Added "show" subcommand for printing out parameter store hierarchies

cmd/show.go

@@ -0,0 +1,131 @@
+// Copyright © 2017 Aidan Steele <aidan.steele@glassechidna.com.au>
+//
+// 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 cmd
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/ssm"
+	"github.com/aws/aws-sdk-go/aws"
+	"sort"
+	"github.com/fatih/color"
+	"encoding/json"
+)
+
+var showCmd = &cobra.Command{
+	Use:   "show <path>",
+	Short: "Prints all parameters under a prefix",
+	Long: `
+Prints all parameters under a given prefix. Defaults to human-friendly format,
+pass -j if you'd rather JSON output.
+`,
+	Run: func(cmd *cobra.Command, args []string) {
+		jsonFormat, _ := cmd.PersistentFlags().GetBool("json")
+		path := args[0]
+		show(path, jsonFormat)
+	},
+}
+
+func getAllParameters(sess *session.Session, path string) []*ssm.Parameter {
+	api := ssm.New(sess)
+
+	params := []*ssm.Parameter{}
+
+	api.GetParametersByPathPages(&ssm.GetParametersByPathInput{
+		Path: &path,
+		Recursive: aws.Bool(true),
+		WithDecryption: aws.Bool(true),
+	}, func(page *ssm.GetParametersByPathOutput, lastPage bool) bool {
+		params = append(params, page.Parameters...)
+		return !lastPage
+	})
+
+	sort.Sort(byName(params))
+	return params
+}
+
+func show(path string, jsonFormat bool) {
+	sess := session.Must(session.NewSession())
+	params := getAllParameters(sess, path)
+
+	if jsonFormat {
+		printJson(params, path)
+	} else {
+		printFriendly(params, path)
+	}
+}
+
+func printFriendly(params []*ssm.Parameter, path string) {
+	longest := longestName(params)
+	padding := longest - len(faint("%s", path))
+
+	secret := color.New(color.FgRed, color.Bold).SprintfFunc()
+
+	for _, param := range params {
+		prefix, rest := (*param.Name)[:len(path)], (*param.Name)[len(path):]
+		value := *param.Value
+
+		if *param.Type == ssm.ParameterTypeSecureString {
+			value = secret("%s", value)
+		}
+
+		fmt.Printf("%s%-*s : %s\n", faint("%s", prefix), padding, rest, value)
+	}
+}
+
+func printJson(params []*ssm.Parameter, path string) {
+	dict := map[string]string{}
+
+	for _, param := range params {
+		dict[*param.Name] = *param.Value
+	}
+
+	bytes, _ := json.MarshalIndent(dict, "", "  ")
+	fmt.Println(string(bytes))
+}
+
+type byName []*ssm.Parameter
+
+func (s byName) Len() int {
+	return len(s)
+}
+func (s byName) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+func (s byName) Less(i, j int) bool {
+	return *s[i].Name < *s[j].Name
+}
+
+func longestName(params []*ssm.Parameter) int {
+	longest := 0
+
+	for _, param := range params {
+		plen := len(faint("%s", *param.Name))
+		if plen > longest { longest = plen }
+	}
+
+	return longest
+}
+
+var faint func(format string, a ...interface{}) string
+
+func init() {
+	RootCmd.AddCommand(showCmd)
+	showCmd.PersistentFlags().BoolP("json", "j", false, "Emit JSON instead of table")
+
+	faint = color.New(color.Faint).SprintfFunc()
+}