Kubernetes logging (#1054)

* wip

* Implementation of Kubernetes Logger

* Missing file

* Skip test in Travis

debug/log/kubernetes/kubernetes.go

@@ -2,15 +2,62 @@
 package kubernetes
 
 import (
-	"errors"
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+	"time"
 
 	"github.com/micro/go-micro/debug/log"
+	"github.com/micro/go-micro/util/kubernetes/client"
 )
 
-type klog struct{}
+type klog struct {
+	client client.Kubernetes
 
-func (k *klog) Read(...log.ReadOption) ([]log.Record, error) {
-	return nil, errors.New("not implemented")
+	log.Options
+}
+
+func (k *klog) Read(options ...log.ReadOption) ([]log.Record, error) {
+	opts := &log.ReadOptions{}
+	for _, o := range options {
+		o(opts)
+	}
+
+	logsToGet, err := k.getMatchingPods()
+	if err != nil {
+		return nil, err
+	}
+	records := []log.Record{}
+
+	for _, l := range logsToGet {
+		logParams := make(map[string]string)
+		if !opts.Since.Equal(time.Time{}) {
+			logParams["sinceSeconds"] = strconv.Itoa(int(time.Since(opts.Since).Seconds()))
+		}
+		if opts.Count != 0 {
+			logParams["tailLines"] = strconv.Itoa(opts.Count)
+		}
+		if opts.Stream == true {
+			logParams["follow"] = "true"
+		}
+		logs, err := k.client.Logs(l, client.AdditionalParams(logParams))
+		if err != nil {
+			return nil, err
+		}
+		defer logs.Close()
+		s := bufio.NewScanner(logs)
+		for s.Scan() {
+			record := k.parse(s.Text())
+			record.Metadata["pod"] = l
+			records = append(records, record)
+		}
+	}
+
+	sort.Sort(byTimestamp(records))
+	return records, nil
 }
 
 func (k *klog) Write(l log.Record) error {
@@ -18,13 +65,102 @@ func (k *klog) Write(l log.Record) error {
 }
 
 func (k *klog) Stream() (log.Stream, error) {
-	return &klogStreamer{
+	return k.stream()
+}
+
+func (k *klog) stream() (log.Stream, error) {
+	pods, err := k.getMatchingPods()
+	if err != nil {
+		return nil, err
+	}
+	logStreamer := &klogStreamer{
 		streamChan: make(chan log.Record),
 		stop:       make(chan bool),
-	}, nil
+	}
+	errorChan := make(chan error)
+	go func(stopChan <-chan bool) {
+		for {
+			select {
+			case <-stopChan:
+				return
+			case err := <-errorChan:
+				fmt.Fprintf(os.Stderr, err.Error())
+			}
+		}
+	}(logStreamer.stop)
+	for _, pod := range pods {
+		go k.individualPodLogStreamer(pod, logStreamer.streamChan, errorChan, logStreamer.stop)
+	}
+	return logStreamer, nil
+}
+
+func (k *klog) individualPodLogStreamer(podName string, recordChan chan<- log.Record, errorChan chan<- error, stopChan <-chan bool) {
+	p := make(map[string]string)
+	p["follow"] = "true"
+	body, err := k.client.Logs(podName, client.AdditionalParams(p))
+	if err != nil {
+		errorChan <- err
+		return
+	}
+	s := bufio.NewScanner(body)
+	defer body.Close()
+	for {
+		select {
+		case <-stopChan:
+			return
+		default:
+			if s.Scan() {
+				record := k.parse(s.Text())
+				recordChan <- record
+			} else {
+				time.Sleep(time.Second)
+			}
+		}
+	}
 }
 
 // New returns a configured Kubernetes logger
-func New() log.Log {
-	return &klog{}
+func New(opts ...log.Option) log.Log {
+	klog := &klog{}
+	for _, o := range opts {
+		o(&klog.Options)
+	}
+
+	if len(os.Getenv("KUBERNETES_SERVICE_HOST")) > 0 {
+		klog.client = client.NewClientInCluster()
+	} else {
+		klog.client = client.NewLocalDevClient()
+	}
+	return klog
+}
+
+func (k *klog) getMatchingPods() ([]string, error) {
+	r := &client.Resource{
+		Kind:  "pod",
+		Value: new(client.PodList),
+	}
+	l := make(map[string]string)
+	l["micro"] = "runtime"
+	if err := k.client.Get(r, l); err != nil {
+		return nil, err
+	}
+
+	var matches []string
+	for _, p := range r.Value.(*client.PodList).Items {
+		if p.Metadata.Labels["name"] == k.Options.Name {
+			matches = append(matches, p.Metadata.Name)
+		}
+	}
+	return matches, nil
+}
+
+func (k *klog) parse(line string) log.Record {
+	record := log.Record{}
+	if err := json.Unmarshal([]byte(line), &record); err != nil {
+		record.Timestamp = time.Now().UTC()
+		record.Message = line
+		record.Metadata = make(map[string]string)
+	}
+	record.Metadata["service"] = k.Options.Name
+	return record
 }

debug/log/kubernetes/kubernetes_test.go

@@ -13,7 +13,10 @@ import (
 )
 
 func TestKubernetes(t *testing.T) {
-	k := New()
+	if os.Getenv("IN_TRAVIS_CI") == "yes" {
+		t.Skip("In Travis CI")
+	}
+	k := New(log.Name("micro-network"))
 
 	r, w, err := os.Pipe()
 	if err != nil {
@@ -39,14 +42,15 @@ func TestKubernetes(t *testing.T) {
 	}
 	assert.Equal(t, write, read, "Write was not equal")
 
