open-consul/agent/consul/leader.go

1461 lines
45 KiB
Go

package consul
import (
"context"
"fmt"
"net"
"strconv"
"sync"
"sync/atomic"
"time"
"github.com/armon/go-metrics"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/agent/consul/autopilot"
"github.com/hashicorp/consul/agent/metadata"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/lib"
"github.com/hashicorp/consul/types"
"github.com/hashicorp/go-memdb"
"github.com/hashicorp/go-uuid"
"github.com/hashicorp/go-version"
"github.com/hashicorp/raft"
"github.com/hashicorp/serf/serf"
"golang.org/x/time/rate"
)
const (
newLeaderEvent = "consul:new-leader"
barrierWriteTimeout = 2 * time.Minute
)
var (
// caRootPruneInterval is how often we check for stale CARoots to remove.
caRootPruneInterval = time.Hour
// minAutopilotVersion is the minimum Consul version in which Autopilot features
// are supported.
minAutopilotVersion = version.Must(version.NewVersion("0.8.0"))
// minCentralizedConfigVersion is the minimum Consul version in which centralized
// config is supported
minCentralizedConfigVersion = version.Must(version.NewVersion("1.5.0"))
)
// monitorLeadership is used to monitor if we acquire or lose our role
// as the leader in the Raft cluster. There is some work the leader is
// expected to do, so we must react to changes
func (s *Server) monitorLeadership() {
// We use the notify channel we configured Raft with, NOT Raft's
// leaderCh, which is only notified best-effort. Doing this ensures
// that we get all notifications in order, which is required for
// cleanup and to ensure we never run multiple leader loops.
raftNotifyCh := s.raftNotifyCh
aclModeCheckWait := aclModeCheckMinInterval
var aclUpgradeCh <-chan time.Time
if s.ACLsEnabled() {
aclUpgradeCh = time.After(aclModeCheckWait)
}
var weAreLeaderCh chan struct{}
var leaderLoop sync.WaitGroup
for {
select {
case isLeader := <-raftNotifyCh:
switch {
case isLeader:
if weAreLeaderCh != nil {
s.logger.Printf("[ERR] consul: attempted to start the leader loop while running")
continue
}
weAreLeaderCh = make(chan struct{})
leaderLoop.Add(1)
go func(ch chan struct{}) {
defer leaderLoop.Done()
s.leaderLoop(ch)
}(weAreLeaderCh)
s.logger.Printf("[INFO] consul: cluster leadership acquired")
default:
if weAreLeaderCh == nil {
s.logger.Printf("[ERR] consul: attempted to stop the leader loop while not running")
continue
}
s.logger.Printf("[DEBUG] consul: shutting down leader loop")
close(weAreLeaderCh)
leaderLoop.Wait()
weAreLeaderCh = nil
s.logger.Printf("[INFO] consul: cluster leadership lost")
}
case <-aclUpgradeCh:
if atomic.LoadInt32(&s.useNewACLs) == 0 {
aclModeCheckWait = aclModeCheckWait * 2
if aclModeCheckWait > aclModeCheckMaxInterval {
aclModeCheckWait = aclModeCheckMaxInterval
}
aclUpgradeCh = time.After(aclModeCheckWait)
if canUpgrade := s.canUpgradeToNewACLs(weAreLeaderCh != nil); canUpgrade {
if weAreLeaderCh != nil {
if err := s.initializeACLs(true); err != nil {
s.logger.Printf("[ERR] consul: error transitioning to using new ACLs: %v", err)
continue
}
}
s.logger.Printf("[DEBUG] acl: transitioning out of legacy ACL mode")
atomic.StoreInt32(&s.useNewACLs, 1)
s.updateACLAdvertisement()
// setting this to nil ensures that we will never hit this case again
aclUpgradeCh = nil
}
} else {
// establishLeadership probably transitioned us
aclUpgradeCh = nil
}
case <-s.shutdownCh:
return
}
}
}
func (s *Server) leadershipTransfer() error {
retryCount := 3
for i := 0; i < retryCount; i++ {
future := s.raft.LeadershipTransfer()
if err := future.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to transfer leadership attempt %d/%d: %v", i, retryCount, err)
} else {
s.logger.Printf("[ERR] consul: successfully transferred leadership attempt %d/%d", i, retryCount)
return nil
}
}
return fmt.Errorf("failed to transfer leadership in %d attempts", retryCount)
}
// leaderLoop runs as long as we are the leader to run various
// maintenance activities
func (s *Server) leaderLoop(stopCh chan struct{}) {
// Fire a user event indicating a new leader
payload := []byte(s.config.NodeName)
for name, segment := range s.LANSegments() {
if err := segment.UserEvent(newLeaderEvent, payload, false); err != nil {
s.logger.Printf("[WARN] consul: failed to broadcast new leader event on segment %q: %v", name, err)
}
}
// Reconcile channel is only used once initial reconcile
// has succeeded
var reconcileCh chan serf.Member
establishedLeader := false
RECONCILE:
// Setup a reconciliation timer
reconcileCh = nil
interval := time.After(s.config.ReconcileInterval)
// Apply a raft barrier to ensure our FSM is caught up
start := time.Now()
barrier := s.raft.Barrier(barrierWriteTimeout)
if err := barrier.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to wait for barrier: %v", err)
goto WAIT
}
metrics.MeasureSince([]string{"leader", "barrier"}, start)
// Check if we need to handle initial leadership actions
if !establishedLeader {
if err := s.establishLeadership(); err != nil {
s.logger.Printf("[ERR] consul: failed to establish leadership: %v", err)
// Immediately revoke leadership since we didn't successfully
// establish leadership.
s.revokeLeadership()
// attempt to transfer leadership. If successful it is
// time to leave the leaderLoop since this node is no
// longer the leader. If leadershipTransfer() fails, we
// will try to acquire it again after
// 5 seconds.
