micro/api/router/registry/registry.go
2020-06-12 10:42:52 +01:00

499 lines
10 KiB
Go

// Package registry provides a dynamic api service router
package registry
import (
"errors"
"fmt"
"net/http"
"regexp"
"strings"
"sync"
"time"
"github.com/micro/go-micro/v2/api"
"github.com/micro/go-micro/v2/api/router"
"github.com/micro/go-micro/v2/api/router/util"
"github.com/micro/go-micro/v2/logger"
"github.com/micro/go-micro/v2/metadata"
"github.com/micro/go-micro/v2/registry"
"github.com/micro/go-micro/v2/registry/cache"
)
// endpoint struct, that holds compiled pcre
type endpoint struct {
hostregs []*regexp.Regexp
pathregs []util.Pattern
pcreregs []*regexp.Regexp
}
// router is the default router
type registryRouter struct {
exit chan bool
opts router.Options
// registry cache
rc cache.Cache
sync.RWMutex
eps map[string]*api.Service
// compiled regexp for host and path
ceps map[string]*endpoint
}
func (r *registryRouter) isClosed() bool {
select {
case <-r.exit:
return true
default:
return false
}
}
// refresh list of api services
func (r *registryRouter) refresh() {
var attempts int
for {
services, err := r.opts.Registry.ListServices()
if err != nil {
attempts++
if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
logger.Errorf("unable to list services: %v", err)
}
time.Sleep(time.Duration(attempts) * time.Second)
continue
}
attempts = 0
// for each service, get service and store endpoints
for _, s := range services {
service, err := r.rc.GetService(s.Name)
if err != nil {
if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
logger.Errorf("unable to get service: %v", err)
}
continue
}
r.store(service)
}
// refresh list in 10 minutes... cruft
// use registry watching
select {
case <-time.After(time.Minute * 10):
case <-r.exit:
return
}
}
}
// process watch event
func (r *registryRouter) process(res *registry.Result) {
// skip these things
if res == nil || res.Service == nil {
return
}
// get entry from cache
service, err := r.rc.GetService(res.Service.Name)
if err != nil {
if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
logger.Errorf("unable to get service: %v", err)
}
return
}
// update our local endpoints
r.store(service)
}
// store local endpoint cache
func (r *registryRouter) store(services []*registry.Service) {
// endpoints
eps := map[string]*api.Service{}
// services
names := map[string]bool{}
// create a new endpoint mapping
for _, service := range services {
// set names we need later
names[service.Name] = true
// map per endpoint
for _, sep := range service.Endpoints {
// create a key service:endpoint_name
key := fmt.Sprintf("%s.%s", service.Name, sep.Name)
// decode endpoint
end := api.Decode(sep.Metadata)
// if we got nothing skip
if err := api.Validate(end); err != nil {
if logger.V(logger.TraceLevel, logger.DefaultLogger) {
logger.Tracef("endpoint validation failed: %v", err)
}
continue
}
// try get endpoint
ep, ok := eps[key]
if !ok {
ep = &api.Service{Name: service.Name}
}
// overwrite the endpoint
ep.Endpoint = end
// append services
ep.Services = append(ep.Services, service)
// store it
eps[key] = ep
}
}
r.Lock()
defer r.Unlock()
// delete any existing eps for services we know
for key, service := range r.eps {
// skip what we don't care about
if !names[service.Name] {
continue
}
// ok we know this thing
// delete delete delete
delete(r.eps, key)
}
// now set the eps we have
for name, ep := range eps {
r.eps[name] = ep
cep := &endpoint{}
for _, h := range ep.Endpoint.Host {
if h == "" || h == "*" {
continue
}
hostreg, err := regexp.CompilePOSIX(h)
if err != nil {
if logger.V(logger.TraceLevel, logger.DefaultLogger) {
logger.Tracef("endpoint have invalid host regexp: %v", err)
}
continue
}
cep.hostregs = append(cep.hostregs, hostreg)
}
for _, p := range ep.Endpoint.Path {
var pcreok bool
if p[0] == '^' && p[len(p)-1] == '$' {
pcrereg, err := regexp.CompilePOSIX(p)
if err == nil {
cep.pcreregs = append(cep.pcreregs, pcrereg)
pcreok = true
}
}
rule, err := util.Parse(p)
if err != nil && !pcreok {
if logger.V(logger.TraceLevel, logger.DefaultLogger) {
logger.Tracef("endpoint have invalid path pattern: %v", err)
}
continue
} else if err != nil && pcreok {
continue
}
tpl := rule.Compile()
pathreg, err := util.NewPattern(tpl.Version, tpl.OpCodes, tpl.Pool, "")
if err != nil {
if logger.V(logger.TraceLevel, logger.DefaultLogger) {
logger.Tracef("endpoint have invalid path pattern: %v", err)
}
continue
}
cep.pathregs = append(cep.pathregs, pathreg)
}
r.ceps[name] = cep
}
}
// watch for endpoint changes
func (r *registryRouter) watch() {
var attempts int
for {
if r.isClosed() {
return
}
// watch for changes
w, err := r.opts.Registry.Watch()
if err != nil {
attempts++
