Updates to 'faas-cli template pull'

1) Improve readability by adding canExpandTemplateData() function, which
returns an enum telling what to do with the data found in the zip
archive.
2) Add function data to ARMHF directories in template/ dir
3) More descriptive naming for test array in language_template_test.go
and checkLanguage() function changed to templateFolderExists()

Signed-off-by: Eric Stoekl <ems5311@gmail.com>

commands/fetch_templates.go

@@ -25,6 +25,15 @@ const (
 	rootLanguageDirSplitCount = 3
 )
 
+type ExtractAction int
+
+const (
+	ShouldExtractData ExtractAction = iota
+	NewTemplateFound
+	DirectoryAlreadyExists
+	SkipWritingData
+)
+
 // fetchTemplates fetch code templates from GitHub master zip file.
 func fetchTemplates(templateURL string, overwrite bool) error {
 
@@ -72,53 +81,48 @@ func expandTemplatesFromZip(archive string, overwrite bool) ([]string, []string,
 
 	for _, z := range zipFile.File {
 		var rc io.ReadCloser
-		var isDirectory bool
 
 		relativePath := z.Name[strings.Index(z.Name, "/")+1:]
 		if strings.Index(relativePath, "template/") != 0 {
 			// Process only directories inside "template" at root
 			continue
 		}
 
-		if pathSplit := strings.Split(relativePath, "/"); len(pathSplit) > 2 {
-			language := pathSplit[1]
+		action, language, isDirectory := canExpandTemplateData(availableLanguages, relativePath)
 
-			// We know that this path is a directory if the last character is a "/"
-			isDirectory = relativePath[len(relativePath)-1:] == "/"
+		var expandFromZip bool
 
-			// Check if this is the root directory for a language (at ./template/lang)
-			if len(pathSplit) == rootLanguageDirSplitCount && isDirectory {
-				// template/language/
+		switch action {
 
-				if !canWriteLanguage(&availableLanguages, language, overwrite) {
-					existingLanguages = append(existingLanguages, language)
-					continue
-				}
-				fetchedLanguages = append(fetchedLanguages, language)
-			} else {
-				// template/language/*
+		case ShouldExtractData:
+			expandFromZip = true
+		case NewTemplateFound:
+			expandFromZip = true
+			fetchedLanguages = append(fetchedLanguages, language)
+		case DirectoryAlreadyExists:
+			expandFromZip = false
+			existingLanguages = append(existingLanguages, language)
+		case SkipWritingData:
+			expandFromZip = false
+		default:
+			return nil, nil, errors.New(fmt.Sprintf("Don't know what to do when extracting zip: %s", archive))
 
-				if !canWriteLanguage(&availableLanguages, language, overwrite) {
-					continue
-				}
-			}
-		} else {
-			// template/
-			continue
 		}
 
-		if rc, err = z.Open(); err != nil {
-			break
-		}
+		if expandFromZip {
+			if rc, err = z.Open(); err != nil {
+				break
+			}
 
-		if err = createPath(relativePath, z.Mode()); err != nil {
-			break
-		}
+			if err = createPath(relativePath, z.Mode()); err != nil {
+				break
+			}
 
-		// If relativePath is just a directory, then skip expanding it.
-		if len(relativePath) > 1 && !isDirectory {
-			if err = writeFile(rc, z.UncompressedSize64, relativePath, z.Mode()); err != nil {
-				return nil, nil, err
+			// If relativePath is just a directory, then skip expanding it.
+			if len(relativePath) > 1 && !isDirectory {
+				if err = writeFile(rc, z.UncompressedSize64, relativePath, z.Mode()); err != nil {
+					return nil, nil, err
+				}
 			}
 		}
 	}
@@ -127,6 +131,33 @@ func expandTemplatesFromZip(archive string, overwrite bool) ([]string, []string,
 	return existingLanguages, fetchedLanguages, nil
 }
 