if err := s.leadershipTransfer(); err != nil {
s.logger.Printf("[ERR] consul: %v", err)
interval = time.After(5 * time.Second)
goto WAIT
}
return
}
establishedLeader = true
defer s.revokeLeadership()
}
// Reconcile any missing data
if err := s.reconcile(); err != nil {
s.logger.Printf("[ERR] consul: failed to reconcile: %v", err)
goto WAIT
}
// Initial reconcile worked, now we can process the channel
// updates
reconcileCh = s.reconcileCh
WAIT:
// Poll the stop channel to give it priority so we don't waste time
// trying to perform the other operations if we have been asked to shut
// down.
select {
case <-stopCh:
return
default:
}
// Periodically reconcile as long as we are the leader,
// or when Serf events arrive
for {
select {
case <-stopCh:
return
case <-s.shutdownCh:
return
case <-interval:
goto RECONCILE
case member := <-reconcileCh:
s.reconcileMember(member)
case index := <-s.tombstoneGC.ExpireCh():
go s.reapTombstones(index)
case errCh := <-s.reassertLeaderCh:
// we can get into this state when the initial
// establishLeadership has failed as well as the follow
// up leadershipTransfer. Afterwards we will be waiting
// for the interval to trigger a reconciliation and can
// potentially end up here. There is no point to
// reassert because this agent was never leader in the
// first place.
if !establishedLeader {
errCh <- fmt.Errorf("leadership has not been established")
continue
}
// continue to reassert only if we previously were the
// leader, which means revokeLeadership followed by an
// establishLeadership().
s.revokeLeadership()
err := s.establishLeadership()
errCh <- err
// in case establishLeadership failed, we will try to
// transfer leadership. At this time raft thinks we are
// the leader, but consul disagrees.
if err != nil {
if err := s.leadershipTransfer(); err != nil {
// establishedLeader was true before,
// but it no longer is since it revoked
// leadership and Leadership transfer
// also failed. Which is why it stays
// in the leaderLoop, but now
// establishedLeader needs to be set to
// false.
establishedLeader = false
interval = time.After(5 * time.Second)
goto WAIT
}
// leadershipTransfer was successful and it is
// time to leave the leaderLoop.
return
}
}
}
}
// establishLeadership is invoked once we become leader and are able
// to invoke an initial barrier. The barrier is used to ensure any
// previously inflight transactions have been committed and that our
// state is up-to-date.
func (s *Server) establishLeadership() error {
// check for the upgrade here - this helps us transition to new ACLs much
// quicker if this is a new cluster or this is a test agent
if canUpgrade := s.canUpgradeToNewACLs(true); canUpgrade {
if err := s.initializeACLs(true); err != nil {
return err
}
atomic.StoreInt32(&s.useNewACLs, 1)
s.updateACLAdvertisement()
} else if err := s.initializeACLs(false); err != nil {
return err
}
// Hint the tombstone expiration timer. When we freshly establish leadership
// we become the authoritative timer, and so we need to start the clock
// on any pending GC events.
s.tombstoneGC.SetEnabled(true)
lastIndex := s.raft.LastIndex()
s.tombstoneGC.Hint(lastIndex)
// Setup the session timers. This is done both when starting up or when
// a leader fail over happens. Since the timers are maintained by the leader
// node along, effectively this means all the timers are renewed at the
// time of failover. The TTL contract is that the session will not be expired
// before the TTL, so expiring it later is allowable.
//
// This MUST be done after the initial barrier to ensure the latest Sessions
// are available to be initialized. Otherwise initialization may use stale
// data.
if err := s.initializeSessionTimers(); err != nil {
return err
}
if err := s.establishEnterpriseLeadership(); err != nil {
return err
}
// attempt to bootstrap config entries
if err := s.bootstrapConfigEntries(s.config.ConfigEntryBootstrap); err != nil {
return err
}
s.getOrCreateAutopilotConfig()
s.autopilot.Start()
// todo(kyhavlov): start a goroutine here for handling periodic CA rotation
if err := s.initializeCA(); err != nil {
return err
}
s.startConfigReplication()
s.startConnectLeader()
s.setConsistentReadReady()
return nil
}
// revokeLeadership is invoked once we step down as leader.
// This is used to cleanup any state that may be specific to a leader.
func (s *Server) revokeLeadership() {
// Disable the tombstone GC, since it is only useful as a leader
s.tombstoneGC.SetEnabled(false)
// Clear the session timers on either shutdown or step down, since we
// are no longer responsible for session expirations.
s.clearAllSessionTimers()
s.revokeEnterpriseLeadership()
s.stopConfigReplication()
s.stopConnectLeader()
s.setCAProvider(nil, nil)
s.stopACLTokenReaping()
s.stopACLUpgrade()
s.resetConsistentReadReady()
s.autopilot.Stop()
}
// DEPRECATED (ACL-Legacy-Compat) - Remove once old ACL compatibility is removed
func (s *Server) initializeLegacyACL() error {
if !s.ACLsEnabled() {
return nil
}
authDC := s.config.ACLDatacenter
// Create anonymous token if missing.
state := s.fsm.State()
_, token, err := state.ACLTokenGetBySecret(nil, anonymousToken, nil)
if err != nil {
return fmt.Errorf("failed to get anonymous token: %v", err)
}
// Ignoring expiration times to avoid an insertion collision.
if token == nil {
req := structs.ACLRequest{
Datacenter: authDC,
Op: structs.ACLSet,
ACL: structs.ACL{
ID: anonymousToken,
Name: "Anonymous Token",
Type: structs.ACLTokenTypeClient,
},
}
_, err := s.raftApply(structs.ACLRequestType, &req)
if err != nil {
return fmt.Errorf("failed to create anonymous token: %v", err)
}
s.logger.Printf("[INFO] acl: Created the anonymous token")
}
// Check for configured master token.
