mirror of https://github.com/hashicorp/consul
461 lines
15 KiB
Go
461 lines
15 KiB
Go
package agent
|
|
|
|
import (
|
|
"fmt"
|
|
"sync"
|
|
|
|
"github.com/imdario/mergo"
|
|
"github.com/mitchellh/copystructure"
|
|
"golang.org/x/net/context"
|
|
|
|
"github.com/hashicorp/consul/agent/cache"
|
|
cachetype "github.com/hashicorp/consul/agent/cache-types"
|
|
"github.com/hashicorp/consul/agent/structs"
|
|
)
|
|
|
|
// ServiceManager watches changes to central service config for all services
|
|
// registered with it. When a central config changes, the local service will
|
|
// be updated with the correct values from the central config.
|
|
type ServiceManager struct {
|
|
agent *Agent
|
|
|
|
// servicesLock guards the services map, but not the watches contained
|
|
// therein
|
|
servicesLock sync.Mutex
|
|
|
|
// services tracks all active watches for registered services
|
|
services map[structs.ServiceID]*serviceConfigWatch
|
|
|
|
// ctx is the shared context for all goroutines launched
|
|
ctx context.Context
|
|
|
|
// cancel can be used to stop all goroutines launched
|
|
cancel context.CancelFunc
|
|
|
|
// running keeps track of live goroutines (worker and watcher)
|
|
running sync.WaitGroup
|
|
}
|
|
|
|
func NewServiceManager(agent *Agent) *ServiceManager {
|
|
ctx, cancel := context.WithCancel(context.Background())
|
|
return &ServiceManager{
|
|
agent: agent,
|
|
services: make(map[structs.ServiceID]*serviceConfigWatch),
|
|
ctx: ctx,
|
|
cancel: cancel,
|
|
}
|
|
}
|
|
|
|
// Stop forces all background goroutines to terminate and blocks until they complete.
|
|
//
|
|
// NOTE: the caller must NOT hold the Agent.stateLock!
|
|
func (s *ServiceManager) Stop() {
|
|
s.cancel()
|
|
s.running.Wait()
|
|
}
|
|
|
|
// AddService will (re)create a serviceConfigWatch on the given service. For
|
|
// each call of this function the first registration will happen inline and
|
|
// will read the merged global defaults for the service through the agent cache
|
|
// (regardless of whether or not the service was already registered). This
|
|
// lets validation or authorization related errors bubble back up to the
|
|
// caller's RPC inline with their request. Upon success a goroutine will keep
|
|
// this updated in the background.
|
|
//
|
|
// If waitForCentralConfig=true is used, the initial registration blocks on
|
|
// fetching the merged global config through the cache. If false, no such RPC
|
|
// occurs and only the previousDefaults are used.
|
|
//
|
|
// persistServiceConfig controls if the INITIAL registration will result in
|
|
// persisting the service config to disk again. All background updates will
|
|
// always persist.
|
|
//
|
|
// service, chkTypes, persist, token, replaceExistingChecks, and source are
|
|
// basically pass-through arguments to Agent.addServiceInternal that follow the
|
|
// semantics there. The one key difference is that the service provided will be
|
|
// merged with the global defaults before registration.
|
|
//
|
|
// NOTE: the caller must hold the Agent.stateLock!
|
|
func (s *ServiceManager) AddService(req addServiceLockedRequest) error {
|
|
s.servicesLock.Lock()
|
|
defer s.servicesLock.Unlock()
|
|
|
|
sid := req.Service.CompoundServiceID()
|
|
|
|
// If a service watch already exists, shut it down and replace it.
|
|
oldWatch, updating := s.services[sid]
|
|
if updating {
|
|
oldWatch.Stop()
|
|
delete(s.services, sid)
|
|
}
|
|
|
|
// Get the existing global config and do the initial registration with the
|
|
// merged config.
|
|
watch := &serviceConfigWatch{registration: req, agent: s.agent}
|
|
if err := watch.register(s.ctx); err != nil {
|
|
return err
|
|
}
|
|
if err := watch.start(s.ctx, &s.running); err != nil {
|
|
return err
|
|
}
|
|
|
|
s.services[sid] = watch
|
|
|
|
if updating {
|
|
s.agent.logger.Debug("updated local registration for service", "service", req.Service.ID)
|
|
} else {
|
|
s.agent.logger.Debug("added local registration for service", "service", req.Service.ID)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// NOTE: the caller must hold the Agent.stateLock!
|
|
func (s *ServiceManager) RemoveService(serviceID structs.ServiceID) {
|
|
s.servicesLock.Lock()
|
|
defer s.servicesLock.Unlock()
|
|
|
|
if oldWatch, exists := s.services[serviceID]; exists {
|
|
oldWatch.Stop()
|
|
delete(s.services, serviceID)
|
|
}
|
|
}
|
|
|
|
// serviceConfigWatch is a long running helper for composing the end config
|
|
// for a given service from both the local registration and the global
|
|
// service/proxy defaults.
