micro/registry/memory/memory.go
Asim Aslam 563768b58a
v3 refactor (#1868)
* Move to v3

Co-authored-by: Ben Toogood <bentoogood@gmail.com>
2020-07-27 13:22:00 +01:00

451 lines
10 KiB
Go

// Package memory provides an in-memory registry
package memory
import (
"context"
"sync"
"time"
"github.com/google/uuid"
"github.com/micro/go-micro/v3/logger"
"github.com/micro/go-micro/v3/registry"
)
var (
sendEventTime = 10 * time.Millisecond
ttlPruneTime = time.Second
)
type node struct {
*registry.Node
TTL time.Duration
LastSeen time.Time
}
type record struct {
Name string
Version string
Metadata map[string]string
Nodes map[string]*node
Endpoints []*registry.Endpoint
}
type Registry struct {
options registry.Options
sync.RWMutex
// records is a KV map with domain name as the key and a services map as the value
records map[string]services
watchers map[string]*Watcher
}
// services is a KV map with service name as the key and a map of records as the value
type services map[string]map[string]*record
// NewRegistry returns an initialized in-memory registry
func NewRegistry(opts ...registry.Option) registry.Registry {
options := registry.Options{
Context: context.Background(),
}
for _, o := range opts {
o(&options)
}
// records can be passed for testing purposes
records := getServiceRecords(options.Context)
if records == nil {
records = make(services)
}
reg := &Registry{
options: options,
records: map[string]services{registry.DefaultDomain: records},
watchers: make(map[string]*Watcher),
}
go reg.ttlPrune()
return reg
}
func (m *Registry) ttlPrune() {
prune := time.NewTicker(ttlPruneTime)
defer prune.Stop()
for {
select {
case <-prune.C:
m.Lock()
for domain, services := range m.records {
for service, versions := range services {
for version, record := range versions {
for id, n := range record.Nodes {
if n.TTL != 0 && time.Since(n.LastSeen) > n.TTL {
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Registry TTL expired for node %s of service %s", n.Id, service)
}
delete(m.records[domain][service][version].Nodes, id)
}
}
}
}
}
m.Unlock()
}
}
}
func (m *Registry) sendEvent(r *registry.Result) {
m.RLock()
watchers := make([]*Watcher, 0, len(m.watchers))
for _, w := range m.watchers {
watchers = append(watchers, w)
}
m.RUnlock()
for _, w := range watchers {
select {
case <-w.exit:
m.Lock()
delete(m.watchers, w.id)
m.Unlock()
default:
select {
case w.res <- r:
case <-time.After(sendEventTime):
}
}
}
}
func (m *Registry) Init(opts ...registry.Option) error {
for _, o := range opts {
o(&m.options)
}
// add services
m.Lock()
defer m.Unlock()
// get the existing services from the records
srvs, ok := m.records[registry.DefaultDomain]
if !ok {
srvs = make(services)
}
// loop through the services and if it doesn't yet exist, add it to the slice. This is used for
// testing purposes.
for name, record := range getServiceRecords(m.options.Context) {
if _, ok := srvs[name]; !ok {
srvs[name] = record
continue
}
for version, r := range record {
if _, ok := srvs[name][version]; !ok {
srvs[name][version] = r
continue
}
}
}
// set the services in the registry
m.records[registry.DefaultDomain] = srvs
return nil
}
func (m *Registry) Options() registry.Options {
return m.options
}
func (m *Registry) Register(s *registry.Service, opts ...registry.RegisterOption) error {
m.Lock()
defer m.Unlock()
// parse the options, fallback to the default domain
var options registry.RegisterOptions
for _, o := range opts {
o(&options)
}
if len(options.Domain) == 0 {
options.Domain = registry.DefaultDomain
}
// get the services for this domain from the registry
srvs, ok := m.records[options.Domain]
if !ok {
srvs = make(services)
}
// domain is set in metadata so it can be passed to watchers
if s.Metadata == nil {
s.Metadata = map[string]string{"domain": options.Domain}
} else {
s.Metadata["domain"] = options.Domain
}
// ensure the service name exists
r := serviceToRecord(s, options.TTL)
if _, ok := srvs[s.Name]; !ok {
srvs[s.Name] = make(map[string]*record)
}
if _, ok := srvs[s.Name][s.Version]; !ok {
srvs[s.Name][s.Version] = r
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Registry added new service: %s, version: %s", s.Name, s.Version)
}
m.records[options.Domain] = srvs
go m.sendEvent(&registry.Result{Action: "create", Service: s})
}
addedNodes := false
for _, n := range s.Nodes {
if _, ok := srvs[s.Name][s.Version].Nodes[n.Id]; !ok {
addedNodes = true
metadata := make(map[string]string)
for k, v := range n.Metadata {
metadata[k] = v
srvs[s.Name][s.Version].Nodes[n.Id] = &node{
Node: &registry.Node{
Id: n.Id,
Address: n.Address,
Metadata: metadata,
},
TTL: options.TTL,
LastSeen: time.Now(),
}
}
}
}
if addedNodes {
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Registry added new node to service: %s, version: %s", s.Name, s.Version)
}
go m.sendEvent(&registry.Result{Action: "update", Service: s})
} else {
// refresh TTL and timestamp
for _, n := range s.Nodes {
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Updated registration for service: %s, version: %s", s.Name, s.Version)
}