+// canExpandTemplateData() takes the map of available languages, and the
+// path to a file in the zip archive. Returns what we should do with the file
+// in form of ExtractAction enum, the language name, and whether it is a directory
+func canExpandTemplateData(availableLanguages map[string]bool, relativePath string) (ExtractAction, string, bool) {
+	if pathSplit := strings.Split(relativePath, "/"); len(pathSplit) > 2 {
+		language := pathSplit[1]
+
+		// We know that this path is a directory if the last character is a "/"
+		isDirectory := relativePath[len(relativePath)-1:] == "/"
+
+		// Check if this is the root directory for a language (at ./template/lang)
+		if len(pathSplit) == rootLanguageDirSplitCount && isDirectory {
+			if !canWriteLanguage(availableLanguages, language, overwrite) {
+				return DirectoryAlreadyExists, language, isDirectory
+			}
+			return NewTemplateFound, language, isDirectory
+		} else {
+			if !canWriteLanguage(availableLanguages, language, overwrite) {
+				return SkipWritingData, language, isDirectory
+			}
+			return ShouldExtractData, language, isDirectory
+		}
+	}
+	// template/
+	return SkipWritingData, "", true
+}
+
 // removeArchive removes the given file
 func removeArchive(archive string) error {
 	log.Printf("Cleaning up zip file...")
@@ -208,21 +239,21 @@ func createPath(relativePath string, perms os.FileMode) error {
 // canWriteLanguage() tells whether the language can be expanded from the zip or not.
 // availableLanguages map keeps track of which languages we know to be okay to copy.
 // overwrite flag will allow to force copy the language template
-func canWriteLanguage(availableLanguages *map[string]bool, language string, overwrite bool) bool {
+func canWriteLanguage(availableLanguages map[string]bool, language string, overwrite bool) bool {
 	canWrite := false
 	if availableLanguages != nil && len(language) > 0 {
-		if _, found := (*availableLanguages)[language]; found {
-			return (*availableLanguages)[language]
+		if _, found := availableLanguages[language]; found {
+			return availableLanguages[language]
 		}
-		canWrite = checkLanguage(language, overwrite)
-		(*availableLanguages)[language] = canWrite
+		canWrite = templateFolderExists(language, overwrite)
+		availableLanguages[language] = canWrite
 	}
 
 	return canWrite
 }
 
 // Takes a language input (e.g. "node"), tells whether or not it is OK to download
-func checkLanguage(language string, overwrite bool) bool {
+func templateFolderExists(language string, overwrite bool) bool {
 	dir := templateDirectory + language
 	if _, err := os.Stat(dir); err == nil && !overwrite {
 		// The directory template/language/ exists

stack/language_template_test.go

@@ -10,7 +10,7 @@ import (
 )
 
 func Test_ParseYAMLDataForLanguageTemplate(t *testing.T) {
-	dataProvider := []struct {
+	langTemplateTest := []struct {
 		Input    string
 		Expected *LanguageTemplate
 	}{
@@ -42,7 +42,7 @@ fprocess: python index.py
 		},
 	}
 
-	for k, i := range dataProvider {
+	for k, i := range langTemplateTest {
 		t.Run(fmt.Sprintf("%d", k), func(t *testing.T) {
 			if actual, err := ParseYAMLDataForLanguageTemplate([]byte(i.Input)); err != nil {
 				t.Errorf("test failed, %s", err)

template/go-armhf/function/handler.go

@@ -0,0 +1,10 @@
+package function
+
+import (
+	"fmt"
+)
+
+// Handle a serverless request
+func Handle(req []byte) string {
+	return fmt.Sprintf("Hello, Go. You said: %s", string(req))
+}

template/go-armhf/main.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+
+	"handler/function"
+)
+
+func main() {
+	input, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		log.Fatalf("Unable to read standard input: %s", err.Error())
+	}
+
+	fmt.Println(function.Handle(input))
+}

template/node-armhf/build.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+echo "Building functions/base:node-6.9.1-alpine"
+docker build -t functions/base:node-6.9.1-alpine .
+

template/node-armhf/function/handler.js

@@ -0,0 +1,5 @@
+"use strict"
+
+module.exports = (context, callback) => {
+    callback(undefined, {status: "done"});
+}

template/node-armhf/function/package.json

@@ -0,0 +1,12 @@
+{
+  "name": "function",
+  "version": "1.0.0",
+  "description": "",
+  "main": "handler.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC"
+}

template/node-armhf/index.js

@@ -0,0 +1,31 @@
+// Copyright (c) Alex Ellis 2017. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+"use strict"
+
+let getStdin = require('get-stdin');
+
+let handler = require('./function/handler');
+
+getStdin().then(val => {
+    handler(val, (err, res) => {
+        if (err) {
+            return console.error(err);
+        }
+        if(isArray(res) || isObject(res)) {
+            console.log(JSON.stringify(res));
+        } else {
+            process.stdout.write(res);
+        }
+    });
+}).catch(e => {
+    console.error(e.stack);
+});
+
+let isArray = (a) => {
+    return (!!a) && (a.constructor === Array);
+};
+
+let isObject = (a) => {
+    return (!!a) && (a.constructor === Object);
+};

template/node-armhf/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "NodejsBase",
+  "version": "1.0.0",
+  "description": "",
+  "main": "faas_index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "get-stdin": "^5.0.1"
+  }
+}

template/python-armhf/function/handler.py

@@ -0,0 +1,2 @@
+def handle(st):
+    print(st)

template/python-armhf/index.py

@@ -0,0 +1,15 @@
+# Copyright (c) Alex Ellis 2017. All rights reserved.
+# Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+import sys
+from function import handler
+
+def get_stdin():
+    buf = ""
+    for line in sys.stdin:
+        buf = buf + line
+    return buf
+
+if(__name__ == "__main__"):
+    st = get_stdin()
+    handler.handle(st)