open-consul/agent/local.go

795 lines
23 KiB
Go

package agent
import (
"fmt"
"log"
"reflect"
"strings"
"sync"
"sync/atomic"
"time"
"github.com/hashicorp/consul/agent/consul/structs"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/lib"
"github.com/hashicorp/consul/types"
)
const (
syncStaggerIntv = 3 * time.Second
syncRetryIntv = 15 * time.Second
)
// syncStatus is used to represent the difference between
// the local and remote state, and if action needs to be taken
type syncStatus struct {
inSync bool // Is this in sync with the server
}
// localStateConfig is the configuration for the localState. It is
// populated during NewLocalAgent from the agent configuration to avoid
// race conditions with the agent configuration.
type localStateConfig struct {
ACLToken string
AEInterval time.Duration
AdvertiseAddr string
CheckUpdateInterval time.Duration
Datacenter string
NodeID types.NodeID
NodeName string
TaggedAddresses map[string]string
TokenForAgent string
}
// localState is used to represent the node's services,
// and checks. We used it to perform anti-entropy with the
// catalog representation
type localState struct {
// paused is used to check if we are paused. Must be the first
// element due to a go bug.
paused int32
sync.RWMutex
logger *log.Logger
// Config is the agent config
config localStateConfig
// delegate is the consul interface to use for keeping in sync
delegate delegate
// nodeInfoInSync tracks whether the server has our correct top-level
// node information in sync
nodeInfoInSync bool
// Services tracks the local services
services map[string]*structs.NodeService
serviceStatus map[string]syncStatus
serviceTokens map[string]string
// Checks tracks the local checks
checks map[types.CheckID]*structs.HealthCheck
checkStatus map[types.CheckID]syncStatus
checkTokens map[types.CheckID]string
checkCriticalTime map[types.CheckID]time.Time
// Used to track checks that are being deferred
deferCheck map[types.CheckID]*time.Timer
// metadata tracks the local metadata fields
metadata map[string]string
// consulCh is used to inform of a change to the known
// consul nodes. This may be used to retry a sync run
consulCh chan struct{}
// triggerCh is used to inform of a change to local state
// that requires anti-entropy with the server
triggerCh chan struct{}
}
// NewLocalState creates a is used to initialize the local state
func NewLocalState(c *Config, lg *log.Logger) *localState {
lc := localStateConfig{
ACLToken: c.ACLToken,
AEInterval: c.AEInterval,
AdvertiseAddr: c.AdvertiseAddr,
CheckUpdateInterval: c.CheckUpdateInterval,
Datacenter: c.Datacenter,
NodeID: c.NodeID,
NodeName: c.NodeName,
TaggedAddresses: map[string]string{},
TokenForAgent: c.GetTokenForAgent(),
}
for k, v := range c.TaggedAddresses {
lc.TaggedAddresses[k] = v
}
return &localState{
config: lc,
logger: lg,
services: make(map[string]*structs.NodeService),
serviceStatus: make(map[string]syncStatus),
serviceTokens: make(map[string]string),
checks: make(map[types.CheckID]*structs.HealthCheck),
checkStatus: make(map[types.CheckID]syncStatus),
checkTokens: make(map[types.CheckID]string),
checkCriticalTime: make(map[types.CheckID]time.Time),
deferCheck: make(map[types.CheckID]*time.Timer),
metadata: make(map[string]string),
consulCh: make(chan struct{}, 1),
triggerCh: make(chan struct{}, 1),
}
}
// changeMade is used to trigger an anti-entropy run
func (l *localState) changeMade() {
select {
case l.triggerCh <- struct{}{}:
default:
}
}
// ConsulServerUp is used to inform that a new consul server is now
// up. This can be used to speed up the sync process if we are blocking
// waiting to discover a consul server
func (l *localState) ConsulServerUp() {
select {
case l.consulCh <- struct{}{}:
default:
}
}
// Pause is used to pause state synchronization, this can be
// used to make batch changes
func (l *localState) Pause() {
atomic.AddInt32(&l.paused, 1)
}
// Resume is used to resume state synchronization
func (l *localState) Resume() {
paused := atomic.AddInt32(&l.paused, -1)
if paused < 0 {
panic("unbalanced localState.Resume() detected")
}
l.changeMade()
}
// isPaused is used to check if we are paused
func (l *localState) isPaused() bool {
return atomic.LoadInt32(&l.paused) > 0
}
// ServiceToken returns the configured ACL token for the given
// service ID. If none is present, the agent's token is returned.
