pkg/splunk_logger: handle potentially dangling goroutine

pkg/splunk_logger/splunk_hook.go

@@ -1,6 +1,7 @@
 package logger
 
 import (
+	"context"
 	"fmt"
 	"os"
 
@@ -11,7 +12,7 @@ type SplunkHook struct {
 	sl *SplunkLogger
 }
 
-func NewSplunkHook(host, port, token, source string) (*SplunkHook, error) {
+func NewSplunkHook(context context.Context, host, port, token, source string) (*SplunkHook, error) {
 	url := fmt.Sprintf("https://%s:%s/services/collector/event", host, port)
 	hostname, err := os.Hostname()
 	if err != nil {
@@ -19,7 +20,7 @@ func NewSplunkHook(host, port, token, source string) (*SplunkHook, error) {
 	}
 
 	return &SplunkHook{
-		sl: NewSplunkLogger(url, token, source, hostname),
+		sl: NewSplunkLogger(context, url, token, source, hostname),
 	}, nil
 }
 

pkg/splunk_logger/splunk_logger.go

@@ -2,6 +2,7 @@ package logger
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -40,7 +41,7 @@ type SplunkEvent struct {
 	Host    string `json:"host"`
 }
 
-func NewSplunkLogger(url, token, source, hostname string) *SplunkLogger {
+func NewSplunkLogger(context context.Context, url, token, source, hostname string) *SplunkLogger {
 	sl := &SplunkLogger{
 		client:   retryablehttp.NewClient().StandardClient(),
 		url:      url,
@@ -52,15 +53,21 @@ func NewSplunkLogger(url, token, source, hostname string) *SplunkLogger {
 	ticker := time.NewTicker(time.Second * SendFrequency)
 	sl.payloads = make(chan *SplunkPayload, PayloadsChannelSize)
 
-	go sl.flushPayloads(ticker.C)
+	go sl.flushPayloads(context, ticker.C)
 
 	return sl
 }
 
-func (sl *SplunkLogger) flushPayloads(ticker <-chan time.Time) {
+func (sl *SplunkLogger) flushPayloads(context context.Context, ticker <-chan time.Time) {
 	var payloads []*SplunkPayload
 	for {
 		select {
+		case <-context.Done():
+			err := sl.SendPayloads(payloads)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Splunk logger unable to send payloads: %v", err)
+			}
+			return
 		case p := <-sl.payloads:
 			if p != nil {
 				payloads = append(payloads, p)

pkg/splunk_logger/splunk_logger_test.go

@@ -0,0 +1,65 @@
+package logger
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSplunkLogger(t *testing.T) {
+	ch := make(chan bool)
+	time.AfterFunc(time.Second*10, func() {
+		ch <- false
+	})
+	count := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// make sure the logger retries requests
+		if count == 0 {
+			count += 1
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		require.Equal(t, "Splunk", r.Header.Get("Authorization"))
+		require.Equal(t, "application/json", r.Header.Get("Content-Type"))
+		var sp SplunkPayload
+		err := json.NewDecoder(r.Body).Decode(&sp)
+		require.NoError(t, err)
+		require.Equal(t, "test-host", sp.Host)
+		require.Equal(t, "test-host", sp.Event.Host)
+		require.Equal(t, "image-builder", sp.Event.Ident)
+		require.Equal(t, "message", sp.Event.Message)
+		ch <- true
+	}))
+	sl := NewSplunkLogger(context.Background(), srv.URL, "", "image-builder", "test-host")
+	require.NoError(t, sl.LogWithTime(time.Now(), "message"))
+	require.True(t, <-ch)
+}
+
+func TestSplunkLoggerContext(t *testing.T) {
+	ch := make(chan bool)
+	time.AfterFunc(time.Second*10, func() {
+		ch <- false
+	})
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		require.Equal(t, "Splunk", r.Header.Get("Authorization"))
+		require.Equal(t, "application/json", r.Header.Get("Content-Type"))
+		var sp SplunkPayload
+		err := json.NewDecoder(r.Body).Decode(&sp)
+		require.NoError(t, err)
+		require.Equal(t, "test-host", sp.Host)
+		require.Equal(t, "test-host", sp.Event.Host)
+		require.Equal(t, "image-builder", sp.Event.Ident)
+		require.Equal(t, "message", sp.Event.Message)
+		ch <- true
+	}))
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*1)
+	defer cancel()
+	sl := NewSplunkLogger(ctx, srv.URL, "", "image-builder", "test-host")
+	require.NoError(t, sl.LogWithTime(time.Now(), "message"))
+	require.True(t, <-ch)
+}