bash_completions: Generic function for --filename arguments

This generic function adds --filename= arguments to commands, and does
the magic so they get bash completions to find json, yaml, or yml files.

pkg/kubectl/bash_comp_utils.go

@@ -0,0 +1,40 @@
+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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.
+*/
+
+// A set of common functions needed by cmd/kubectl and pkg/kubectl packages.
+package kubectl
+
+import (
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+)
+
+func AddJsonFilenameFlag(cmd *cobra.Command, value *util.StringList, usage string) {
+	annotations := []string{"json", "yaml", "yml"}
+	annotation := make(map[string][]string)
+	annotation[cobra.BashCompFilenameExt] = annotations
+
+	flag := &pflag.Flag{
+		Name:        "filename",
+		Shorthand:   "f",
+		Usage:       usage,
+		Value:       value,
+		DefValue:    value.String(),
+		Annotations: annotation,
+	}
+	cmd.Flags().AddFlag(flag)
+}