ore aws: add ability to tag images

We need the ability to tag images to facilitate garbage collection
of RHCOS AMIs that are not used in boot images. The pre-existing
tagging functionality on the initial upload cannot be leveraged because
we don't know whether a RHCOS build will be used as a boot image
at build time.

mantle/cmd/ore/aws/tag-image.go

@@ -0,0 +1,69 @@
+// Copyright 2017 CoreOS, Inc.
+//
+// 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 aws
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	cmdTagImage = &cobra.Command{
+		Use:   "tag-image --ami <ami_id> --tags foo=bar ...",
+		Short: "Tag an AMI",
+		Run:   runTagImage,
+	}
+	tags []string
+)
+
+func init() {
+	// Initialize the command and its flags
+	AWS.AddCommand(cmdTagImage)
+	cmdTagImage.Flags().StringVar(&amiID, "ami", "", "AWS AMI ID")
+	cmdTagImage.Flags().StringVar(&region, "region", "", "Region")
+	cmdTagImage.Flags().StringSliceVar(&tags, "tags", []string{}, "list of key=value tags to attach to the AMI")
+}
+
+func runTagImage(cmd *cobra.Command, args []string) {
+	if amiID == "" {
+		fmt.Fprintf(os.Stderr, "Provide --ami to tag\n")
+		os.Exit(1)
+	}
+
+	if region == "" {
+		fmt.Fprintf(os.Stderr, "Provide --region\n")
+		os.Exit(1)
+	}
+
+	tagMap := make(map[string]string)
+	for _, tag := range tags {
+		splitTag := strings.SplitN(tag, "=", 2)
+		if len(splitTag) != 2 {
+			fmt.Fprintf(os.Stderr, "invalid tag format; should be key=value, not %v\n", tag)
+			os.Exit(1)
+		}
+		key, value := splitTag[0], splitTag[1]
+		tagMap[key] = value
+	}
+
+	err := API.CreateTags([]string{amiID}, tagMap)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "couldn't create image tags: %v", err)
+		os.Exit(1)
+	}
+}