if master := s.config.ACLMasterToken; len(master) > 0 {
_, token, err = state.ACLTokenGetBySecret(nil, master, nil)
if err != nil {
return fmt.Errorf("failed to get master token: %v", err)
}
// Ignoring expiration times to avoid an insertion collision.
if token == nil {
req := structs.ACLRequest{
Datacenter: authDC,
Op: structs.ACLSet,
ACL: structs.ACL{
ID: master,
Name: "Master Token",
Type: structs.ACLTokenTypeManagement,
},
}
_, err := s.raftApply(structs.ACLRequestType, &req)
if err != nil {
return fmt.Errorf("failed to create master token: %v", err)
}
s.logger.Printf("[INFO] consul: Created ACL master token from configuration")
}
}
// Check to see if we need to initialize the ACL bootstrap info. This
// needs a Consul version check since it introduces a new Raft operation
// that'll produce an error on older servers, and it also makes a piece
// of state in the state store that will cause problems with older
// servers consuming snapshots, so we have to wait to create it.
var minVersion = version.Must(version.NewVersion("0.9.1"))
if ServersMeetMinimumVersion(s.LANMembers(), minVersion) {
canBootstrap, _, err := state.CanBootstrapACLToken()
if err != nil {
return fmt.Errorf("failed looking for ACL bootstrap info: %v", err)
}
if canBootstrap {
req := structs.ACLRequest{
Datacenter: authDC,
Op: structs.ACLBootstrapInit,
}
resp, err := s.raftApply(structs.ACLRequestType, &req)
if err != nil {
return fmt.Errorf("failed to initialize ACL bootstrap: %v", err)
}
switch v := resp.(type) {
case error:
return fmt.Errorf("failed to initialize ACL bootstrap: %v", v)
case bool:
if v {
s.logger.Printf("[INFO] consul: ACL bootstrap enabled")
} else {
s.logger.Printf("[INFO] consul: ACL bootstrap disabled, existing management tokens found")
}
default:
return fmt.Errorf("unexpected response trying to initialize ACL bootstrap: %T", v)
}
}
} else {
s.logger.Printf("[WARN] consul: Can't initialize ACL bootstrap until all servers are >= %s", minVersion.String())
}
return nil
}
// initializeACLs is used to setup the ACLs if we are the leader
// and need to do this.
func (s *Server) initializeACLs(upgrade bool) error {
if !s.ACLsEnabled() {
return nil
}
// Purge the cache, since it could've changed while we were not the
// leader.
s.acls.cache.Purge()
// Purge the auth method validators since they could've changed while we
// were not leader.
s.aclAuthMethodValidators.Purge()
// Remove any token affected by CVE-2019-8336
if !s.InACLDatacenter() {
_, token, err := s.fsm.State().ACLTokenGetBySecret(nil, redactedToken, nil)
if err == nil && token != nil {
req := structs.ACLTokenBatchDeleteRequest{
TokenIDs: []string{token.AccessorID},
}
_, err := s.raftApply(structs.ACLTokenDeleteRequestType, &req)
if err != nil {
return fmt.Errorf("failed to remove token with a redacted secret: %v", err)
}
}
}
if s.InACLDatacenter() {
if s.UseLegacyACLs() && !upgrade {
s.logger.Printf("[INFO] acl: initializing legacy acls")
return s.initializeLegacyACL()
}
s.logger.Printf("[INFO] acl: initializing acls")
// Create/Upgrade the builtin global-management policy
_, policy, err := s.fsm.State().ACLPolicyGetByID(nil, structs.ACLPolicyGlobalManagementID, structs.DefaultEnterpriseMeta())
if err != nil {
return fmt.Errorf("failed to get the builtin global-management policy")
}
if policy == nil || policy.Rules != structs.ACLPolicyGlobalManagement {
newPolicy := structs.ACLPolicy{
ID: structs.ACLPolicyGlobalManagementID,
Name: "global-management",
Description: "Builtin Policy that grants unlimited access",
Rules: structs.ACLPolicyGlobalManagement,
Syntax: acl.SyntaxCurrent,
EnterpriseMeta: *structs.DefaultEnterpriseMeta(),
}
if policy != nil {
newPolicy.Name = policy.Name
newPolicy.Description = policy.Description
}
newPolicy.SetHash(true)
req := structs.ACLPolicyBatchSetRequest{
Policies: structs.ACLPolicies{&newPolicy},
}
_, err := s.raftApply(structs.ACLPolicySetRequestType, &req)
if err != nil {
return fmt.Errorf("failed to create global-management policy: %v", err)
}
s.logger.Printf("[INFO] consul: Created ACL 'global-management' policy")
}
// Check for configured master token.
if master := s.config.ACLMasterToken; len(master) > 0 {
state := s.fsm.State()
if _, err := uuid.ParseUUID(master); err != nil {
s.logger.Printf("[WARN] consul: Configuring a non-UUID master token is deprecated")
}
_, token, err := state.ACLTokenGetBySecret(nil, master, nil)
if err != nil {
return fmt.Errorf("failed to get master token: %v", err)
}
// Ignoring expiration times to avoid an insertion collision.
