micro/runtime/kubernetes/kubernetes.go
2020-04-23 17:14:30 +01:00

647 lines
15 KiB
Go

// Package kubernetes implements kubernetes micro runtime
package kubernetes
import (
"fmt"
"sync"
"time"
log "github.com/micro/go-micro/v2/logger"
"github.com/micro/go-micro/v2/runtime"
"github.com/micro/go-micro/v2/util/kubernetes/client"
)
// action to take on runtime service
type action int
type kubernetes struct {
sync.RWMutex
// options configure runtime
options runtime.Options
// indicates if we're running
running bool
// used to stop the runtime
closed chan bool
// client is kubernetes client
client client.Client
// namespaces which exist
namespaces []client.Namespace
}
// namespaceExists returns a boolean indicating if a namespace exists
func (k *kubernetes) namespaceExists(name string) (bool, error) {
// populate the cache
if k.namespaces == nil {
namespaceList := new(client.NamespaceList)
resource := &client.Resource{Kind: "namespace", Value: namespaceList}
if err := k.client.List(resource); err != nil {
return false, err
}
k.namespaces = namespaceList.Items
}
// check if the namespace exists in the cache
for _, n := range k.namespaces {
if n.Metadata.Name == name {
return true, nil
}
}
return false, nil
}
// createNamespace creates a new k8s namespace
func (k *kubernetes) createNamespace(namespace string) error {
ns := client.Namespace{Metadata: &client.Metadata{Name: namespace}}
err := k.client.Create(&client.Resource{Kind: "namespace", Value: ns})
// add to cache
if err == nil && k.namespaces != nil {
k.namespaces = append(k.namespaces, ns)
}
return err
}
// getService queries kubernetes for micro service
// NOTE: this function is not thread-safe
func (k *kubernetes) getService(labels map[string]string, opts ...client.GetOption) ([]*service, error) {
// get the service status
serviceList := new(client.ServiceList)
r := &client.Resource{
Kind: "service",
Value: serviceList,
}
opts = append(opts, client.GetLabels(labels))
// get the service from k8s
if err := k.client.Get(r, opts...); err != nil {
return nil, err
}
// get the deployment status
depList := new(client.DeploymentList)
d := &client.Resource{
Kind: "deployment",
Value: depList,
}
if err := k.client.Get(d, opts...); err != nil {
return nil, err
}
// get the pods from k8s
podList := new(client.PodList)
p := &client.Resource{
Kind: "pod",
Value: podList,
}
if err := k.client.Get(p, opts...); err != nil {
return nil, err
}
// service map
svcMap := make(map[string]*service)
// collect info from kubernetes service
for _, kservice := range serviceList.Items {
// name of the service
name := kservice.Metadata.Labels["name"]
// version of the service
version := kservice.Metadata.Labels["version"]
srv := &service{
Service: &runtime.Service{
Name: name,
Version: version,
Metadata: make(map[string]string),
},
kservice: &kservice,
}
// set the address
address := kservice.Spec.ClusterIP
port := kservice.Spec.Ports[0]
srv.Service.Metadata["address"] = fmt.Sprintf("%s:%d", address, port.Port)
// set the type of service
srv.Service.Metadata["type"] = kservice.Metadata.Labels["micro"]
// copy annotations metadata into service metadata
for k, v := range kservice.Metadata.Annotations {
srv.Service.Metadata[k] = v
}
// save as service
svcMap[name+version] = srv
}
// collect additional info from kubernetes deployment
for _, kdep := range depList.Items {
// name of the service
name := kdep.Metadata.Labels["name"]
// versio of the service
version := kdep.Metadata.Labels["version"]
// access existing service map based on name + version
if svc, ok := svcMap[name+version]; ok {
// we're expecting our own service name in metadata
if _, ok := kdep.Metadata.Annotations["name"]; !ok {
continue
}
// set the service name, version and source
// based on existing annotations we stored
svc.Service.Name = kdep.Metadata.Annotations["name"]
svc.Service.Version = kdep.Metadata.Annotations["version"]
svc.Service.Source = kdep.Metadata.Annotations["source"]
// delete from metadata
delete(kdep.Metadata.Annotations, "name")
delete(kdep.Metadata.Annotations, "version")
delete(kdep.Metadata.Annotations, "source")
// copy all annotations metadata into service metadata
for k, v := range kdep.Metadata.Annotations {
svc.Service.Metadata[k] = v
}
// parse out deployment status and inject into service metadata
if len(kdep.Status.Conditions) > 0 {
svc.Metadata["status"] = kdep.Status.Conditions[0].Type
svc.Metadata["started"] = kdep.Status.Conditions[0].LastUpdateTime
delete(svc.Metadata, "error")
} else {
svc.Metadata["status"] = "n/a"
}
// get the real status
for _, item := range podList.Items {
var status string
// check the name
if item.Metadata.Labels["name"] != name {
continue
}
// check the version
if item.Metadata.Labels["version"] != version {
continue
}
switch item.Status.Phase {
case "Failed":
status = item.Status.Reason
default:
status = item.Status.Phase
}
// skip if we can't get the container
if len(item.Status.Containers) == 0 {
continue
}
// now try get a deeper status
state := item.Status.Containers[0].State
// set start time
if state.Running != nil {
svc.Metadata["started"] = state.Running.Started
}
// set status from waiting
if v := state.Waiting; v != nil {
if len(v.Reason) > 0 {
status = v.Reason
}
}
// TODO: set from terminated
svc.Metadata["status"] = status
}
// save deployment
svc.kdeploy = &kdep
}
}
// collect all the services and return
services := make([]*service, 0, len(serviceList.Items))
for _, service := range svcMap {
services = append(services, service)
}
return services, nil
}
// run runs the runtime management loop
func (k *kubernetes) run(events <-chan runtime.Event) {
t := time.NewTicker(time.Second * 10)
defer t.Stop()
for {
select {
case <-t.C:
// TODO: figure out what to do here
// - do we even need the ticker for k8s services?
