Add more fields, default table format and --format custom format flag to config list command

Dockerfile

@@ -2,6 +2,7 @@ FROM alpine:3
 
 ENV PSU_AUTH_TOKEN="" \
   PSU_CONFIG="" \
+  PSU_CONFIG_LIST_FORMAT="" \
   PSU_ENDPOINT_GROUP_LIST_FORMAT="" \
   PSU_ENDPOINT_LIST_FORMAT="" \
   PSU_INSECURE="" \

cmd/config.go

@@ -29,7 +29,7 @@ var configCmd = &cobra.Command{
 		if !keyExists {
 			logrus.WithFields(logrus.Fields{
 				"key":         args[0],
-				"suggestions": "Try looking up the available configuration keys: psu config ls --keys",
+				"suggestions": "Try looking up the available configuration keys: psu config ls",
 			}).Fatal("Unknown configuration key")
 		}
 

cmd/configList.go

@@ -2,7 +2,12 @@ package cmd
 
 import (
 	"fmt"
+	"os"
 	"sort"
+	"strings"
+	"text/template"
+
+	"github.com/greenled/portainer-stack-utils/common"
 
 	"github.com/spf13/viper"
 
@@ -21,13 +26,61 @@ var configListCmd = &cobra.Command{
 			return keys[i] < keys[j]
 		})
 
+		// Create config objects
+		var configs []config
 		for _, key := range keys {
-			// List config key and value
-			fmt.Printf("%s: %v\n", key, viper.Get(key))
+			envvar := strings.Replace(key, "-", "_", -1)
+			envvar = strings.Replace(envvar, ".", "_", -1)
+			envvar = strings.ToUpper(envvar)
+			envvar = "PSU_" + envvar
+			configs = append(configs, config{
+				Key:                 key,
+				EnvironmentVariable: envvar,
+				CurrentValue:        viper.Get(key),
+			})
+		}
+
+		if viper.GetString("config.list.format") != "" {
+			// Print configs with a custom format
+			template, templateParsingErr := template.New("configTpl").Parse(viper.GetString("config.list.format"))
+			common.CheckError(templateParsingErr)
+			for _, c := range configs {
+				templateExecutionErr := template.Execute(os.Stdout, c)
+				common.CheckError(templateExecutionErr)
+				fmt.Println()
+			}
+		} else {
+			// Print configs with a table format
+			writer, err := common.NewTabWriter([]string{
+				"KEY",
+				"ENV VAR",
+				"CURRENT VALUE",
+			})
+			common.CheckError(err)
+			for _, c := range configs {
+				_, err := fmt.Fprintln(writer, fmt.Sprintf(
+					"%s\t%s\t%v",
+					c.Key,
+					c.EnvironmentVariable,
+					c.CurrentValue,
+				))
+				common.CheckError(err)
+			}
+			flushErr := writer.Flush()
+			common.CheckError(flushErr)
 		}
 	},
 }
 
 func init() {
 	configCmd.AddCommand(configListCmd)
+
+	configListCmd.Flags().String("format", "", "Format output using a Go template.")
+	viper.BindPFlag("config.list.format", configListCmd.Flags().Lookup("format"))
+}
+
+type config struct {
+	Key                 string
+	EnvironmentVariable string
+	CurrentValue        interface{}
 }