if token == nil {
accessor, err := lib.GenerateUUID(s.checkTokenUUID)
if err != nil {
return fmt.Errorf("failed to generate the accessor ID for the master token: %v", err)
}
token := structs.ACLToken{
AccessorID: accessor,
SecretID: master,
Description: "Master Token",
Policies: []structs.ACLTokenPolicyLink{
{
ID: structs.ACLPolicyGlobalManagementID,
},
},
CreateTime: time.Now(),
Local: false,
// DEPRECATED (ACL-Legacy-Compat) - only needed for compatibility
Type: structs.ACLTokenTypeManagement,
EnterpriseMeta: *structs.DefaultEnterpriseMeta(),
}
token.SetHash(true)
done := false
if canBootstrap, _, err := state.CanBootstrapACLToken(); err == nil && canBootstrap {
req := structs.ACLTokenBootstrapRequest{
Token: token,
ResetIndex: 0,
}
if _, err := s.raftApply(structs.ACLBootstrapRequestType, &req); err == nil {
s.logger.Printf("[INFO] consul: Bootstrapped ACL master token from configuration")
done = true
} else {
if err.Error() != structs.ACLBootstrapNotAllowedErr.Error() &&
err.Error() != structs.ACLBootstrapInvalidResetIndexErr.Error() {
return fmt.Errorf("failed to bootstrap master token: %v", err)
}
}
}
if !done {
// either we didn't attempt to or setting the token with a bootstrap request failed.
req := structs.ACLTokenBatchSetRequest{
Tokens: structs.ACLTokens{&token},
CAS: false,
}
if _, err := s.raftApply(structs.ACLTokenSetRequestType, &req); err != nil {
return fmt.Errorf("failed to create master token: %v", err)
}
s.logger.Printf("[INFO] consul: Created ACL master token from configuration")
}
}
}
state := s.fsm.State()
_, token, err := state.ACLTokenGetBySecret(nil, structs.ACLTokenAnonymousID, nil)
if err != nil {
return fmt.Errorf("failed to get anonymous token: %v", err)
}
// Ignoring expiration times to avoid an insertion collision.
if token == nil {
// DEPRECATED (ACL-Legacy-Compat) - Don't need to query for previous "anonymous" token
// check for legacy token that needs an upgrade
_, legacyToken, err := state.ACLTokenGetBySecret(nil, anonymousToken, nil)
if err != nil {
return fmt.Errorf("failed to get anonymous token: %v", err)
}
// Ignoring expiration times to avoid an insertion collision.
// the token upgrade routine will take care of upgrading the token if a legacy version exists
if legacyToken == nil {
token = &structs.ACLToken{
AccessorID: structs.ACLTokenAnonymousID,
SecretID: anonymousToken,
Description: "Anonymous Token",
CreateTime: time.Now(),
EnterpriseMeta: *structs.DefaultEnterpriseMeta(),
}
token.SetHash(true)
req := structs.ACLTokenBatchSetRequest{
Tokens: structs.ACLTokens{token},
CAS: false,
}
_, err := s.raftApply(structs.ACLTokenSetRequestType, &req)
if err != nil {
return fmt.Errorf("failed to create anonymous token: %v", err)
}
s.logger.Printf("[INFO] consul: Created ACL anonymous token from configuration")
}
}
// launch the upgrade go routine to generate accessors for everything
s.startACLUpgrade()
} else {
if s.UseLegacyACLs() && !upgrade {
if s.IsACLReplicationEnabled() {
s.startLegacyACLReplication()
}
}
if upgrade {
s.stopACLReplication()
}
// ACL replication is now mandatory
s.startACLReplication()
}
s.startACLTokenReaping()
return nil
}
// This function is only intended to be run as a managed go routine, it will block until
// the context passed in indicates that it should exit.
func (s *Server) legacyACLTokenUpgrade(ctx context.Context) error {
limiter := rate.NewLimiter(aclUpgradeRateLimit, int(aclUpgradeRateLimit))
for {
if err := limiter.Wait(ctx); err != nil {
return err
}
// actually run the upgrade here
state := s.fsm.State()
tokens, waitCh, err := state.ACLTokenListUpgradeable(aclUpgradeBatchSize)
if err != nil {
s.logger.Printf("[WARN] acl: encountered an error while searching for tokens without accessor ids: %v", err)
}
// No need to check expiration time here, as that only exists for v2 tokens.
if len(tokens) == 0 {
ws := memdb.NewWatchSet()
ws.Add(state.AbandonCh())
ws.Add(waitCh)
ws.Add(ctx.Done())
// wait for more tokens to need upgrading or the aclUpgradeCh to be closed
ws.Watch(nil)
continue
}
var newTokens structs.ACLTokens
for _, token := range tokens {
// This should be entirely unnecessary but is just a small safeguard against changing accessor IDs
if token.AccessorID != "" {
continue
}
newToken := *token
if token.SecretID == anonymousToken {
newToken.AccessorID = structs.ACLTokenAnonymousID
} else {
accessor, err := lib.GenerateUUID(s.checkTokenUUID)
if err != nil {
s.logger.Printf("[WARN] acl: failed to generate accessor during token auto-upgrade: %v", err)
continue
}
newToken.AccessorID = accessor
}
// Assign the global-management policy to legacy management tokens
if len(newToken.Policies) == 0 &&
len(newToken.ServiceIdentities) == 0 &&
len(newToken.Roles) == 0 &&
newToken.Type == structs.ACLTokenTypeManagement {
newToken.Policies = append(newToken.Policies, structs.ACLTokenPolicyLink{ID: structs.ACLPolicyGlobalManagementID})
}
// need to copy these as we are going to do a CAS operation.
newToken.CreateIndex = token.CreateIndex
newToken.ModifyIndex = token.ModifyIndex
newToken.SetHash(true)
newTokens = append(newTokens, &newToken)
}
req := &structs.ACLTokenBatchSetRequest{Tokens: newTokens, CAS: true}
resp, err := s.raftApply(structs.ACLTokenSetRequestType, req)
if err != nil {
s.logger.Printf("[ERR] acl: failed to apply acl token upgrade batch: %v", err)
}
if err, ok := resp.(error); ok {
s.logger.Printf("[ERR] acl: failed to apply acl token upgrade batch: %v", err)
}
}
}
func (s *Server) startACLUpgrade() {
if s.config.PrimaryDatacenter != s.config.Datacenter {
// token upgrades should only run in the primary
return
}
s.leaderRoutineManager.Start(aclUpgradeRoutineName, s.legacyACLTokenUpgrade)
}
func (s *Server) stopACLUpgrade() {
s.leaderRoutineManager.Stop(aclUpgradeRoutineName)
}
// This function is only intended to be run as a managed go routine, it will block until
// the context passed in indicates that it should exit.
