Refactor template format

README.md

@@ -45,9 +45,9 @@ Devices currently present on Arduino IoT Cloud can be retrieved by using this co
 
 Things can be created starting from a template or by cloning another thing.
 
-Create a thing from a thing template. The name parameter is optional. If it is provided then it overrides the name retrieved from the template:
+Create a thing from a thing template. Supported template formats are JSON and YAML. The name parameter is optional. If it is provided then it overrides the name retrieved from the template:
 
-`$ iot-cloud-cli thing create --name <thingName> --template <template.json>`
+`$ iot-cloud-cli thing create --name <thingName> --template <template.(json|yaml)>`
 
 Create a thing by cloning another thing, here the *name is mandatory*:
 
@@ -72,9 +72,9 @@ Delete a thing with the following command:
 
 `$ iot-cloud-cli thing delete --device-id <deviceID>`
 
-Extract a template from an existing thing:
+Extract a template from an existing thing. The template can be saved in two formats: json or yaml. The default format is yaml:
 
-`$ iot-cloud-cli thing extract --id <thingID> --outfile <templateFile.json>`
+`$ iot-cloud-cli thing extract --id <thingID> --outfile <templateFile> --format <yaml|json>`
 
 Bind a thing to an existing device:
 

cli/thing/create.go

@@ -20,7 +20,13 @@ func initCreateCommand() *cobra.Command {
 		RunE:  runCreateCommand,
 	}
 	createCommand.Flags().StringVarP(&createFlags.name, "name", "n", "", "Thing name")
-	createCommand.Flags().StringVarP(&createFlags.template, "template", "t", "", "File containing a thing template")
+	createCommand.Flags().StringVarP(
+		&createFlags.template,
+		"template",
+		"t",
+		"",
+		"File containing a thing template, JSON and YAML format are supported",
+	)
 	createCommand.MarkFlagRequired("template")
 	return createCommand
 }

cli/thing/extract.go

@@ -10,6 +10,7 @@ import (
 var extractFlags struct {
 	id      string
 	outfile string
+	format  string
 }
 
 func initExtractCommand() *cobra.Command {
@@ -21,6 +22,13 @@ func initExtractCommand() *cobra.Command {
 	}
 	extractCommand.Flags().StringVarP(&extractFlags.id, "id", "i", "", "Thing ID")
 	extractCommand.Flags().StringVarP(&extractFlags.outfile, "outfile", "o", "", "Template file destination path")
+	extractCommand.Flags().StringVar(
+		&extractFlags.format,
+		"format",
+		"yaml",
+		"Format of template file, can be {json|yaml}. Default is 'yaml'",
+	)
+
 	extractCommand.MarkFlagRequired("id")
 	return extractCommand
 }
@@ -29,7 +37,8 @@ func runExtractCommand(cmd *cobra.Command, args []string) error {
 	fmt.Printf("Extracting template from thing %s\n", extractFlags.id)
 
 	params := &thing.ExtractParams{
-		ID: extractFlags.id,
+		ID:     extractFlags.id,
+		Format: extractFlags.format,
 	}
 	if extractFlags.outfile != "" {
 		params.Outfile = &extractFlags.outfile

command/thing/create.go

@@ -10,6 +10,7 @@ import (
 	iotclient "github.com/arduino/iot-client-go"
 	"github.com/arduino/iot-cloud-cli/internal/config"
 	"github.com/arduino/iot-cloud-cli/internal/iot"
+	"gopkg.in/yaml.v3"
 )
 
 // CreateParams contains the parameters needed to create a new thing.
@@ -67,9 +68,12 @@ func loadTemplate(file string) (*iotclient.Thing, error) {
 	}
 
 	template := make(map[string]interface{})
-	err = json.Unmarshal([]byte(templateBytes), &template)
-	if err != nil {
-		return nil, fmt.Errorf("%s: %w", "reading template file: template not valid: ", err)
+
+	// Extract template trying all the supported formats: json and yaml
+	if err = json.Unmarshal([]byte(templateBytes), &template); err != nil {
+		if err = yaml.Unmarshal([]byte(templateBytes), &template); err != nil {
+			return nil, errors.New("reading template file: template format is not valid")
+		}
 	}
 