func (l *localState) ServiceToken(id string) string {
l.RLock()
defer l.RUnlock()
return l.serviceToken(id)
}
// serviceToken returns an ACL token associated with a service.
func (l *localState) serviceToken(id string) string {
token := l.serviceTokens[id]
if token == "" {
token = l.config.ACLToken
}
return token
}
// AddService is used to add a service entry to the local state.
// This entry is persistent and the agent will make a best effort to
// ensure it is registered
func (l *localState) AddService(service *structs.NodeService, token string) {
// Assign the ID if none given
if service.ID == "" && service.Service != "" {
service.ID = service.Service
}
l.Lock()
defer l.Unlock()
l.services[service.ID] = service
l.serviceStatus[service.ID] = syncStatus{}
l.serviceTokens[service.ID] = token
l.changeMade()
}
// RemoveService is used to remove a service entry from the local state.
// The agent will make a best effort to ensure it is deregistered
func (l *localState) RemoveService(serviceID string) error {
l.Lock()
defer l.Unlock()
if _, ok := l.services[serviceID]; ok {
delete(l.services, serviceID)
// Leave the service token around, if any, until we successfully
// delete the service.
l.serviceStatus[serviceID] = syncStatus{inSync: false}
l.changeMade()
} else {
return fmt.Errorf("Service does not exist")
}
return nil
}
// Services returns the locally registered services that the
// agent is aware of and are being kept in sync with the server
func (l *localState) Services() map[string]*structs.NodeService {
services := make(map[string]*structs.NodeService)
l.RLock()
defer l.RUnlock()
for name, serv := range l.services {
services[name] = serv
}
return services
}
// CheckToken is used to return the configured health check token for a
// Check, or if none is configured, the default agent ACL token.
func (l *localState) CheckToken(checkID types.CheckID) string {
l.RLock()
defer l.RUnlock()
return l.checkToken(checkID)
}
// checkToken returns an ACL token associated with a check.
func (l *localState) checkToken(checkID types.CheckID) string {
token := l.checkTokens[checkID]
if token == "" {
token = l.config.ACLToken
}
return token
}
// AddCheck is used to add a health check to the local state.
// This entry is persistent and the agent will make a best effort to
// ensure it is registered
func (l *localState) AddCheck(check *structs.HealthCheck, token string) {
// Set the node name
check.Node = l.config.NodeName
l.Lock()
defer l.Unlock()
l.checks[check.CheckID] = check
l.checkStatus[check.CheckID] = syncStatus{}
l.checkTokens[check.CheckID] = token
delete(l.checkCriticalTime, check.CheckID)
l.changeMade()
}
// RemoveCheck is used to remove a health check from the local state.