func (s *Server) runLegacyACLReplication(ctx context.Context) error {
var lastRemoteIndex uint64
limiter := rate.NewLimiter(rate.Limit(s.config.ACLReplicationRate), s.config.ACLReplicationBurst)
for {
if err := limiter.Wait(ctx); err != nil {
return err
}
if s.tokens.ReplicationToken() == "" {
continue
}
index, exit, err := s.replicateLegacyACLs(lastRemoteIndex, ctx)
if exit {
return nil
}
if err != nil {
lastRemoteIndex = 0
s.updateACLReplicationStatusError()
s.logger.Printf("[WARN] consul: Legacy ACL replication error (will retry if still leader): %v", err)
} else {
lastRemoteIndex = index
s.updateACLReplicationStatusIndex(structs.ACLReplicateLegacy, index)
s.logger.Printf("[DEBUG] consul: Legacy ACL replication completed through remote index %d", index)
}
}
}
func (s *Server) startLegacyACLReplication() {
if s.InACLDatacenter() {
return
}
// unlike some other leader routines this initializes some extra state
// and therefore we want to prevent re-initialization if things are already
// running
if s.leaderRoutineManager.IsRunning(legacyACLReplicationRoutineName) {
return
}
s.initReplicationStatus()
s.leaderRoutineManager.Start(legacyACLReplicationRoutineName, s.runLegacyACLReplication)
s.logger.Printf("[INFO] acl: started legacy ACL replication")
s.updateACLReplicationStatusRunning(structs.ACLReplicateLegacy)
}
func (s *Server) startACLReplication() {
if s.InACLDatacenter() {
return
}
// unlike some other leader routines this initializes some extra state
// and therefore we want to prevent re-initialization if things are already
// running
if s.leaderRoutineManager.IsRunning(aclPolicyReplicationRoutineName) {
return
}
s.initReplicationStatus()
s.leaderRoutineManager.Start(aclPolicyReplicationRoutineName, s.runACLPolicyReplicator)
s.leaderRoutineManager.Start(aclRoleReplicationRoutineName, s.runACLRoleReplicator)
if s.config.ACLTokenReplication {
s.leaderRoutineManager.Start(aclTokenReplicationRoutineName, s.runACLTokenReplicator)
s.updateACLReplicationStatusRunning(structs.ACLReplicateTokens)
} else {
s.updateACLReplicationStatusRunning(structs.ACLReplicatePolicies)
}
}
type replicateFunc func(ctx context.Context, lastRemoteIndex uint64) (uint64, bool, error)
// This function is only intended to be run as a managed go routine, it will block until
// the context passed in indicates that it should exit.
func (s *Server) runACLPolicyReplicator(ctx context.Context) error {
s.logger.Printf("[INFO] acl: started ACL Policy replication")
return s.runACLReplicator(ctx, structs.ACLReplicatePolicies, s.replicateACLPolicies)
}
// This function is only intended to be run as a managed go routine, it will block until
// the context passed in indicates that it should exit.
func (s *Server) runACLRoleReplicator(ctx context.Context) error {
s.logger.Printf("[INFO] acl: started ACL Role replication")
return s.runACLReplicator(ctx, structs.ACLReplicateRoles, s.replicateACLRoles)
}
// This function is only intended to be run as a managed go routine, it will block until
// the context passed in indicates that it should exit.
func (s *Server) runACLTokenReplicator(ctx context.Context) error {
return s.runACLReplicator(ctx, structs.ACLReplicateTokens, s.replicateACLTokens)
}
// This function is only intended to be run as a managed go routine, it will block until
// the context passed in indicates that it should exit.
func (s *Server) runACLReplicator(ctx context.Context, replicationType structs.ACLReplicationType, replicateFunc replicateFunc) error {
var failedAttempts uint
limiter := rate.NewLimiter(rate.Limit(s.config.ACLReplicationRate), s.config.ACLReplicationBurst)
var lastRemoteIndex uint64
for {
if err := limiter.Wait(ctx); err != nil {
return err
}
if s.tokens.ReplicationToken() == "" {
continue
}
index, exit, err := replicateFunc(ctx, lastRemoteIndex)
if exit {
return nil
}
if err != nil {
lastRemoteIndex = 0
s.updateACLReplicationStatusError()
s.logger.Printf("[WARN] consul: ACL %s replication error (will retry if still leader): %v", replicationType.SingularNoun(), err)
if (1 << failedAttempts) < aclReplicationMaxRetryBackoff {
failedAttempts++
}
select {
case <-ctx.Done():
return nil
case <-time.After((1 << failedAttempts) * time.Second):
// do nothing
}
} else {
lastRemoteIndex = index
s.updateACLReplicationStatusIndex(replicationType, index)
s.logger.Printf("[DEBUG] consul: ACL %s replication completed through remote index %d", replicationType.SingularNoun(), index)
failedAttempts = 0
}
}
}
func (s *Server) stopACLReplication() {
// these will be no-ops when not started
s.leaderRoutineManager.Stop(legacyACLReplicationRoutineName)
s.leaderRoutineManager.Stop(aclPolicyReplicationRoutineName)
s.leaderRoutineManager.Stop(aclRoleReplicationRoutineName)
s.leaderRoutineManager.Stop(aclTokenReplicationRoutineName)
}
func (s *Server) startConfigReplication() {
if s.config.PrimaryDatacenter == "" || s.config.PrimaryDatacenter == s.config.Datacenter {
// replication shouldn't run in the primary DC
return
}
s.leaderRoutineManager.Start(configReplicationRoutineName, s.configReplicator.Run)
}
func (s *Server) stopConfigReplication() {
// will be a no-op when not started
s.leaderRoutineManager.Stop(configReplicationRoutineName)
}
// getOrCreateAutopilotConfig is used to get the autopilot config, initializing it if necessary
