Bump recommended templates to the top of the file

* Introduces concept of sorting by recommended templates
* Adds filtering options to only view recommended or official
templates

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

commands/template_store_list.go

@@ -8,9 +8,11 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
+
 	"net/http"
 	"os"
+	"sort"
 	"strings"
 	"text/tabwriter"
 	"time"
@@ -27,12 +29,16 @@ const (
 var (
 	templateStoreURL string
 	inputPlatform    string
+	recommended      bool
+	official         bool
 )
 
 func init() {
 	templateStoreListCmd.Flags().BoolVarP(&verbose, "verbose", "v", false, "Shows additional language and platform")
 	templateStoreListCmd.PersistentFlags().StringVarP(&templateStoreURL, "url", "u", DefaultTemplatesStore, "Use as alternative store for templates")
 	templateStoreListCmd.Flags().StringVarP(&inputPlatform, "platform", "p", mainPlatform, "Shows the platform if the output is verbose")
+	templateStoreListCmd.Flags().BoolVarP(&recommended, "recommended", "r", false, "Shows only recommended templates")
+	templateStoreListCmd.Flags().BoolVarP(&official, "official", "o", false, "Shows only official templates")
 
 	templateStoreCmd.AddCommand(templateStoreListCmd)
 }
@@ -42,25 +48,58 @@ var templateStoreListCmd = &cobra.Command{
 	Use:     `list`,
 	Short:   `List templates from OpenFaaS organizations`,
 	Aliases: []string{"ls"},
-	Long:    `List templates from official store or from custom URL or set the environmental variable OPENFAAS_TEMPLATE_STORE_URL to be the default store location`,
+	Long: `List templates from a template store manifest file, by default the 
+official list maintained by the OpenFaaS community is used. You can override this.`,
 	Example: `  faas-cli template store list
-  faas-cli template store ls
-  faas-cli template store ls --url=https://raw.githubusercontent.com/openfaas/store/master/templates.json
+  # List only recommended templates
+  faas-cli template store list --recommended
+
+  # List only official templates
+  faas-cli template store list --official
+
+  # Override the store via a flag
+  faas-cli template store ls \
+  --url=https://raw.githubusercontent.com/openfaas/store/master/templates.json
+
+  # Specify an alternative store via environment variable
+  export OPENFAAS_TEMPLATE_STORE_URL=https://example.com/templates.json
+
+  # See additional language and platform
   faas-cli template store ls --verbose=true
-  faas-cli template store list --platform arm64`,
+
+  # Filter by platform for arm64 only
+  faas-cli template store list --platform arm64 
+`,
 	RunE: runTemplateStoreList,
 }
 
 func runTemplateStoreList(cmd *cobra.Command, args []string) error {
 	envTemplateRepoStore := os.Getenv(templateStoreURLEnvironment)
 	storeURL := getTemplateStoreURL(templateStoreURL, envTemplateRepoStore, DefaultTemplatesStore)
 
-	templatesInfo, templatesErr := getTemplateInfo(storeURL)
-	if templatesErr != nil {
-		return fmt.Errorf("error while getting templates info: %s", templatesErr)
+	templatesInfo, err := getTemplateInfo(storeURL)
+	if err != nil {
+		return fmt.Errorf("error while getting templates info: %s", err)
 	}
+	list := []TemplateInfo{}
 
-	formattedOutput := formatTemplatesOutput(templatesInfo, verbose, inputPlatform)
+	if recommended {
+		for i := 0; i < len(templatesInfo); i++ {
+			if templatesInfo[i].Recommended {
+				list = append(list, templatesInfo[i])
+			}
+		}
+	} else if official {
+		for i := 0; i < len(templatesInfo); i++ {
+			if templatesInfo[i].Official == "true" {
+				list = append(list, templatesInfo[i])
+			}
+		}
+	} else {
+		list = templatesInfo
+	}
+
+	formattedOutput := formatTemplatesOutput(list, verbose, inputPlatform)
 
 	fmt.Fprintf(cmd.OutOrStdout(), "%s", formattedOutput)
 
@@ -78,9 +117,9 @@ func getTemplateInfo(repository string) ([]TemplateInfo, error) {
 	req = req.WithContext(reqContext)
 
 	client := http.DefaultClient
-	res, clientErr := client.Do(req)
-	if clientErr != nil {
-		return nil, fmt.Errorf("error while requesting template list: %s", clientErr.Error())
+	res, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("error while requesting template list: %s", err.Error())
 	}
 
 	if res.Body == nil {
@@ -92,19 +131,37 @@ func getTemplateInfo(repository string) ([]TemplateInfo, error) {
 		return nil, fmt.Errorf("unexpected status code wanted: %d got: %d", http.StatusOK, res.StatusCode)
 	}
 
-	body, bodyErr := ioutil.ReadAll(res.Body)
-	if bodyErr != nil {
-		return nil, fmt.Errorf("error while reading data from templates body: %s", bodyErr.Error())
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, fmt.Errorf("error while reading response: %s", err.Error())
 	}
 
 	templatesInfo := []TemplateInfo{}
-	unmarshallErr := json.Unmarshal(body, &templatesInfo)
-	if unmarshallErr != nil {
-		return nil, fmt.Errorf("error while unmarshalling into templates struct: %s", unmarshallErr.Error())
+	if err := json.Unmarshal(body, &templatesInfo); err != nil {
+		return nil, fmt.Errorf("can't unmarshal text: %s", err.Error())
 	}
+
+	sortTemplates(templatesInfo)
+
 	return templatesInfo, nil
 }
 
+func sortTemplates(templatesInfo []TemplateInfo) {
+	sort.Slice(templatesInfo, func(i, j int) bool {
+		if templatesInfo[i].Recommended == templatesInfo[j].Recommended {
+			if templatesInfo[i].Official == templatesInfo[j].Official {
+				return strings.ToLower(templatesInfo[i].TemplateName) < strings.ToLower(templatesInfo[j].TemplateName)
+			} else {
+				return templatesInfo[i].Official < templatesInfo[j].Official
+			}
+		} else if templatesInfo[i].Recommended {
+			return true
+		} else {
+			return false
+		}
+	})
+}
+
 func formatTemplatesOutput(templates []TemplateInfo, verbose bool, platform string) string {
 
 	if platform != mainPlatform {
@@ -135,10 +192,17 @@ func formatTemplatesOutput(templates []TemplateInfo, verbose bool, platform stri
 
 func formatBasicOutput(lineWriter *tabwriter.Writer, templates []TemplateInfo) {
 
-	fmt.Fprintf(lineWriter, "NAME\tSOURCE\tDESCRIPTION\n")
+	fmt.Fprintf(lineWriter, "NAME\tRECOMMENDED\tDESCRIPTION\tSOURCE\n")
 	for _, template := range templates {
-		fmt.Fprintf(lineWriter, "%s\t%s\t%s\n",
+
+		recommended := "[ ]"
+		if template.Recommended {
+			recommended = "[x]"
+		}
+
+		fmt.Fprintf(lineWriter, "%s\t%s\t%s\t%s\n",
 			template.TemplateName,
+			recommended,
 			template.Source,
 			template.Description)
 	}
@@ -166,6 +230,7 @@ type TemplateInfo struct {
 	Description  string `json:"description"`
 	Repository   string `json:"repo"`
 	Official     string `json:"official"`
+	Recommended  bool   `json:"recommended"`
 }
 
 func filterTemplate(templates []TemplateInfo, platform string) []TemplateInfo {