open-consul/agent/consul/server_serf.go
Daniel Nephin f21097beda acl: remove reading of serf acl tags
We no long need to read the acl serf tag, because servers are always either ACL enabled or
ACL disabled.

We continue to write the tag so that during an upgarde older servers will see the tag.
2021-09-29 15:45:11 -04:00

455 lines
13 KiB
Go

package consul
import (
"fmt"
"net"
"path/filepath"
"strings"
"time"
"github.com/hashicorp/go-hclog"
"github.com/hashicorp/memberlist"
"github.com/hashicorp/raft"
"github.com/hashicorp/serf/serf"
"github.com/hashicorp/consul/agent/consul/wanfed"
"github.com/hashicorp/consul/agent/metadata"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/lib"
libserf "github.com/hashicorp/consul/lib/serf"
"github.com/hashicorp/consul/logging"
)
const (
// StatusReap is used to update the status of a node if we
// are handling a EventMemberReap
StatusReap = serf.MemberStatus(-1)
// userEventPrefix is pre-pended to a user event to distinguish it
userEventPrefix = "consul:event:"
// maxPeerRetries limits how many invalidate attempts are made
maxPeerRetries = 6
)
// setupSerf is used to setup and initialize a Serf
func (s *Server) setupSerf(conf *serf.Config, ch chan serf.Event, path string, wan bool, wanPort int,
segment string, listener net.Listener) (*serf.Serf, error) {
conf.Init()
if wan {
conf.NodeName = fmt.Sprintf("%s.%s", s.config.NodeName, s.config.Datacenter)
} else {
conf.NodeName = s.config.NodeName
if wanPort > 0 {
conf.Tags["wan_join_port"] = fmt.Sprintf("%d", wanPort)
}
}
conf.Tags["role"] = "consul"
conf.Tags["dc"] = s.config.Datacenter
conf.Tags["segment"] = segment
conf.Tags["id"] = string(s.config.NodeID)
conf.Tags["vsn"] = fmt.Sprintf("%d", s.config.ProtocolVersion)
conf.Tags["vsn_min"] = fmt.Sprintf("%d", ProtocolVersionMin)
conf.Tags["vsn_max"] = fmt.Sprintf("%d", ProtocolVersionMax)
conf.Tags["raft_vsn"] = fmt.Sprintf("%d", s.config.RaftConfig.ProtocolVersion)
conf.Tags["build"] = s.config.Build
addr := listener.Addr().(*net.TCPAddr)
conf.Tags["port"] = fmt.Sprintf("%d", addr.Port)
if s.config.Bootstrap {
conf.Tags["bootstrap"] = "1"
}
if s.config.BootstrapExpect != 0 {
conf.Tags["expect"] = fmt.Sprintf("%d", s.config.BootstrapExpect)
}
if s.config.ReadReplica {
// DEPRECATED - This tag should be removed when we no longer want to support
// upgrades from 1.8.x and below
conf.Tags["nonvoter"] = "1"
conf.Tags["read_replica"] = "1"
}
if s.config.TLSConfig.CAPath != "" || s.config.TLSConfig.CAFile != "" {
conf.Tags["use_tls"] = "1"
}
// TODO(ACL-Legacy-Compat): remove in phase 2. These are kept for now to
// allow for upgrades.
if s.acls.ACLsEnabled() {
conf.Tags[metadata.TagACLs] = string(structs.ACLModeEnabled)
} else {
conf.Tags[metadata.TagACLs] = string(structs.ACLModeDisabled)
}
// feature flag: advertise support for federation states
conf.Tags["ft_fs"] = "1"
// feature flag: advertise support for service-intentions
conf.Tags["ft_si"] = "1"
var subLoggerName string
if wan {
subLoggerName = logging.WAN
} else {
subLoggerName = logging.LAN
}
// Wrap hclog in a standard logger wrapper for serf and memberlist
// We use the Intercept variant here to ensure that serf and memberlist logs
// can be streamed via the monitor endpoint
serfLogger := s.logger.
NamedIntercept(logging.Serf).
NamedIntercept(subLoggerName).
StandardLoggerIntercept(&hclog.StandardLoggerOptions{InferLevels: true})
memberlistLogger := s.logger.
NamedIntercept(logging.Memberlist).
NamedIntercept(subLoggerName).