func (s *Server) getOrCreateAutopilotConfig() *autopilot.Config {
state := s.fsm.State()
_, config, err := state.AutopilotConfig()
if err != nil {
s.logger.Printf("[ERR] autopilot: failed to get config: %v", err)
return nil
}
if config != nil {
return config
}
if !ServersMeetMinimumVersion(s.LANMembers(), minAutopilotVersion) {
s.logger.Printf("[WARN] autopilot: can't initialize until all servers are >= %s", minAutopilotVersion.String())
return nil
}
config = s.config.AutopilotConfig
req := structs.AutopilotSetConfigRequest{Config: *config}
if _, err = s.raftApply(structs.AutopilotRequestType, req); err != nil {
s.logger.Printf("[ERR] autopilot: failed to initialize config: %v", err)
return nil
}
return config
}
func (s *Server) bootstrapConfigEntries(entries []structs.ConfigEntry) error {
if s.config.PrimaryDatacenter != "" && s.config.PrimaryDatacenter != s.config.Datacenter {
// only bootstrap in the primary datacenter
return nil
}
if len(entries) < 1 {
// nothing to initialize
return nil
}
if !ServersMeetMinimumVersion(s.LANMembers(), minCentralizedConfigVersion) {
s.logger.Printf("[WARN] centralized config: can't initialize until all servers >= %s", minCentralizedConfigVersion.String())
return nil
}
state := s.fsm.State()
for _, entry := range entries {
// avoid a round trip through Raft if we know the CAS is going to fail
_, existing, err := state.ConfigEntry(nil, entry.GetKind(), entry.GetName())
if err != nil {
return fmt.Errorf("Failed to determine whether the configuration for %q / %q already exists: %v", entry.GetKind(), entry.GetName(), err)
}
if existing == nil {
// ensure the ModifyIndex is set to 0 for the CAS request
entry.GetRaftIndex().ModifyIndex = 0
req := structs.ConfigEntryRequest{
Op: structs.ConfigEntryUpsertCAS,
Datacenter: s.config.Datacenter,
Entry: entry,
}
resp, err := s.raftApply(structs.ConfigEntryRequestType, &req)
if err == nil {
if respErr, ok := resp.(error); ok {
err = respErr
}
}
if err != nil {
return fmt.Errorf("Failed to apply configuration entry %q / %q: %v", entry.GetKind(), entry.GetName(), err)
}
}
}
return nil
}
// reconcileReaped is used to reconcile nodes that have failed and been reaped
// from Serf but remain in the catalog. This is done by looking for unknown nodes with serfHealth checks registered.
// We generate a "reap" event to cause the node to be cleaned up.
func (s *Server) reconcileReaped(known map[string]struct{}) error {
state := s.fsm.State()
_, checks, err := state.ChecksInState(nil, api.HealthAny, structs.DefaultEnterpriseMeta())
if err != nil {
return err
}
for _, check := range checks {
// Ignore any non serf checks
if check.CheckID != structs.SerfCheckID {
continue
}
// Check if this node is "known" by serf
if _, ok := known[check.Node]; ok {
continue
}
// Get the node services, look for ConsulServiceID
_, services, err := state.NodeServices(nil, check.Node, structs.DefaultEnterpriseMeta())
if err != nil {
return err
}
serverPort := 0
serverAddr := ""
serverID := ""
CHECKS:
for _, service := range services.Services {
if service.ID == structs.ConsulServiceID {
_, node, err := state.GetNode(check.Node)
if err != nil {
s.logger.Printf("[ERR] consul: Unable to look up node with name %q: %v", check.Node, err)
continue CHECKS
}
serverAddr = node.Address
serverPort = service.Port
lookupAddr := net.JoinHostPort(serverAddr, strconv.Itoa(serverPort))
svr := s.serverLookup.Server(raft.ServerAddress(lookupAddr))
if svr != nil {
serverID = svr.ID
}
break
}
}
// Create a fake member
member := serf.Member{
Name: check.Node,
Tags: map[string]string{
"dc": s.config.Datacenter,
"role": "node",
},
}
// Create the appropriate tags if this was a server node
if serverPort > 0 {
member.Tags["role"] = "consul"
member.Tags["port"] = strconv.FormatUint(uint64(serverPort), 10)
member.Tags["id"] = serverID
member.Addr = net.ParseIP(serverAddr)
}
// Attempt to reap this member
if err := s.handleReapMember(member); err != nil {
return err
}
}
return nil
}
// reconcileMember is used to do an async reconcile of a single
// serf member
func (s *Server) reconcileMember(member serf.Member) error {
// Check if this is a member we should handle
if !s.shouldHandleMember(member) {
s.logger.Printf("[WARN] consul: skipping reconcile of node %v", member)
return nil
}
defer metrics.MeasureSince([]string{"leader", "reconcileMember"}, time.Now())
var err error
switch member.Status {
case serf.StatusAlive:
err = s.handleAliveMember(member)
case serf.StatusFailed:
err = s.handleFailedMember(member)
case serf.StatusLeft:
err = s.handleLeftMember(member)
case StatusReap:
err = s.handleReapMember(member)
}
if err != nil {
s.logger.Printf("[ERR] consul: failed to reconcile member: %v: %v",
member, err)
// Permission denied should not bubble up
if acl.IsErrPermissionDenied(err) {
return nil
}
}
return nil
}
// shouldHandleMember checks if this is a Consul pool member
func (s *Server) shouldHandleMember(member serf.Member) bool {
if valid, dc := isConsulNode(member); valid && dc == s.config.Datacenter {
return true
}
if valid, parts := metadata.IsConsulServer(member); valid &&
parts.Segment == "" &&
parts.Datacenter == s.config.Datacenter {
return true
}
return false
}
// handleAliveMember is used to ensure the node
// is registered, with a passing health check.