srvs[s.Name][s.Version].Nodes[n.Id].TTL = options.TTL
srvs[s.Name][s.Version].Nodes[n.Id].LastSeen = time.Now()
}
}
m.records[options.Domain] = srvs
return nil
}
func (m *Registry) Deregister(s *registry.Service, opts ...registry.DeregisterOption) error {
m.Lock()
defer m.Unlock()
// parse the options, fallback to the default domain
var options registry.DeregisterOptions
for _, o := range opts {
o(&options)
}
if len(options.Domain) == 0 {
options.Domain = registry.DefaultDomain
}
// domain is set in metadata so it can be passed to watchers
if s.Metadata == nil {
s.Metadata = map[string]string{"domain": options.Domain}
} else {
s.Metadata["domain"] = options.Domain
}
// if the domain doesn't exist, there is nothing to deregister
services, ok := m.records[options.Domain]
if !ok {
return nil
}
// if no services with this name and version exist, there is nothing to deregister
versions, ok := services[s.Name]
if !ok {
return nil
}
version, ok := versions[s.Version]
if !ok {
return nil
}
// deregister all of the service nodes from this version
for _, n := range s.Nodes {
if _, ok := version.Nodes[n.Id]; ok {
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Registry removed node from service: %s, version: %s", s.Name, s.Version)
}
delete(version.Nodes, n.Id)
}
}
// if the nodes not empty, we replace the version in the store and exist, the rest of the logic
// is cleanup
if len(version.Nodes) > 0 {
m.records[options.Domain][s.Name][s.Version] = version
go m.sendEvent(&registry.Result{Action: "update", Service: s})
return nil
}
// if this version was the only version of the service, we can remove the whole service from the
// registry and exit
if len(versions) == 1 {
delete(m.records[options.Domain], s.Name)
go m.sendEvent(&registry.Result{Action: "delete", Service: s})
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Registry removed service: %s", s.Name)
}
return nil
}
// there are other versions of the service running, so only remove this version of it
delete(m.records[options.Domain][s.Name], s.Version)
go m.sendEvent(&registry.Result{Action: "delete", Service: s})
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("Registry removed service: %s, version: %s", s.Name, s.Version)
}
return nil
}
func (m *Registry) GetService(name string, opts ...registry.GetOption) ([]*registry.Service, error) {
// parse the options, fallback to the default domain
var options registry.GetOptions
for _, o := range opts {
o(&options)
}
if len(options.Domain) == 0 {
options.Domain = registry.DefaultDomain
}
// if it's a wildcard domain, return from all domains
if options.Domain == registry.WildcardDomain {
m.RLock()
recs := m.records
m.RUnlock()
var services []*registry.Service
for domain := range recs {
srvs, err := m.GetService(name, append(opts, registry.GetDomain(domain))...)
if err == registry.ErrNotFound {
continue
} else if err != nil {
return nil, err
}
services = append(services, srvs...)
}
if len(services) == 0 {
return nil, registry.ErrNotFound
}
return services, nil
}
m.RLock()
defer m.RUnlock()
// check the domain exists
services, ok := m.records[options.Domain]
if !ok {
return nil, registry.ErrNotFound
}
// check the service exists
versions, ok := services[name]
if !ok || len(versions) == 0 {
return nil, registry.ErrNotFound
}
// serialize the response
result := make([]*registry.Service, len(versions))
i := 0
for _, r := range versions {
result[i] = recordToService(r, options.Domain)
i++
}
return result, nil
}
func (m *Registry) ListServices(opts ...registry.ListOption) ([]*registry.Service, error) {
// parse the options, fallback to the default domain
var options registry.ListOptions
for _, o := range opts {
o(&options)
}
if len(options.Domain) == 0 {
options.Domain = registry.DefaultDomain
}
// if it's a wildcard domain, list from all domains
if options.Domain == registry.WildcardDomain {
m.RLock()
recs := m.records
m.RUnlock()
var services []*registry.Service
for domain := range recs {
srvs, err := m.ListServices(append(opts, registry.ListDomain(domain))...)
if err != nil {
return nil, err
}
services = append(services, srvs...)
}
return services, nil
}
m.RLock()
defer m.RUnlock()
// ensure the domain exists
services, ok := m.records[options.Domain]
if !ok {
return make([]*registry.Service, 0), nil
}
// serialize the result, each version counts as an individual service
var result []*registry.Service
for domain, service := range services {
for _, version := range service {
result = append(result, recordToService(version, domain))
}
}
return result, nil
}
func (m *Registry) Watch(opts ...registry.WatchOption) (registry.Watcher, error) {
// parse the options, fallback to the default domain
var wo registry.WatchOptions
for _, o := range opts {
o(&wo)
}
if len(wo.Domain) == 0 {
wo.Domain = registry.DefaultDomain
}
// construct the watcher
w := &Watcher{
exit: make(chan bool),
res: make(chan *registry.Result),
id: uuid.New().String(),
wo: wo,
}
m.Lock()
m.watchers[w.id] = w
m.Unlock()
return w, nil
}
func (m *Registry) String() string {
return "memory"
}