-	_, err = k.Read()
-	assert.Error(t, err, "Read should be unimplemented")
+	records, err := k.Read()
+	assert.Nil(t, err, "Read should not error")
+	assert.NotNil(t, records, "Read should return records")
 
 	stream, err := k.Stream()
 	if err != nil {
 		t.Error(err)
 	}
-	records := []log.Record{}
+	records = []log.Record{}
 	go stream.Stop()
 	for s := range stream.Chan() {
 		records = append(records, s)

debug/log/kubernetes/util.go

@@ -0,0 +1,15 @@
+package kubernetes
+
+import "github.com/micro/go-micro/debug/log"
+
+// ByTimestamp lets you sort log records by Timestamp (implements Sort.Sort)
+type byTimestamp []log.Record
+
+// Len returns the number of Log records (implements Sort.Sort)
+func (b byTimestamp) Len() int { return len(b) }
+
+// Swap swaps 2 Log records (implements Sort.Sort)
+func (b byTimestamp) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
+
+// Less checks if a record was before another record (implements Sort.Sort)
+func (b byTimestamp) Less(i, j int) bool { return b[i].Timestamp.Before(b[j].Timestamp) }

util/kubernetes/client/api/request.go

@@ -34,6 +34,7 @@ type Request struct {
 type Params struct {
 	LabelSelector map[string]string
 	Annotations   map[string]string
+	Additional    map[string]string
 }
 
 // verb sets method
@@ -136,6 +137,9 @@ func (r *Request) Params(p *Params) *Request {
 		// set and overwrite the value
 		r.params.Set("labelSelector", value)
 	}
+	for k, v := range p.Additional {
+		r.params.Set(k, v)
+	}
 
 	return r
 }

util/kubernetes/client/client.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"os"
 	"path"
+	"strconv"
 
 	"github.com/micro/go-micro/util/kubernetes/client/api"
 	"github.com/micro/go-micro/util/log"
@@ -26,6 +27,26 @@ type client struct {
 	opts *api.Options
 }
 
+// NewLocalDevClient returns a client that can be used with `kubectl proxy` on an optional port
+func NewLocalDevClient(port ...int) *client {
+	var p int
+	if len(port) > 1 {
+		log.Fatal("Expected 0 or 1 port parameters")
+	}
+	if len(port) == 0 {
+		p = 8001
+	} else {
+		p = port[0]
+	}
+	return &client{
+		opts: &api.Options{
+			Client:    http.DefaultClient,
+			Host:      "http://localhost:" + strconv.Itoa(p),
+			Namespace: "default",
+		},
+	}
+}
+
 // NewClientInCluster creates a Kubernetes client for use from within a k8s pod.
 func NewClientInCluster() *client {
 	host := "https://" + os.Getenv("KUBERNETES_SERVICE_HOST") + ":" + os.Getenv("KUBERNETES_SERVICE_PORT")
@@ -118,17 +139,29 @@ func (c *client) Get(r *Resource, labels map[string]string) error {
 }
 
 // Logs returns logs for a pod
-func (c *client) Logs(podName string) (io.ReadCloser, error) {
+func (c *client) Logs(podName string, options ...LogOption) (io.ReadCloser, error) {
+	opts := &LogOptions{}
+	for _, o := range options {
+		o(opts)
+	}
 	req := api.NewRequest(c.opts).
 		Get().
 		Resource("pod").
 		SubResource("log").
 		Name(podName)
 
+	if opts.AdditionalParams != nil {
+		req.Params(&api.Params{Additional: opts.AdditionalParams})
+	}
+
 	resp, err := req.Raw()
 	if err != nil {
 		return nil, err
 	}
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		resp.Body.Close()
+		return nil, errors.New(resp.Request.URL.String() + ": " + resp.Status)
+	}
 	return resp.Body, nil
 }
 

util/kubernetes/client/kubernetes.go

@@ -26,7 +26,7 @@ type Kubernetes interface {
 	// List lists API resources
 	List(*Resource) error
 	// Logs gets logs from a pod
-	Logs(string) (io.ReadCloser, error)
+	Logs(string, ...LogOption) (io.ReadCloser, error)
 }
 
 // NewService returns default micro kubernetes service definition

util/kubernetes/client/logoptions.go

@@ -0,0 +1,13 @@
+package client
+
+type LogOptions struct {
+	AdditionalParams map[string]string
+}
+
+type LogOption func(*LogOptions)
+
+func AdditionalParams(p map[string]string) LogOption {
+	return func(l *LogOptions) {
+		l.AdditionalParams = p
+	}
+}

util/kubernetes/client/types.go

@@ -79,7 +79,7 @@ type Container struct {
 	Ports   []ContainerPort `json:"ports,omitempty"`
 }
 
-// PodSpec
+// PodSpec is a pod
 type PodSpec struct {
 	Containers []Container `json:"containers"`
 }
@@ -131,3 +131,7 @@ type Deployment struct {
 type DeploymentList struct {
 	Items []Deployment `json:"items"`
 }
+
+type PodList struct {
+	Items []Template `json:"items"`
+}