|
|
type serviceConfigWatch struct {
|
|
registration addServiceLockedRequest
|
|
agent *Agent
|
|
|
|
// cacheKey stores the key of the current request, when registration changes
|
|
// we check to see if a new cache watch is needed.
|
|
cacheKey string
|
|
|
|
cancelFunc func()
|
|
running sync.WaitGroup
|
|
}
|
|
|
|
// NOTE: this is called while holding the Agent.stateLock
|
|
func (w *serviceConfigWatch) register(ctx context.Context) error {
|
|
serviceDefaults, err := w.registration.serviceDefaults(ctx)
|
|
if err != nil {
|
|
return fmt.Errorf("could not retrieve initial service_defaults config for service %q: %v",
|
|
w.registration.Service.ID, err)
|
|
}
|
|
|
|
// Merge the local registration with the central defaults and update this service
|
|
// in the local state.
|
|
merged, err := mergeServiceConfig(serviceDefaults, w.registration.Service)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// make a copy of the AddServiceRequest
|
|
req := w.registration
|
|
req.Service = merged
|
|
|
|
err = w.agent.addServiceInternal(addServiceInternalRequest{
|
|
addServiceLockedRequest: req,
|
|
persistService: w.registration.Service,
|
|
persistServiceDefaults: serviceDefaults,
|
|
})
|
|
if err != nil {
|
|
return fmt.Errorf("error updating service registration: %v", err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func serviceDefaultsFromStruct(v *structs.ServiceConfigResponse) func(context.Context) (*structs.ServiceConfigResponse, error) {
|
|
return func(_ context.Context) (*structs.ServiceConfigResponse, error) {
|
|
return v, nil
|
|
}
|
|
}
|
|
|
|
func serviceDefaultsFromCache(bd BaseDeps, req AddServiceRequest) func(context.Context) (*structs.ServiceConfigResponse, error) {
|
|
// NOTE: this is called while holding the Agent.stateLock
|
|
return func(ctx context.Context) (*structs.ServiceConfigResponse, error) {
|
|
req := makeConfigRequest(bd, req)
|
|
|
|
raw, _, err := bd.Cache.Get(ctx, cachetype.ResolvedServiceConfigName, req)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
serviceConfig, ok := raw.(*structs.ServiceConfigResponse)
|
|
if !ok {
|
|
// This should never happen, but we want to protect against panics
|
|
return nil, fmt.Errorf("internal error: response type not correct")
|
|
}
|
|
return serviceConfig, nil
|
|
}
|
|
}
|
|
|
|
// Start starts the config watch and a goroutine to handle updates over the
|
|
// updateCh. This is safe to call more than once assuming you have called Stop
|
|
// after each Start.
|
|
//
|
|
// NOTE: this is called while holding the Agent.stateLock
|
|
func (w *serviceConfigWatch) start(ctx context.Context, wg *sync.WaitGroup) error {
|
|
ctx, w.cancelFunc = context.WithCancel(ctx)
|
|
|
|
// Configure and start a cache.Notify goroutine to run a continuous
|
|
// blocking query on the resolved service config for this service.
|
|
req := makeConfigRequest(w.agent.baseDeps, w.registration.AddServiceRequest)
|
|
w.cacheKey = req.CacheInfo().Key
|
|
|
|
updateCh := make(chan cache.UpdateEvent, 1)
|
|
|
|
// We use the cache key as the correlationID here. Notify in general will not
|
|
// respond on the updateCh after the context is cancelled however there could
|
|
// possible be a race where it has only just got an update and checked the
|
|
// context before we cancel and so might still deliver the old event. Using
|
|
// the cacheKey allows us to ignore updates from the old cache watch and makes
|
|
// even this rare edge case safe.
|
|
err := w.agent.cache.Notify(ctx, cachetype.ResolvedServiceConfigName, req, w.cacheKey, updateCh)
|
|
if err != nil {
|
|
w.cancelFunc()
|
|
return err
|
|
}
|
|
|
|
w.running.Add(1)
|
|
wg.Add(1)
|
|
go w.runWatch(ctx, wg, updateCh)
|
|
|
|
return nil
|
|
}
|
|
|
|
func (w *serviceConfigWatch) Stop() {
|
|
w.cancelFunc()
|
|
w.running.Wait()
|
|
}
|
|
|
|
// runWatch handles any update events from the cache.Notify until the
|
|
// config watch is shut down.
|
|
//
|
|
// NOTE: the caller must NOT hold the Agent.stateLock!