StandardLoggerIntercept(&hclog.StandardLoggerOptions{InferLevels: true})
conf.MemberlistConfig.Logger = memberlistLogger
conf.Logger = serfLogger
conf.EventCh = ch
conf.ProtocolVersion = protocolVersionMap[s.config.ProtocolVersion]
conf.RejoinAfterLeave = s.config.RejoinAfterLeave
if wan {
conf.Merge = &wanMergeDelegate{}
} else {
conf.Merge = &lanMergeDelegate{
dc: s.config.Datacenter,
nodeID: s.config.NodeID,
nodeName: s.config.NodeName,
segment: segment,
server: true,
}
}
if wan {
nt, err := memberlist.NewNetTransport(&memberlist.NetTransportConfig{
BindAddrs: []string{conf.MemberlistConfig.BindAddr},
BindPort: conf.MemberlistConfig.BindPort,
Logger: conf.MemberlistConfig.Logger,
})
if err != nil {
return nil, err
}
if s.config.ConnectMeshGatewayWANFederationEnabled {
mgwTransport, err := wanfed.NewTransport(
s.tlsConfigurator,
nt,
s.config.Datacenter,
s.gatewayLocator.PickGateway,
)
if err != nil {
return nil, err
}
conf.MemberlistConfig.Transport = mgwTransport
} else {
conf.MemberlistConfig.Transport = nt
}
}
// Until Consul supports this fully, we disable automatic resolution.
// When enabled, the Serf gossip may just turn off if we are the minority
// node which is rather unexpected.
conf.EnableNameConflictResolution = false
if wan && s.config.ConnectMeshGatewayWANFederationEnabled {
conf.MemberlistConfig.RequireNodeNames = true
conf.MemberlistConfig.DisableTcpPingsForNode = func(nodeName string) bool {
_, dc, err := wanfed.SplitNodeName(nodeName)
if err != nil {
return false // don't disable anything if we don't understand the node name
}
// If doing cross-dc we will be using TCP via the gateways so
// there's no need for an extra TCP request.
return s.config.Datacenter != dc
}
}
if !s.config.DevMode {
conf.SnapshotPath = filepath.Join(s.config.DataDir, path)
}
if err := lib.EnsurePath(conf.SnapshotPath, false); err != nil {
return nil, err
}
conf.ReconnectTimeoutOverride = libserf.NewReconnectOverride(s.logger)
addEnterpriseSerfTags(conf.Tags, s.config.AgentEnterpriseMeta())
if s.config.OverrideInitialSerfTags != nil {
s.config.OverrideInitialSerfTags(conf.Tags)
}
return serf.Create(conf)
}
// userEventName computes the name of a user event
func userEventName(name string) string {
return userEventPrefix + name
}
// isUserEvent checks if a serf event is a user event
func isUserEvent(name string) bool {
return strings.HasPrefix(name, userEventPrefix)
}
// rawUserEventName is used to get the raw user event name
func rawUserEventName(name string) string {
return strings.TrimPrefix(name, userEventPrefix)
}
// lanEventHandler is used to handle events from the lan Serf cluster
func (s *Server) lanEventHandler() {
for {
select {
case e := <-s.eventChLAN:
switch e.EventType() {
case serf.EventMemberJoin:
s.lanNodeJoin(e.(serf.MemberEvent))
s.localMemberEvent(e.(serf.MemberEvent))
case serf.EventMemberLeave, serf.EventMemberFailed, serf.EventMemberReap:
s.lanNodeFailed(e.(serf.MemberEvent))
s.localMemberEvent(e.(serf.MemberEvent))
case serf.EventUser:
s.localEvent(e.(serf.UserEvent))
case serf.EventMemberUpdate:
s.lanNodeUpdate(e.(serf.MemberEvent))
s.localMemberEvent(e.(serf.MemberEvent))
case serf.EventQuery: // Ignore
default:
s.logger.Warn("Unhandled LAN Serf Event", "event", e)
}
case <-s.shutdownCh:
return
}
}
}
// localMemberEvent is used to reconcile Serf events with the strongly
// consistent store if we are the current leader
func (s *Server) localMemberEvent(me serf.MemberEvent) {
// Do nothing if we are not the leader
if !s.IsLeader() {
return
}
// Check if this is a reap event
isReap := me.EventType() == serf.EventMemberReap
// Queue the members for reconciliation
for _, m := range me.Members {
// Change the status if this is a reap event
if isReap {
m.Status = StatusReap
}
select {
case s.reconcileCh <- m:
default:
}
}
}
// localEvent is called when we receive an event on the local Serf
func (s *Server) localEvent(event serf.UserEvent) {
// Handle only consul events
if !strings.HasPrefix(event.Name, "consul:") {
return
}
switch name := event.Name; {
case name == newLeaderEvent:
s.logger.Info("New leader elected", "payload", string(event.Payload))
// Trigger the callback
if s.config.ServerUp != nil {
s.config.ServerUp()
}
case isUserEvent(name):
event.Name = rawUserEventName(name)
s.logger.Debug("User event", "event", event.Name)
// Trigger the callback
if s.config.UserEventHandler != nil {
s.config.UserEventHandler(event)
}
default:
if !s.handleEnterpriseUserEvents(event) {
s.logger.Warn("Unhandled local event", "event", event)
}
}
}
// lanNodeJoin is used to handle join events on the LAN pool.
func (s *Server) lanNodeJoin(me serf.MemberEvent) {
for _, m := range me.Members {
ok, serverMeta := metadata.IsConsulServer(m)
if !ok || serverMeta.Segment != "" {
continue
}
s.logger.Info("Adding LAN server", "server", serverMeta.String())
// Update server lookup
s.serverLookup.AddServer(serverMeta)
// If we're still expecting to bootstrap, may need to handle this.