// The agent will make a best effort to ensure it is deregistered
func (l *localState) RemoveCheck(checkID types.CheckID) {
l.Lock()
defer l.Unlock()
delete(l.checks, checkID)
// Leave the check token around, if any, until we successfully delete
// the check.
delete(l.checkCriticalTime, checkID)
l.checkStatus[checkID] = syncStatus{inSync: false}
l.changeMade()
}
// UpdateCheck is used to update the status of a check
func (l *localState) UpdateCheck(checkID types.CheckID, status, output string) {
l.Lock()
defer l.Unlock()
check, ok := l.checks[checkID]
if !ok {
return
}
// Update the critical time tracking (this doesn't cause a server updates
// so we can always keep this up to date).
if status == api.HealthCritical {
_, wasCritical := l.checkCriticalTime[checkID]
if !wasCritical {
l.checkCriticalTime[checkID] = time.Now()
}
} else {
delete(l.checkCriticalTime, checkID)
}
// Do nothing if update is idempotent
if check.Status == status && check.Output == output {
return
}
// Defer a sync if the output has changed. This is an optimization around
// frequent updates of output. Instead, we update the output internally,
// and periodically do a write-back to the servers. If there is a status
// change we do the write immediately.
if l.config.CheckUpdateInterval > 0 && check.Status == status {
check.Output = output
if _, ok := l.deferCheck[checkID]; !ok {
intv := time.Duration(uint64(l.config.CheckUpdateInterval)/2) + lib.RandomStagger(l.config.CheckUpdateInterval)
deferSync := time.AfterFunc(intv, func() {
l.Lock()
if _, ok := l.checkStatus[checkID]; ok {
l.checkStatus[checkID] = syncStatus{inSync: false}
l.changeMade()
}
delete(l.deferCheck, checkID)
l.Unlock()
})
l.deferCheck[checkID] = deferSync
}
return
}
// Update status and mark out of sync
check.Status = status
check.Output = output
l.checkStatus[checkID] = syncStatus{inSync: false}
l.changeMade()
}
// Checks returns the locally registered checks that the
// agent is aware of and are being kept in sync with the server
func (l *localState) Checks() map[types.CheckID]*structs.HealthCheck {
checks := make(map[types.CheckID]*structs.HealthCheck)
l.RLock()
defer l.RUnlock()
for checkID, check := range l.checks {
checks[checkID] = check
}
return checks
}
// CriticalCheck is used to return the duration a check has been critical along
// with its associated health check.
type CriticalCheck struct {
CriticalFor time.Duration
Check *structs.HealthCheck
}
// CriticalChecks returns locally registered health checks that the agent is
// aware of and are being kept in sync with the server, and that are in a
// critical state. This also returns information about how long each check has
// been critical.
func (l *localState) CriticalChecks() map[types.CheckID]CriticalCheck {
checks := make(map[types.CheckID]CriticalCheck)
l.RLock()
defer l.RUnlock()
now := time.Now()
for checkID, criticalTime := range l.checkCriticalTime {
checks[checkID] = CriticalCheck{
CriticalFor: now.Sub(criticalTime),
Check: l.checks[checkID],
}
}
return checks
}
// Metadata returns the local node metadata fields that the
// agent is aware of and are being kept in sync with the server
func (l *localState) Metadata() map[string]string {
metadata := make(map[string]string)
l.RLock()
defer l.RUnlock()
for key, value := range l.metadata {
metadata[key] = value
}
return metadata
}
// antiEntropy is a long running method used to perform anti-entropy
// between local and remote state.
