Adds a test to ensure the file output works

Author: e_forbes

go.sum

@@ -554,8 +554,6 @@ gitlab.com/gitlab-org/gitaly/v16 v16.11.0-rc1.0.20250408053233-c6d43513e93c h1:x
 gitlab.com/gitlab-org/gitaly/v16 v16.11.0-rc1.0.20250408053233-c6d43513e93c/go.mod h1:/rkj6992VsNymUeG6N3VnLZ8Pvb1Y9ZUo00Yy35t8WQ=
 gitlab.com/gitlab-org/go/reopen v1.0.0 h1:6BujZ0lkkjGIejTUJdNO1w56mN1SI10qcVQyQlOPM+8=
 gitlab.com/gitlab-org/go/reopen v1.0.0/go.mod h1:D6OID8YJDzEVZNYW02R/Pkj0v8gYFSIhXFTArAsBQw8=
-gitlab.com/gitlab-org/labkit v1.35.0 h1:6PSRUvmuEKFrAZpQPLlMNIdbtZHyKHaqyRlM4PDYDbs=
-gitlab.com/gitlab-org/labkit v1.35.0/go.mod h1:JqQLdgjV/KKAZJ6gvNodaLStmWeTT9mxgJPIEi66VHI=
 gitlab.com/gitlab-org/labkit v1.36.0 h1:QA60DLXmtOyIRchrxaRwonrtbviWQogA623tR2JijE4=
 gitlab.com/gitlab-org/labkit v1.36.0/go.mod h1:JqQLdgjV/KKAZJ6gvNodaLStmWeTT9mxgJPIEi66VHI=
 go.etcd.io/raft/v3 v3.6.0 h1:5NtvbDVYpnfZWcIHgGRk9DyzkBIXOi8j+DDp1IcnUWQ=

internal/logger/logger_test.go

@@ -98,3 +98,22 @@ func createTempFile(t *testing.T) string {
 
 	return tmpFile.Name()
 }
+
+func TestConfigureLabkitV2Log(t *testing.T) {
+	tmpFile := createTempFile(t)
+	config := config.Config{
+		LogFile:   tmpFile,
+		LogFormat: "json",
+		LogLevel:  "debug",
+	}
+
+	logger := ConfigureLogger(&config)
+	logger.Info("this is a test")
+	logger.Debug("debug log message")
+
+	data, err := os.ReadFile(tmpFile)
+	dataStr := string(data)
+	require.NoError(t, err)
+	require.Contains(t, dataStr, `"msg":"this is a test"`)
+	require.Contains(t, dataStr, `"msg":"debug log message"`)
+}