case event := <-events:
// NOTE: we only handle Update events for now
if log.V(log.DebugLevel, log.DefaultLogger) {
log.Debugf("Runtime received notification event: %v", event)
}
switch event.Type {
case runtime.Update:
// only process if there's an actual service
// we do not update all the things individually
if len(event.Service) == 0 {
continue
}
// format the name
name := client.Format(event.Service)
// set the default labels
labels := map[string]string{
"micro": k.options.Type,
"name": name,
}
if len(event.Version) > 0 {
labels["version"] = event.Version
}
// get the deployment status
deployed := new(client.DeploymentList)
// get the existing service rather than creating a new one
err := k.client.Get(&client.Resource{
Kind: "deployment",
Value: deployed,
}, client.GetLabels(labels))
if err != nil {
if log.V(log.DebugLevel, log.DefaultLogger) {
log.Debugf("Runtime update failed to get service %s: %v", event.Service, err)
}
continue
}
// technically we should not receive multiple versions but hey ho
for _, service := range deployed.Items {
// check the name matches
if service.Metadata.Name != name {
continue
}
// update build time annotation
if service.Spec.Template.Metadata.Annotations == nil {
service.Spec.Template.Metadata.Annotations = make(map[string]string)
}
// update the build time
service.Spec.Template.Metadata.Annotations["updated"] = fmt.Sprintf("%d", event.Timestamp.Unix())
if log.V(log.DebugLevel, log.DefaultLogger) {
log.Debugf("Runtime updating service: %s deployment: %s", event.Service, service.Metadata.Name)
}
if err := k.client.Update(deploymentResource(&service)); err != nil {
if log.V(log.DebugLevel, log.DefaultLogger) {
log.Debugf("Runtime failed to update service %s: %v", event.Service, err)
}
continue
}
}
}
case <-k.closed:
if log.V(log.DebugLevel, log.DefaultLogger) {
log.Debugf("Runtime stopped")
}
return
}
}
}
// Init initializes runtime options
func (k *kubernetes) Init(opts ...runtime.Option) error {
k.Lock()
defer k.Unlock()
for _, o := range opts {
o(&k.options)
}
return nil
}
func (k *kubernetes) Logs(s *runtime.Service, options ...runtime.LogsOption) (runtime.LogStream, error) {
klo := newLog(k.client, s.Name, options...)
stream, err := klo.Stream()
if err != nil {
return nil, err
}
// If requested, also read existing records and stream those too
if klo.options.Count > 0 {
go func() {
records, err := klo.Read()
if err != nil {
log.Errorf("Failed to get logs for service '%v' from k8s: %v", err)
return
}
// @todo: this might actually not run before podLogStream starts
// and might cause out of order log retrieval at the receiving end.
// A better approach would probably to suppor this inside the `klog.Stream` method.