func (l *localState) antiEntropy(shutdownCh chan struct{}) {
SYNC:
// Sync our state with the servers
for {
err := l.setSyncState()
if err == nil {
break
}
l.logger.Printf("[ERR] agent: failed to sync remote state: %v", err)
select {
case <-l.consulCh:
// Stagger the retry on leader election, avoid a thundering heard
select {
case <-time.After(lib.RandomStagger(aeScale(syncStaggerIntv, len(l.delegate.LANMembers())))):
case <-shutdownCh:
return
}
case <-time.After(syncRetryIntv + lib.RandomStagger(aeScale(syncRetryIntv, len(l.delegate.LANMembers())))):
case <-shutdownCh:
return
}
}
// Force-trigger AE to pickup any changes
l.changeMade()
// Schedule the next full sync, with a random stagger
aeIntv := aeScale(l.config.AEInterval, len(l.delegate.LANMembers()))
aeIntv = aeIntv + lib.RandomStagger(aeIntv)
aeTimer := time.After(aeIntv)
// Wait for sync events
for {
select {
case <-aeTimer:
goto SYNC
case <-l.triggerCh:
// Skip the sync if we are paused
if l.isPaused() {
continue
}
if err := l.syncChanges(); err != nil {
l.logger.Printf("[ERR] agent: failed to sync changes: %v", err)
}
case <-shutdownCh:
return
}
}
}
// setSyncState does a read of the server state, and updates
// the local syncStatus as appropriate
func (l *localState) setSyncState() error {
req := structs.NodeSpecificRequest{
Datacenter: l.config.Datacenter,
Node: l.config.NodeName,
QueryOptions: structs.QueryOptions{Token: l.config.TokenForAgent},
}
var out1 structs.IndexedNodeServices
var out2 structs.IndexedHealthChecks
if e := l.delegate.RPC("Catalog.NodeServices", &req, &out1); e != nil {
return e
}
if err := l.delegate.RPC("Health.NodeChecks", &req, &out2); err != nil {
return err
}
checks := out2.HealthChecks
l.Lock()
defer l.Unlock()
// Check the node info
if out1.NodeServices == nil || out1.NodeServices.Node == nil ||
out1.NodeServices.Node.ID != l.config.NodeID ||
!reflect.DeepEqual(out1.NodeServices.Node.TaggedAddresses, l.config.TaggedAddresses) ||
!reflect.DeepEqual(out1.NodeServices.Node.Meta, l.metadata) {
l.nodeInfoInSync = false
}
// Check all our services
services := make(map[string]*structs.NodeService)
if out1.NodeServices != nil {
services = out1.NodeServices.Services
}
for id := range l.services {
// If the local service doesn't exist remotely, then sync it
if _, ok := services[id]; !ok {
l.serviceStatus[id] = syncStatus{inSync: false}
}
}
for id, service := range services {
// If we don't have the service locally, deregister it
existing, ok := l.services[id]
if !ok {
// The consul service is created automatically, and does
// not need to be deregistered.
if id == structs.ConsulServiceID {
continue
}
l.serviceStatus[id] = syncStatus{inSync: false}
continue
}
// If our definition is different, we need to update it. Make a
// copy so that we don't retain a pointer to any actual state
// store info for in-memory RPCs.
if existing.EnableTagOverride {
existing.Tags = make([]string, len(service.Tags))
copy(existing.Tags, service.Tags)
}
equal := existing.IsSame(service)
l.serviceStatus[id] = syncStatus{inSync: equal}
}
// Index the remote health checks to improve efficiency
checkIndex := make(map[types.CheckID]*structs.HealthCheck, len(checks))
for _, check := range checks {
checkIndex[check.CheckID] = check
}
// Sync any check which doesn't exist on the remote side
for id := range l.checks {
if _, ok := checkIndex[id]; !ok {
l.checkStatus[id] = syncStatus{inSync: false}
}
}
for _, check := range checks {
// If we don't have the check locally, deregister it
id := check.CheckID
existing, ok := l.checks[id]
if !ok {
// The Serf check is created automatically, and does not
// need to be deregistered.
if id == structs.SerfCheckID {
continue
}
l.checkStatus[id] = syncStatus{inSync: false}
continue
}
// If our definition is different, we need to update it
var equal bool
if l.config.CheckUpdateInterval == 0 {
equal = existing.IsSame(check)
} else {
// Copy the existing check before potentially modifying
// it before the compare operation.
eCopy := existing.Clone()
// Copy the server's check before modifying, otherwise
// in-memory RPCs will have side effects.
cCopy := check.Clone()
// If there's a defer timer active then we've got a
// potentially spammy check so we don't sync the output
// during this sweep since the timer will mark the check
// out of sync for us. Otherwise, it is safe to sync the
// output now. This is especially important for checks
// that don't change state after they are created, in
// which case we'd never see their output synced back ever.