if s.config.BootstrapExpect != 0 {
s.maybeBootstrap()
}
// Kick the join flooders.
s.FloodNotify()
}
}
func (s *Server) lanNodeUpdate(me serf.MemberEvent) {
for _, m := range me.Members {
ok, serverMeta := metadata.IsConsulServer(m)
if !ok || serverMeta.Segment != "" {
continue
}
s.logger.Info("Updating LAN server", "server", serverMeta.String())
// Update server lookup
s.serverLookup.AddServer(serverMeta)
}
}
// maybeBootstrap is used to handle bootstrapping when a new consul server joins.
func (s *Server) maybeBootstrap() {
// Bootstrap can only be done if there are no committed logs, remove our
// expectations of bootstrapping. This is slightly cheaper than the full
// check that BootstrapCluster will do, so this is a good pre-filter.
index, err := s.raftStore.LastIndex()
if err != nil {
s.logger.Error("Failed to read last raft index", "error", err)
return
}
if index != 0 {
s.logger.Info("Raft data found, disabling bootstrap mode")
s.config.BootstrapExpect = 0
return
}
// Scan for all the known servers.
members := s.serfLAN.Members()
var servers []metadata.Server
voters := 0
for _, member := range members {
valid, p := metadata.IsConsulServer(member)
if !valid {
continue
}
if p.Datacenter != s.config.Datacenter {
s.logger.Warn("Member has a conflicting datacenter, ignoring", "member", member)
continue
}
if p.Expect != 0 && p.Expect != s.config.BootstrapExpect {
s.logger.Error("Member has a conflicting expect value. All nodes should expect the same number.", "member", member)
return
}
if p.Bootstrap {
s.logger.Error("Member has bootstrap mode. Expect disabled.", "member", member)
return
}
if !p.ReadReplica {
voters++
}
servers = append(servers, *p)
}
// Skip if we haven't met the minimum expect count.
if voters < s.config.BootstrapExpect {
return
}
// Query each of the servers and make sure they report no Raft peers.
for _, server := range servers {
var peers []string
// Retry with exponential backoff to get peer status from this server
for attempt := uint(0); attempt < maxPeerRetries; attempt++ {
if err := s.connPool.RPC(s.config.Datacenter, server.ShortName, server.Addr,
"Status.Peers", &structs.DCSpecificRequest{Datacenter: s.config.Datacenter}, &peers); err != nil {
nextRetry := (1 << attempt) * time.Second
s.logger.Error("Failed to confirm peer status for server (will retry).",
"server", server.Name,
"retry_interval", nextRetry.String(),
"error", err,
)
time.Sleep(nextRetry)
} else {
break
}
}
// Found a node with some Raft peers, stop bootstrap since there's
// evidence of an existing cluster. We should get folded in by the
// existing servers if that's the case, so it's cleaner to sit as a
// candidate with no peers so we don't cause spurious elections.
// It's OK this is racy, because even with an initial bootstrap
// as long as one peer runs bootstrap things will work, and if we
// have multiple peers bootstrap in the same way, that's OK. We
// just don't want a server added much later to do a live bootstrap
// and interfere with the cluster. This isn't required for Raft's
// correctness because no server in the existing cluster will vote
// for this server, but it makes things much more stable.
if len(peers) > 0 {
s.logger.Info("Existing Raft peers reported by server, disabling bootstrap mode", "server", server.Name)
s.config.BootstrapExpect = 0
return
}
}
// Attempt a live bootstrap!
var configuration raft.Configuration
var addrs []string
for _, server := range servers {
addr := server.Addr.String()
addrs = append(addrs, addr)
id := raft.ServerID(server.ID)
suffrage := raft.Voter
if server.ReadReplica {
suffrage = raft.Nonvoter
}
peer := raft.Server{
ID: id,
Address: raft.ServerAddress(addr),
Suffrage: suffrage,
}
configuration.Servers = append(configuration.Servers, peer)
}
s.logger.Info("Found expected number of peers, attempting bootstrap",
"peers", strings.Join(addrs, ","),
)
future := s.raft.BootstrapCluster(configuration)
if err := future.Error(); err != nil {
s.logger.Error("Failed to bootstrap cluster", "error", err)
}
// Bootstrapping complete, or failed for some reason, don't enter this
// again.
s.config.BootstrapExpect = 0
}
// lanNodeFailed is used to handle fail events on the LAN pool.
func (s *Server) lanNodeFailed(me serf.MemberEvent) {
for _, m := range me.Members {
ok, serverMeta := metadata.IsConsulServer(m)
if !ok || serverMeta.Segment != "" {
continue
}
s.logger.Info("Removing LAN server", "server", serverMeta.String())
// Update id to address map
s.serverLookup.RemoveServer(serverMeta)
}
}