for _, record := range records {
stream.Chan() <- record
}
}()
}
return stream, nil
}
type kubeStream struct {
// the k8s log stream
stream chan runtime.LogRecord
// the stop chan
sync.Mutex
stop chan bool
err error
}
func (k *kubeStream) Error() error {
return k.err
}
func (k *kubeStream) Chan() chan runtime.LogRecord {
return k.stream
}
func (k *kubeStream) Stop() error {
k.Lock()
defer k.Unlock()
select {
case <-k.stop:
return nil
default:
close(k.stop)
close(k.stream)
}
return nil
}
// Creates a service
func (k *kubernetes) Create(s *runtime.Service, opts ...runtime.CreateOption) error {
k.Lock()
defer k.Unlock()
options := runtime.CreateOptions{
Type: k.options.Type,
Namespace: client.DefaultNamespace,
}
for _, o := range opts {
o(&options)
}
// default type if it doesn't exist
if len(options.Type) == 0 {
options.Type = k.options.Type
}
// default the source if it doesn't exist
if len(s.Source) == 0 {
s.Source = k.options.Source
}
// ensure the namespace exists
namespace := client.SerializeResourceName(options.Namespace)
if exist, err := k.namespaceExists(namespace); err == nil && !exist {
if err := k.createNamespace(namespace); err != nil {
return err
}
} else if err != nil {
return err
}
// determine the image from the source and options
options.Image = k.getImage(s, options)
// create new service
service := newService(s, options)
// start the service
return service.Start(k.client, client.CreateNamespace(options.Namespace))
}
// Read returns all instances of given service
func (k *kubernetes) Read(opts ...runtime.ReadOption) ([]*runtime.Service, error) {
k.Lock()
defer k.Unlock()
// set the default labels
labels := map[string]string{
"micro": k.options.Type,
}
options := runtime.ReadOptions{
Namespace: client.DefaultNamespace,
}
for _, o := range opts {
o(&options)
}
if len(options.Service) > 0 {
labels["name"] = client.Format(options.Service)
}
// add version to labels if a version has been supplied
if len(options.Version) > 0 {
labels["version"] = options.Version
}
if len(options.Type) > 0 {
labels["micro"] = options.Type
}
srvs, err := k.getService(labels, client.GetNamespace(options.Namespace))
if err != nil {
return nil, err
}
var services []*runtime.Service
for _, service := range srvs {
services = append(services, service.Service)
}
return services, nil
}
// Update the service in place
func (k *kubernetes) Update(s *runtime.Service, opts ...runtime.UpdateOption) error {
options := runtime.UpdateOptions{
Namespace: client.DefaultNamespace,
}
for _, o := range opts {
o(&options)
}
labels := map[string]string{}
if len(s.Name) > 0 {
labels["name"] = client.Format(s.Name)
}
if len(s.Version) > 0 {
labels["version"] = s.Version
}
// get the existing service
services, err := k.getService(labels)
if err != nil {
return err
}
// update the relevant services
for _, service := range services {
// nil check
if service.kdeploy.Metadata == nil || service.kdeploy.Metadata.Annotations == nil {
md := new(client.Metadata)
md.Annotations = make(map[string]string)
service.kdeploy.Metadata = md
}
// update metadata
for k, v := range s.Metadata {
service.kdeploy.Metadata.Annotations[k] = v
}
// update build time annotation
service.kdeploy.Spec.Template.Metadata.Annotations["updated"] = fmt.Sprintf("%d", time.Now().Unix())
// update the service
if err := service.Update(k.client, client.UpdateNamespace(options.Namespace)); err != nil {
return err
}
}
return nil
}
// Delete removes a service
func (k *kubernetes) Delete(s *runtime.Service, opts ...runtime.DeleteOption) error {
options := runtime.DeleteOptions{
Namespace: client.DefaultNamespace,
}
for _, o := range opts {
o(&options)
}
k.Lock()
defer k.Unlock()
// create new kubernetes micro service
service := newService(s, runtime.CreateOptions{
Type: k.options.Type,
Namespace: options.Namespace,
})
return service.Stop(k.client, client.DeleteNamespace(options.Namespace))
}
// Start starts the runtime
func (k *kubernetes) Start() error {
k.Lock()
defer k.Unlock()
// already running
if k.running {
return nil
}
// set running
k.running = true
k.closed = make(chan bool)
var events <-chan runtime.Event
if k.options.Scheduler != nil {
var err error
events, err = k.options.Scheduler.Notify()
if err != nil {
// TODO: should we bail here?
if log.V(log.DebugLevel, log.DefaultLogger) {
log.Debugf("Runtime failed to start update notifier")
}
}
}
go k.run(events)
return nil
}
// Stop shuts down the runtime
func (k *kubernetes) Stop() error {
k.Lock()
defer k.Unlock()
if !k.running {
return nil
}
select {
case <-k.closed:
return nil
default:
close(k.closed)
// set not running
k.running = false
// stop the scheduler
if k.options.Scheduler != nil {
return k.options.Scheduler.Close()
}
}
return nil
}
// String implements stringer interface
func (k *kubernetes) String() string {
return "kubernetes"
}
// NewRuntime creates new kubernetes runtime
func NewRuntime(opts ...runtime.Option) runtime.Runtime {
// get default options
options := runtime.Options{
// Create labels with type "micro": "service"
Type: "service",
}
// apply requested options
for _, o := range opts {
o(&options)
}
// kubernetes client
client := client.NewClusterClient()
return &kubernetes{
options: options,
closed: make(chan bool),
client: client,
}
}
func (k *kubernetes) getImage(s *runtime.Service, options runtime.CreateOptions) string {
// use the image when its specified
if len(options.Image) > 0 {
return options.Image
}
if len(k.options.Image) > 0 {
return k.options.Image
}
return ""
}