if _, ok := l.deferCheck[id]; ok {
eCopy.Output = ""
cCopy.Output = ""
}
equal = eCopy.IsSame(cCopy)
}
// Update the status
l.checkStatus[id] = syncStatus{inSync: equal}
}
return nil
}
// syncChanges is used to scan the status our local services and checks
// and update any that are out of sync with the server
func (l *localState) syncChanges() error {
l.Lock()
defer l.Unlock()
// We will do node-level info syncing at the end, since it will get
// updated by a service or check sync anyway, given how the register
// API works.
// Sync the services
for id, status := range l.serviceStatus {
if _, ok := l.services[id]; !ok {
if err := l.deleteService(id); err != nil {
return err
}
} else if !status.inSync {
if err := l.syncService(id); err != nil {
return err
}
} else {
l.logger.Printf("[DEBUG] agent: Service '%s' in sync", id)
}
}
// Sync the checks
for id, status := range l.checkStatus {
if _, ok := l.checks[id]; !ok {
if err := l.deleteCheck(id); err != nil {
return err
}
} else if !status.inSync {
// Cancel a deferred sync
if timer := l.deferCheck[id]; timer != nil {
timer.Stop()
delete(l.deferCheck, id)
}
if err := l.syncCheck(id); err != nil {
return err
}
} else {
l.logger.Printf("[DEBUG] agent: Check '%s' in sync", id)
}
}
// Now sync the node level info if we need to, and didn't do any of
// the other sync operations.
if !l.nodeInfoInSync {
if err := l.syncNodeInfo(); err != nil {
return err
}
} else {
l.logger.Printf("[DEBUG] agent: Node info in sync")
}
return nil
}
// deleteService is used to delete a service from the server
func (l *localState) deleteService(id string) error {
if id == "" {
return fmt.Errorf("ServiceID missing")
}
req := structs.DeregisterRequest{
Datacenter: l.config.Datacenter,
Node: l.config.NodeName,
ServiceID: id,
WriteRequest: structs.WriteRequest{Token: l.serviceToken(id)},
}
var out struct{}
err := l.delegate.RPC("Catalog.Deregister", &req, &out)
if err == nil || strings.Contains(err.Error(), "Unknown service") {
delete(l.serviceStatus, id)
delete(l.serviceTokens, id)
l.logger.Printf("[INFO] agent: Deregistered service '%s'", id)
return nil
} else if strings.Contains(err.Error(), permissionDenied) {
l.serviceStatus[id] = syncStatus{inSync: true}
l.logger.Printf("[WARN] agent: Service '%s' deregistration blocked by ACLs", id)
return nil
}
return err
}
// deleteCheck is used to delete a check from the server
func (l *localState) deleteCheck(id types.CheckID) error {
if id == "" {
return fmt.Errorf("CheckID missing")
}
req := structs.DeregisterRequest{
Datacenter: l.config.Datacenter,
Node: l.config.NodeName,
CheckID: id,
WriteRequest: structs.WriteRequest{Token: l.checkToken(id)},
}
var out struct{}
err := l.delegate.RPC("Catalog.Deregister", &req, &out)
if err == nil || strings.Contains(err.Error(), "Unknown check") {
delete(l.checkStatus, id)
delete(l.checkTokens, id)
l.logger.Printf("[INFO] agent: Deregistered check '%s'", id)
return nil
} else if strings.Contains(err.Error(), permissionDenied) {
l.checkStatus[id] = syncStatus{inSync: true}
l.logger.Printf("[WARN] agent: Check '%s' deregistration blocked by ACLs", id)
return nil
}
return err
}
// syncService is used to sync a service to the server
func (l *localState) syncService(id string) error {
req := structs.RegisterRequest{
Datacenter: l.config.Datacenter,
ID: l.config.NodeID,
Node: l.config.NodeName,
Address: l.config.AdvertiseAddr,
TaggedAddresses: l.config.TaggedAddresses,
NodeMeta: l.metadata,
Service: l.services[id],
WriteRequest: structs.WriteRequest{Token: l.serviceToken(id)},
}
// If the service has associated checks that are out of sync,
// piggyback them on the service sync so they are part of the
// same transaction and are registered atomically. We only let
// checks ride on service registrations with the same token,
// otherwise we need to register them separately so they don't
// pick up privileges from the service token.