func (s *Server) handleAliveMember(member serf.Member) error {
// Register consul service if a server
var service *structs.NodeService
if valid, parts := metadata.IsConsulServer(member); valid {
service = &structs.NodeService{
ID: structs.ConsulServiceID,
Service: structs.ConsulServiceName,
Port: parts.Port,
Weights: &structs.Weights{
Passing: 1,
Warning: 1,
},
Meta: map[string]string{
"raft_version": strconv.Itoa(parts.RaftVersion),
"serf_protocol_current": strconv.FormatUint(uint64(member.ProtocolCur), 10),
"serf_protocol_min": strconv.FormatUint(uint64(member.ProtocolMin), 10),
"serf_protocol_max": strconv.FormatUint(uint64(member.ProtocolMax), 10),
"version": parts.Build.String(),
},
}
// Attempt to join the consul server
if err := s.joinConsulServer(member, parts); err != nil {
return err
}
}
// Check if the node exists
state := s.fsm.State()
_, node, err := state.GetNode(member.Name)
if err != nil {
return err
}
if node != nil && node.Address == member.Addr.String() {
// Check if the associated service is available
if service != nil {
match := false
_, services, err := state.NodeServices(nil, member.Name, structs.DefaultEnterpriseMeta())
if err != nil {
return err
}
if services != nil {
for id := range services.Services {
if id == service.ID {
match = true
}
}
}
if !match {
goto AFTER_CHECK
}
}
// Check if the serfCheck is in the passing state
_, checks, err := state.NodeChecks(nil, member.Name, structs.DefaultEnterpriseMeta())
if err != nil {
return err
}
for _, check := range checks {
if check.CheckID == structs.SerfCheckID && check.Status == api.HealthPassing {
return nil
}
}
}
AFTER_CHECK:
s.logger.Printf("[INFO] consul: member '%s' joined, marking health alive", member.Name)
// Register with the catalog.
req := structs.RegisterRequest{
Datacenter: s.config.Datacenter,
Node: member.Name,
ID: types.NodeID(member.Tags["id"]),
Address: member.Addr.String(),
Service: service,
Check: &structs.HealthCheck{
Node: member.Name,
CheckID: structs.SerfCheckID,
Name: structs.SerfCheckName,
Status: api.HealthPassing,
Output: structs.SerfCheckAliveOutput,
},
}
if node != nil {
req.TaggedAddresses = node.TaggedAddresses
req.NodeMeta = node.Meta
}
_, err = s.raftApply(structs.RegisterRequestType, &req)
return err
}
// handleFailedMember is used to mark the node's status
// as being critical, along with all checks as unknown.
func (s *Server) handleFailedMember(member serf.Member) error {
// Check if the node exists
state := s.fsm.State()
_, node, err := state.GetNode(member.Name)
if err != nil {
return err
}
if node == nil {
s.logger.Printf("[INFO] consul: ignoring failed event for member '%s' because it does not exist in the catalog", member.Name)
return nil
}
if node.Address == member.Addr.String() {
// Check if the serfCheck is in the critical state
_, checks, err := state.NodeChecks(nil, member.Name, structs.DefaultEnterpriseMeta())
if err != nil {
return err
}
for _, check := range checks {
if check.CheckID == structs.SerfCheckID && check.Status == api.HealthCritical {
return nil
}
}
}
s.logger.Printf("[INFO] consul: member '%s' failed, marking health critical", member.Name)
// Register with the catalog
req := structs.RegisterRequest{
Datacenter: s.config.Datacenter,
Node: member.Name,
ID: types.NodeID(member.Tags["id"]),
Address: member.Addr.String(),
Check: &structs.HealthCheck{
Node: member.Name,
CheckID: structs.SerfCheckID,
Name: structs.SerfCheckName,
Status: api.HealthCritical,
Output: structs.SerfCheckFailedOutput,
},
// If there's existing information about the node, do not
// clobber it.
SkipNodeUpdate: true,
}
_, err = s.raftApply(structs.RegisterRequestType, &req)
return err
}
// handleLeftMember is used to handle members that gracefully
// left. They are deregistered if necessary.
func (s *Server) handleLeftMember(member serf.Member) error {
return s.handleDeregisterMember("left", member)
}
// handleReapMember is used to handle members that have been
// reaped after a prolonged failure. They are deregistered.
func (s *Server) handleReapMember(member serf.Member) error {
return s.handleDeregisterMember("reaped", member)
}
// handleDeregisterMember is used to deregister a member of a given reason
func (s *Server) handleDeregisterMember(reason string, member serf.Member) error {
// Do not deregister ourself. This can only happen if the current leader
// is leaving. Instead, we should allow a follower to take-over and
// deregister us later.
if member.Name == s.config.NodeName {
s.logger.Printf("[WARN] consul: deregistering self (%s) should be done by follower", s.config.NodeName)
return nil
}
// Remove from Raft peers if this was a server
if valid, parts := metadata.IsConsulServer(member); valid {
if err := s.removeConsulServer(member, parts.Port); err != nil {
return err
}
}
// Check if the node does not exist
state := s.fsm.State()
_, node, err := state.GetNode(member.Name)
if err != nil {
return err
}
if node == nil {
return nil
}
// Deregister the node
s.logger.Printf("[INFO] consul: member '%s' %s, deregistering", member.Name, reason)
req := structs.DeregisterRequest{
Datacenter: s.config.Datacenter,
Node: member.Name,
}
_, err = s.raftApply(structs.DeregisterRequestType, &req)
return err
}
// joinConsulServer is used to try to join another consul server
func (s *Server) joinConsulServer(m serf.Member, parts *metadata.Server) error {
// Check for possibility of multiple bootstrap nodes
if parts.Bootstrap {
members := s.serfLAN.Members()
for _, member := range members {
valid, p := metadata.IsConsulServer(member)
if valid && member.Name != m.Name && p.Bootstrap {
s.logger.Printf("[ERR] consul: '%v' and '%v' are both in bootstrap mode. Only one node should be in bootstrap mode, not adding Raft peer.", m.Name, member.Name)
return nil
}
}
}
// Processing ourselves could result in trying to remove ourselves to
// fix up our address, which would make us step down. This is only
// safe to attempt if there are multiple servers available.