 	// Adapt thing template to thing structure

command/thing/extract.go

@@ -2,26 +2,36 @@ package thing
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
+	"strings"
 
 	iotclient "github.com/arduino/iot-client-go"
 	"github.com/arduino/iot-cloud-cli/internal/config"
 	"github.com/arduino/iot-cloud-cli/internal/iot"
+	"gopkg.in/yaml.v3"
 )
 
 // ExtractParams contains the parameters needed to
 // extract a thing from Arduino IoT Cloud and save it on local storage.
+// Format determines the file format of the template ("json" or "yaml")
 // Output indicates the destination path of the extraction.
 type ExtractParams struct {
 	ID      string
+	Format  string
 	Outfile *string
 }
 
 // Extract command is used to extract a thing template
 // from a thing on Arduino IoT Cloud.
 func Extract(params *ExtractParams) error {
+	params.Format = strings.ToLower(params.Format)
+	if params.Format != "json" && params.Format != "yaml" {
+		return errors.New("format is not valid: only 'json' and 'yaml' are supported")
+	}
+
 	conf, err := config.Retrieve()
 	if err != nil {
 		return err
@@ -42,23 +52,19 @@ func Extract(params *ExtractParams) error {
 		return err
 	}
 
-	if params.Outfile == nil {
-		outfile := thing.Name + "-template.json"
-		params.Outfile = &outfile
-	}
-	err = ioutil.WriteFile(*params.Outfile, template, os.FileMode(0644))
+	err = templateToFile(template, params)
 	if err != nil {
-		err = fmt.Errorf("%s: %w", "cannot write outfile: ", err)
 		return err
 	}
 
 	return nil
 }
 
-func templateFromThing(thing *iotclient.ArduinoThing) ([]byte, error) {
+func templateFromThing(thing *iotclient.ArduinoThing) (map[string]interface{}, error) {
 	template := make(map[string]interface{})
 	template["name"] = thing.Name
 
+	// Extract template from thing structure
 	var props []map[string]interface{}
 	for _, p := range thing.Properties {
 		prop := make(map[string]interface{})
@@ -72,11 +78,42 @@ func templateFromThing(thing *iotclient.ArduinoThing) ([]byte, error) {
 	}
 	template["variables"] = props
 
-	// Extract json template from thing structure
-	file, err := json.MarshalIndent(template, "", "    ")
+	return template, nil
+}
+
+func templateToFile(template map[string]interface{}, params *ExtractParams) error {
+	var file []byte
+	var err error
+
+	if params.Format == "json" {
+		file, err = json.MarshalIndent(template, "", "    ")
+		if err != nil {
+			return fmt.Errorf("%s: %w", "thing marshal failure: ", err)
+		}
+
+	} else if params.Format == "yaml" {
+		file, err = yaml.Marshal(template)
+		if err != nil {
+			return fmt.Errorf("%s: %w", "thing marshal failure: ", err)
+		}
+
+	} else {
+		return errors.New("format is not valid: only 'json' and 'yaml' are supported")
+	}
+
+	if params.Outfile == nil {
+		name, ok := template["name"].(string)
+		if name == "" || !ok {
+			return errors.New("thing template does not have a valid name")
+		}
+		outfile := name + "." + params.Format
+		params.Outfile = &outfile
+	}
+
+	err = ioutil.WriteFile(*params.Outfile, file, os.FileMode(0644))
 	if err != nil {
-		err = fmt.Errorf("%s: %w", "thing marshal failure: ", err)
-		return nil, err
+		return fmt.Errorf("%s: %w", "cannot write outfile: ", err)
 	}
-	return file, nil
+
+	return nil
 }

go.mod

@@ -20,4 +20,5 @@ require (
 	google.golang.org/genproto v0.0.0-20210504143626-3b2ad6ccc450 // indirect
 	google.golang.org/grpc v1.39.0
 	google.golang.org/protobuf v1.27.1 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c
 )