var checks structs.HealthChecks
for _, check := range l.checks {
if check.ServiceID == id && (l.serviceToken(id) == l.checkToken(check.CheckID)) {
if stat, ok := l.checkStatus[check.CheckID]; !ok || !stat.inSync {
checks = append(checks, check)
}
}
}
// Backwards-compatibility for Consul < 0.5
if len(checks) == 1 {
req.Check = checks[0]
} else {
req.Checks = checks
}
var out struct{}
err := l.delegate.RPC("Catalog.Register", &req, &out)
if err == nil {
l.serviceStatus[id] = syncStatus{inSync: true}
// Given how the register API works, this info is also updated
// every time we sync a service.
l.nodeInfoInSync = true
l.logger.Printf("[INFO] agent: Synced service '%s'", id)
for _, check := range checks {
l.checkStatus[check.CheckID] = syncStatus{inSync: true}
}
} else if strings.Contains(err.Error(), permissionDenied) {
l.serviceStatus[id] = syncStatus{inSync: true}
l.logger.Printf("[WARN] agent: Service '%s' registration blocked by ACLs", id)
for _, check := range checks {
l.checkStatus[check.CheckID] = syncStatus{inSync: true}
}
return nil
}
return err
}
// syncCheck is used to sync a check to the server
func (l *localState) syncCheck(id types.CheckID) error {
// Pull in the associated service if any
check := l.checks[id]
var service *structs.NodeService
if check.ServiceID != "" {
if serv, ok := l.services[check.ServiceID]; ok {
service = serv
}
}
req := structs.RegisterRequest{
Datacenter: l.config.Datacenter,
ID: l.config.NodeID,
Node: l.config.NodeName,
Address: l.config.AdvertiseAddr,
TaggedAddresses: l.config.TaggedAddresses,
NodeMeta: l.metadata,
Service: service,
Check: l.checks[id],
WriteRequest: structs.WriteRequest{Token: l.checkToken(id)},
}
var out struct{}
err := l.delegate.RPC("Catalog.Register", &req, &out)
if err == nil {
l.checkStatus[id] = syncStatus{inSync: true}
// Given how the register API works, this info is also updated
// every time we sync a check.
l.nodeInfoInSync = true
l.logger.Printf("[INFO] agent: Synced check '%s'", id)
} else if strings.Contains(err.Error(), permissionDenied) {
l.checkStatus[id] = syncStatus{inSync: true}
l.logger.Printf("[WARN] agent: Check '%s' registration blocked by ACLs", id)
return nil
}
return err
}
func (l *localState) syncNodeInfo() error {
req := structs.RegisterRequest{
Datacenter: l.config.Datacenter,
ID: l.config.NodeID,
Node: l.config.NodeName,
Address: l.config.AdvertiseAddr,
TaggedAddresses: l.config.TaggedAddresses,
NodeMeta: l.metadata,
WriteRequest: structs.WriteRequest{Token: l.config.TokenForAgent},
}
var out struct{}
err := l.delegate.RPC("Catalog.Register", &req, &out)
if err == nil {
l.nodeInfoInSync = true
l.logger.Printf("[INFO] agent: Synced node info")
} else if strings.Contains(err.Error(), permissionDenied) {
l.nodeInfoInSync = true
l.logger.Printf("[WARN] agent: Node info update blocked by ACLs")
return nil
}
return err
}