configFuture := s.raft.GetConfiguration()
if err := configFuture.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to get raft configuration: %v", err)
return err
}
if m.Name == s.config.NodeName {
if l := len(configFuture.Configuration().Servers); l < 3 {
s.logger.Printf("[DEBUG] consul: Skipping self join check for %q since the cluster is too small", m.Name)
return nil
}
}
// See if it's already in the configuration. It's harmless to re-add it
// but we want to avoid doing that if possible to prevent useless Raft
// log entries. If the address is the same but the ID changed, remove the
// old server before adding the new one.
addr := (&net.TCPAddr{IP: m.Addr, Port: parts.Port}).String()
minRaftProtocol, err := s.autopilot.MinRaftProtocol()
if err != nil {
return err
}
for _, server := range configFuture.Configuration().Servers {
// No-op if the raft version is too low
if server.Address == raft.ServerAddress(addr) && (minRaftProtocol < 2 || parts.RaftVersion < 3) {
return nil
}
// If the address or ID matches an existing server, see if we need to remove the old one first
if server.Address == raft.ServerAddress(addr) || server.ID == raft.ServerID(parts.ID) {
// Exit with no-op if this is being called on an existing server
if server.Address == raft.ServerAddress(addr) && server.ID == raft.ServerID(parts.ID) {
return nil
}
future := s.raft.RemoveServer(server.ID, 0, 0)
if server.Address == raft.ServerAddress(addr) {
if err := future.Error(); err != nil {
return fmt.Errorf("error removing server with duplicate address %q: %s", server.Address, err)
}
s.logger.Printf("[INFO] consul: removed server with duplicate address: %s", server.Address)
} else {
if err := future.Error(); err != nil {
return fmt.Errorf("error removing server with duplicate ID %q: %s", server.ID, err)
}
s.logger.Printf("[INFO] consul: removed server with duplicate ID: %s", server.ID)
}
}
}
// Attempt to add as a peer
switch {
case minRaftProtocol >= 3:
addFuture := s.raft.AddNonvoter(raft.ServerID(parts.ID), raft.ServerAddress(addr), 0, 0)
if err := addFuture.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to add raft peer: %v", err)
return err
}
case minRaftProtocol == 2 && parts.RaftVersion >= 3:
addFuture := s.raft.AddVoter(raft.ServerID(parts.ID), raft.ServerAddress(addr), 0, 0)
if err := addFuture.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to add raft peer: %v", err)
return err
}
default:
addFuture := s.raft.AddPeer(raft.ServerAddress(addr))
if err := addFuture.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to add raft peer: %v", err)
return err
}
}
// Trigger a check to remove dead servers
s.autopilot.RemoveDeadServers()
return nil
}
// removeConsulServer is used to try to remove a consul server that has left
func (s *Server) removeConsulServer(m serf.Member, port int) error {
addr := (&net.TCPAddr{IP: m.Addr, Port: port}).String()
// See if it's already in the configuration. It's harmless to re-remove it
// but we want to avoid doing that if possible to prevent useless Raft
// log entries.
configFuture := s.raft.GetConfiguration()
if err := configFuture.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to get raft configuration: %v", err)
return err
}
minRaftProtocol, err := s.autopilot.MinRaftProtocol()
if err != nil {
return err
}
_, parts := metadata.IsConsulServer(m)
// Pick which remove API to use based on how the server was added.
for _, server := range configFuture.Configuration().Servers {
// If we understand the new add/remove APIs and the server was added by ID, use the new remove API
if minRaftProtocol >= 2 && server.ID == raft.ServerID(parts.ID) {
s.logger.Printf("[INFO] consul: removing server by ID: %q", server.ID)
future := s.raft.RemoveServer(raft.ServerID(parts.ID), 0, 0)
if err := future.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to remove raft peer '%v': %v",
server.ID, err)
return err
}
break
} else if server.Address == raft.ServerAddress(addr) {
// If not, use the old remove API
s.logger.Printf("[INFO] consul: removing server by address: %q", server.Address)
future := s.raft.RemovePeer(raft.ServerAddress(addr))
if err := future.Error(); err != nil {
s.logger.Printf("[ERR] consul: failed to remove raft peer '%v': %v",
addr, err)
return err
}
break
}
}
return nil
}
// reapTombstones is invoked by the current leader to manage garbage
// collection of tombstones. When a key is deleted, we trigger a tombstone
// GC clock. Once the expiration is reached, this routine is invoked
// to clear all tombstones before this index. This must be replicated
// through Raft to ensure consistency. We do this outside the leader loop
// to avoid blocking.
func (s *Server) reapTombstones(index uint64) {
defer metrics.MeasureSince([]string{"leader", "reapTombstones"}, time.Now())
req := structs.TombstoneRequest{
Datacenter: s.config.Datacenter,
Op: structs.TombstoneReap,
ReapIndex: index,
}
_, err := s.raftApply(structs.TombstoneRequestType, &req)
if err != nil {
s.logger.Printf("[ERR] consul: failed to reap tombstones up to %d: %v",
index, err)
}
}