|
|
func (w *serviceConfigWatch) runWatch(ctx context.Context, wg *sync.WaitGroup, updateCh chan cache.UpdateEvent) {
|
|
defer wg.Done()
|
|
defer w.running.Done()
|
|
|
|
for {
|
|
select {
|
|
case <-ctx.Done():
|
|
return
|
|
case event := <-updateCh:
|
|
if err := w.handleUpdate(ctx, event); err != nil {
|
|
w.agent.logger.Error("error handling service update", "error", err)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// handleUpdate receives an update event from the global config defaults, updates
|
|
// the local state and re-registers the service with the newly merged config.
|
|
//
|
|
// NOTE: the caller must NOT hold the Agent.stateLock!
|
|
func (w *serviceConfigWatch) handleUpdate(ctx context.Context, event cache.UpdateEvent) error {
|
|
// If we got an error, log a warning if this is the first update; otherwise return the error.
|
|
// We want the initial update to cause a service registration no matter what.
|
|
if event.Err != nil {
|
|
return fmt.Errorf("error watching service config: %v", event.Err)
|
|
}
|
|
|
|
serviceDefaults, ok := event.Result.(*structs.ServiceConfigResponse)
|
|
if !ok {
|
|
return fmt.Errorf("unknown update event type: %T", event)
|
|
}
|
|
|
|
// Sanity check this even came from the currently active watch to ignore
|
|
// rare races when switching cache keys
|
|
if event.CorrelationID != w.cacheKey {
|
|
// It's a no-op. The new watcher will deliver (or may have already
|
|
// delivered) the correct config so just ignore this old message.
|
|
return nil
|
|
}
|
|
|
|
// Merge the local registration with the central defaults and update this service
|
|
// in the local state.
|
|
merged, err := mergeServiceConfig(serviceDefaults, w.registration.Service)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// make a copy of the AddServiceRequest
|
|
req := w.registration
|
|
req.Service = merged
|
|
req.persistServiceConfig = true
|
|
|
|
args := addServiceInternalRequest{
|
|
addServiceLockedRequest: req,
|
|
persistService: w.registration.Service,
|
|
persistServiceDefaults: serviceDefaults,
|
|
}
|
|
|
|
if err := w.agent.stateLock.TryLock(ctx); err != nil {
|
|
return nil
|
|
}
|
|
defer w.agent.stateLock.Unlock()
|
|
|
|
// The context may have been cancelled after the lock was acquired.
|
|
if err := ctx.Err(); err != nil {
|
|
return nil
|
|
}
|
|
|
|
if err := w.agent.addServiceInternal(args); err != nil {
|
|
return fmt.Errorf("error updating service registration: %v", err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func makeConfigRequest(bd BaseDeps, addReq AddServiceRequest) *structs.ServiceConfigRequest {
|
|
var (
|
|
ns = addReq.Service
|
|
name = ns.Service
|
|
)
|
|
|
|
var upstreams []structs.ServiceID
|
|
|
|
// Note that only sidecar proxies should even make it here for now although
|
|
// later that will change to add the condition.
|
|
if ns.IsSidecarProxy() {
|
|
// This is a sidecar proxy, ignore the proxy service's config since we are
|
|
// managed by the target service config.
|
|
name = ns.Proxy.DestinationServiceName
|
|
|
|
// Also if we have any upstreams defined, add them to the request so we can
|
|
// learn about their configs.
|
|
for _, us := range ns.Proxy.Upstreams {
|
|
if us.DestinationType == "" || us.DestinationType == structs.UpstreamDestTypeService {
|
|
sid := us.DestinationID()
|
|
sid.EnterpriseMeta.Merge(&ns.EnterpriseMeta)
|
|
upstreams = append(upstreams, sid)
|
|
}
|
|
}
|
|
}
|
|
|
|
req := &structs.ServiceConfigRequest{
|
|
Name: name,
|
|
Datacenter: bd.RuntimeConfig.Datacenter,
|
|
QueryOptions: structs.QueryOptions{Token: addReq.token},
|
|
MeshGateway: ns.Proxy.MeshGateway,
|
|
Mode: ns.Proxy.Mode,
|
|
UpstreamIDs: upstreams,
|
|
EnterpriseMeta: ns.EnterpriseMeta,
|
|
}
|
|
if req.QueryOptions.Token == "" {
|
|
req.QueryOptions.Token = bd.Tokens.AgentToken()
|
|
}
|
|
return req
|
|
}
|
|
|
|
// mergeServiceConfig from service into defaults to produce the final effective
|
|
// config for the watched service.
|
|
func mergeServiceConfig(defaults *structs.ServiceConfigResponse, service *structs.NodeService) (*structs.NodeService, error) {
|
|
if defaults == nil {
|
|
return service, nil
|
|
}
|
|
|
|
// We don't want to change s.registration in place since it is our source of
|
|
// truth about what was actually registered before defaults applied. So copy
|
|
// it first.
