
}
}
func (h realEventHandler) handleMemberEvent(event serf.MemberEvent) {
var t MemberEventType
switch event.Type {
case serf.EventMemberJoin:
t = EventMemberJoined
case serf.EventMemberFailed:
t = EventMemberFailed
case serf.EventMemberLeave:
t = EventMemberLeft
case serf.EventMemberUpdate:
t = EventMemberUpdated
default:
// We don't know how to handle this, so bubble it up to the receiver.
err := errors.Errorf("unexpected member event %q", event.Type.String())
h.processEvent(NewErrorEvent(err))
return
}
var m []Member
for _, v := range event.Members {
m = append(m, eventMember{
name: v.Name,
addr: v.Addr.String(),
port: int(v.Port),
})
}
h.processEvent(NewMemberEvent(t, m))
}
func (h realEventHandler) processEvent(event Event) {
if event == nil {
return
}
if err := h.fn.HandleEvent(event); err != nil {
level.Warn(h.logger).Log("err", err)
}
}
func transformConfig(config Config) (*agent.Config, *serf.Config, io.Writer) {
agentConfig := agent.DefaultConfig()
agentConfig.LogLevel = defaultAgentLogLevel
if config.clientAddr != "" {
agentConfig.RPCAddr = fmt.Sprintf("%s:%d", config.clientAddr, config.clientPort)
}
serfConfig := serf.DefaultConfig()
serfConfig.NodeName = config.nodeName
serfConfig.MemberlistConfig.BindAddr = config.bindAddr
serfConfig.MemberlistConfig.BindPort = config.bindPort
if config.advertiseAddr != "" {
serfConfig.MemberlistConfig.AdvertiseAddr = config.advertiseAddr
serfConfig.MemberlistConfig.AdvertisePort = config.advertisePort
}
serfConfig.MemberlistConfig.LogOutput = config.logOutput
serfConfig.LogOutput = config.logOutput
serfConfig.BroadcastTimeout = config.broadcastTimeout
serfConfig.Tags = encodePeerInfoTag(PeerInfo{
Name: config.nodeName,
Type: config.peerType,
APIAddr: config.apiAddr,
APIPort: config.apiPort,
})
serfConfig.Init()
return agentConfig, serfConfig, config.logOutput
}
type eventMember struct {
name string
addr string
port int
}
func (e eventMember) Name() string {
return e.name
}
func (e eventMember) Address() string {
return fmt.Sprintf("%s:%d", e.addr, e.port)
}