Make logs more testable (#2940)

* make logs more testable
Signed-off-by: Cliff Colvin <ccolvin@kubecost.com>

* add tests
Signed-off-by: Cliff Colvin <ccolvin@kubecost.com>

* update test
Signed-off-by: Cliff Colvin <ccolvin@kubecost.com>

core/pkg/log/log.go

@@ -49,6 +49,14 @@ func InitLogging(showLogLevelSetMessage bool) {
 
 }
 
+func GetLogger() *zerolog.Logger {
+	return &log.Logger
+}
+
+func SetLogger(l *zerolog.Logger) {
+	log.Logger = *l
+}
+
 func GetLogLevel() string {
 	return zerolog.GlobalLevel().String()
 }

core/pkg/log/log_test.go

@@ -0,0 +1,64 @@
+package log
+
+import (
+	"bytes"
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/rs/zerolog"
+)
+
+func TestGetLogger(t *testing.T) {
+	initialLogger := GetLogger()
+	if initialLogger == nil {
+		t.Error("GetLogger() returned nil")
+	}
+
+	secondLogger := GetLogger()
+	if initialLogger != secondLogger {
+		t.Error("GetLogger() returned different loggers on subsequent calls")
+	}
+}
+
+func TestSetLogger(t *testing.T) {
+	var buf bytes.Buffer
+	newLogger := zerolog.New(&buf).With().Str("test", "value").Logger()
+	SetLogger(&newLogger)
+
+	// Log a message using the global logger
+	Infof("Test message")
+
+	// Parse the logged message
+	loggedData := parseLogMessage(t, buf.String())
+
+	// Check if the "test" field is present in the logged message
+	if value, exists := loggedData["test"]; !exists || value != "value" {
+		t.Error("SetLogger() did not set the logger with expected context")
+	}
+}
+
+func TestLoggerConsistency(t *testing.T) {
+	var buf bytes.Buffer
+	newLogger := zerolog.New(&buf).With().Str("test", "consistency").Logger()
+	SetLogger(&newLogger)
+
+	// Log a message using the global logger
+	Infof("Consistency test message")
+
+	// Parse the logged message
+	loggedData := parseLogMessage(t, buf.String())
+
+	// Check if the "test" field is present in the logged message
+	if value, exists := loggedData["test"]; !exists || value != "consistency" {
+		t.Error("Logger inconsistency: Updated logger does not have expected context")
+	}
+}
+
+func parseLogMessage(t *testing.T, logMessage string) map[string]interface{} {
+	var loggedData map[string]interface{}
+	if err := json.Unmarshal([]byte(strings.TrimSpace(logMessage)), &loggedData); err != nil {
+		t.Fatalf("Failed to parse logged message: %v", err)
+	}
+	return loggedData
+}