chore: Move private packages to internal (#1664)

internal/log/flag/flag.go

@@ -0,0 +1,37 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package flag
+
+import (
+	"github.com/alecthomas/kingpin/v2"
+	"github.com/prometheus-community/windows_exporter/internal/log"
+	"github.com/prometheus/common/promslog"
+	"github.com/prometheus/common/promslog/flag"
+)
+
+// FileFlagName is the canonical flag name to configure the log file.
+const FileFlagName = "log.file"
+
+// FileFlagHelp is the help description for the log.file flag.
+const FileFlagHelp = "Output file of log messages. One of [stdout, stderr, eventlog, <path to log file>]"
+
+// AddFlags adds the flags used by this package to the Kingpin application.
+// To use the default Kingpin application, call AddFlags(kingpin.CommandLine).
+func AddFlags(a *kingpin.Application, config *log.Config) {
+	config.Config = new(promslog.Config)
+	flag.AddFlags(a, config.Config)
+
+	config.File = &log.AllowedFile{}
+	a.Flag(FileFlagName, FileFlagHelp).Default("stderr").SetValue(config.File)
+}