|
|
nsRaw, err := copystructure.Copy(service)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Merge proxy defaults
|
|
ns := nsRaw.(*structs.NodeService)
|
|
|
|
if err := mergo.Merge(&ns.Proxy.Config, defaults.ProxyConfig); err != nil {
|
|
return nil, err
|
|
}
|
|
if err := mergo.Merge(&ns.Proxy.Expose, defaults.Expose); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if ns.Proxy.MeshGateway.Mode == structs.MeshGatewayModeDefault {
|
|
ns.Proxy.MeshGateway.Mode = defaults.MeshGateway.Mode
|
|
}
|
|
if ns.Proxy.Mode == structs.ProxyModeDefault {
|
|
ns.Proxy.Mode = defaults.Mode
|
|
}
|
|
if ns.Proxy.TransparentProxy.OutboundListenerPort == 0 {
|
|
ns.Proxy.TransparentProxy.OutboundListenerPort = defaults.TransparentProxy.OutboundListenerPort
|
|
}
|
|
if !ns.Proxy.TransparentProxy.DialedDirectly {
|
|
ns.Proxy.TransparentProxy.DialedDirectly = defaults.TransparentProxy.DialedDirectly
|
|
}
|
|
|
|
// remoteUpstreams contains synthetic Upstreams generated from central config (service-defaults.UpstreamConfigs).
|
|
remoteUpstreams := make(map[structs.ServiceID]structs.Upstream)
|
|
|
|
for _, us := range defaults.UpstreamIDConfigs {
|
|
parsed, err := structs.ParseUpstreamConfigNoDefaults(us.Config)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to parse upstream config map for %s: %v", us.Upstream.String(), err)
|
|
}
|
|
|
|
remoteUpstreams[us.Upstream] = structs.Upstream{
|
|
DestinationNamespace: us.Upstream.NamespaceOrDefault(),
|
|
DestinationName: us.Upstream.ID,
|
|
Config: us.Config,
|
|
MeshGateway: parsed.MeshGateway,
|
|
CentrallyConfigured: true,
|
|
}
|
|
}
|
|
|
|
// localUpstreams stores the upstreams seen from the local registration so that we can merge in the synthetic entries.
|
|
// In transparent proxy mode ns.Proxy.Upstreams will likely be empty because users do not need to define upstreams explicitly.
|
|
// So to store upstream-specific flags from central config, we add entries to ns.Proxy.Upstream with those values.
|
|
localUpstreams := make(map[structs.ServiceID]struct{})
|
|
|
|
// Merge upstream defaults into the local registration
|
|
for i := range ns.Proxy.Upstreams {
|
|
// Get a pointer not a value copy of the upstream struct
|
|
us := &ns.Proxy.Upstreams[i]
|
|
if us.DestinationType != "" && us.DestinationType != structs.UpstreamDestTypeService {
|
|
continue
|
|
}
|
|
localUpstreams[us.DestinationID()] = struct{}{}
|
|
|
|
remoteCfg, ok := remoteUpstreams[us.DestinationID()]
|
|
if !ok {
|
|
// No config defaults to merge
|
|
continue
|
|
}
|
|
|
|
// The local upstream config mode has the highest precedence, so only overwrite when it's set to the default
|
|
if us.MeshGateway.Mode == structs.MeshGatewayModeDefault {
|
|
us.MeshGateway.Mode = remoteCfg.MeshGateway.Mode
|
|
}
|
|
|
|
// Merge in everything else that is read from the map
|
|
if err := mergo.Merge(&us.Config, remoteCfg.Config); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Delete the mesh gateway key from opaque config since this is the value that was resolved from
|
|
// the servers and NOT the final merged value for this upstream.
|
|
// Note that we use the "mesh_gateway" key and not other variants like "MeshGateway" because
|
|
// UpstreamConfig.MergeInto and ResolveServiceConfig only use "mesh_gateway".
|
|
delete(us.Config, "mesh_gateway")
|
|
}
|
|
|
|
// Ensure upstreams present in central config are represented in the local configuration.
|
|
// This does not apply outside of transparent mode because in that situation every possible upstream already exists
|
|
// inside of ns.Proxy.Upstreams.
|
|
if ns.Proxy.Mode == structs.ProxyModeTransparent {
|
|
for id, remote := range remoteUpstreams {
|
|
if _, ok := localUpstreams[id]; ok {
|
|
// Remote upstream is already present locally
|
|
continue
|
|
}
|
|
|
|
ns.Proxy.Upstreams = append(ns.Proxy.Upstreams, remote)
|
|
}
|
|
}
|
|
|
|
return ns, err
|
|
}
|