if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
logger.Errorf("error watching endpoints: %v", err)
}
time.Sleep(time.Duration(attempts) * time.Second)
continue
}
ch := make(chan bool)
go func() {
select {
case <-ch:
w.Stop()
case <-r.exit:
w.Stop()
}
}()
// reset if we get here
attempts = 0
for {
// process next event
res, err := w.Next()
if err != nil {
if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
logger.Errorf("error getting next endoint: %v", err)
}
close(ch)
break
}
r.process(res)
}
}
}
func (r *registryRouter) Options() router.Options {
return r.opts
}
func (r *registryRouter) Close() error {
select {
case <-r.exit:
return nil
default:
close(r.exit)
r.rc.Stop()
}
return nil
}
func (r *registryRouter) Register(ep *api.Endpoint) error {
return nil
}
func (r *registryRouter) Deregister(ep *api.Endpoint) error {
return nil
}
func (r *registryRouter) Endpoint(req *http.Request) (*api.Service, error) {
if r.isClosed() {
return nil, errors.New("router closed")
}
r.RLock()
defer r.RUnlock()
var idx int
if len(req.URL.Path) > 0 && req.URL.Path != "/" {
idx = 1
}
path := strings.Split(req.URL.Path[idx:], "/")
// use the first match
// TODO: weighted matching
for n, e := range r.eps {
cep, ok := r.ceps[n]
if !ok {
continue
}
ep := e.Endpoint
var mMatch, hMatch, pMatch bool
// 1. try method
for _, m := range ep.Method {
if m == req.Method {
mMatch = true
break
}
}
if !mMatch {
continue
}
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("api method match %s", req.Method)
}
// 2. try host
if len(ep.Host) == 0 {
hMatch = true
} else {
for idx, h := range ep.Host {
if h == "" || h == "*" {
hMatch = true
break
} else {
if cep.hostregs[idx].MatchString(req.URL.Host) {
hMatch = true
break
}
}
}
}
if !hMatch {
continue
}
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("api host match %s", req.URL.Host)
}
// 3. try path via google.api path matching
for _, pathreg := range cep.pathregs {
matches, err := pathreg.Match(path, "")
if err != nil {
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("api gpath not match %s != %v", path, pathreg)
}
continue
}
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("api gpath match %s = %v", path, pathreg)
}
pMatch = true
ctx := req.Context()
md, ok := metadata.FromContext(ctx)
if !ok {
md = make(metadata.Metadata)
}
for k, v := range matches {
md[fmt.Sprintf("x-api-field-%s", k)] = v
}
md["x-api-body"] = ep.Body
*req = *req.Clone(metadata.NewContext(ctx, md))
break
}
if !pMatch {
// 4. try path via pcre path matching
for _, pathreg := range cep.pcreregs {
if !pathreg.MatchString(req.URL.Path) {
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("api pcre path not match %s != %v", path, pathreg)
}
continue
}
if logger.V(logger.DebugLevel, logger.DefaultLogger) {
logger.Debugf("api pcre path match %s != %v", path, pathreg)
}
pMatch = true
break
}
}
if !pMatch {
continue
}
// TODO: Percentage traffic
// we got here, so its a match
return e, nil
}
// no match
return nil, errors.New("not found")
}
func (r *registryRouter) Route(req *http.Request) (*api.Service, error) {
if r.isClosed() {
return nil, errors.New("router closed")
}
// try get an endpoint
ep, err := r.Endpoint(req)
if err == nil {
return ep, nil
}
// error not nil
// ignore that shit
// TODO: don't ignore that shit
// get the service name
rp, err := r.opts.Resolver.Resolve(req)
if err != nil {
return nil, err
}
// service name
name := rp.Name
// get service
services, err := r.rc.GetService(name)
if err != nil {
return nil, err
}
// only use endpoint matching when the meta handler is set aka api.Default
switch r.opts.Handler {
// rpc handlers
case "meta", "api", "rpc":
handler := r.opts.Handler
// set default handler to api
if r.opts.Handler == "meta" {
handler = "rpc"
}
// construct api service
return &api.Service{
Name: name,
Endpoint: &api.Endpoint{
Name: rp.Method,
Handler: handler,
},
Services: services,
}, nil
// http handler
case "http", "proxy", "web":
// construct api service
return &api.Service{
Name: name,
Endpoint: &api.Endpoint{
Name: req.URL.String(),
Handler: r.opts.Handler,
Host: []string{req.Host},
Method: []string{req.Method},
Path: []string{req.URL.Path},
},
Services: services,
}, nil
}
return nil, errors.New("unknown handler")
}
func newRouter(opts ...router.Option) *registryRouter {
options := router.NewOptions(opts...)
r := &registryRouter{
exit: make(chan bool),
opts: options,
rc: cache.New(options.Registry),
eps: make(map[string]*api.Service),
ceps: make(map[string]*endpoint),
}
go r.watch()
go r.refresh()
return r
}
// NewRouter returns the default router
func NewRouter(opts ...router.Option) router.Router {
return newRouter(opts...)
}