Readme file

.gitignore

@@ -0,0 +1,9 @@
+*.tf
+.DS_Store
+.DS_Store?
+*.swp
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json

.travis.yml

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+language: go
+go:
+  - 1.9
+# Don't email me the results of the test runs.
+notifications:
+  email: false
+before_script:
+  - go get github.com/golang/lint/golint                        # Linter
+
+script:
+  - go test -v -race ./...                   # Run all the tests with the race detector enabled
+  - go vet ./...                             # go vet is the official Go static analyzer
+  - golint -set_exit_status $(go list ./...) # one last linter

README.md

@@ -1,2 +1,76 @@
 # terraform-variables-generator
-Simple Tool for Generate Variables file from Terraform Configuration
+
+Simple Tool for Generate Variables file from Terraform Configuration. It will find all *.tf files in current directory, and generate varibales.tf file, if you already have this file, it will ask to override it.
+
+## Build
+
+```bash
+go build .
+```
+
+## Usage
+
+```bash
+./terraform-variables-generator
+```
+
+It will find all *.tf files in current directory, and generate varibales.tf file, if you already have this file, it will ask to override it.
+
+### Example
+
+```text
+resource "aws_vpc" "vpc" {
+  cidr_block           = "${var.cidr}"
+  enable_dns_hostnames = "${var.enable_dns_hostnames}"
+  enable_dns_support   = "${var.enable_dns_support}"
+
+  tags {
+    Name = "${var.name}"
+  }
+}
+
+resource "aws_internet_gateway" "vpc" {
+  vpc_id = "${aws_vpc.vpc.id}"
+
+  tags {
+    Name = "${var.name}-igw"
+  }
+}
+```
+
+ Will generate
+
+ ```text
+ variable "ami" {
+   description  = ""
+}
+
+variable "instance_type" {
+   description  = ""
+}
+
+variable "cidr" {
+   description  = ""
+}
+
+variable "enable_dns_hostnames" {
+   description  = ""
+}
+
+variable "enable_dns_support" {
+   description  = ""
+}
+
+variable "name" {
+   description  = ""
+}
+ ```
+
+## Tests
+
+Run tests and linter
+
+```bash
+go test -v -race ./...
+golint -set_exit_status $(go list ./...)
+```

configuration.mock

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+//Mock Terraform Configuration File
+resource "aws_eip" "nat" {
+  vpc   = true
+  count = "${length(var.public_subnets)}"
+}
+
+resource "aws_nat_gateway" "nat" {
+  allocation_id = "${element(aws_eip.nat.*.id, count.index)}"
+  subnet_id     = "${element(aws_subnet.public.*.id, count.index)}"
+  count         = "${length(var.public_subnets)}"
+}

file_utils.go

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+package main
+
+import (
+	"os"
+	"path/filepath"
+
+	log "github.com/sirupsen/logrus"
+)
+
+func getAllFiles(ext string) ([]string, error) {
+	dir, err := os.Getwd()
+	checkError(err)
+	var files []string
+	log.Infof("Finding files in %q directory", dir)
+	files, err = filepath.Glob(ext)
+	checkError(err)
+
+	if len(files) == 0 {
+		log.Infof("No files with %q extensions found in %q", ext, dir)
+	}
+	return files, nil
+}
+
+func fileExists(name string) bool {
+	if _, err := os.Stat(name); err == nil {
+		return true
+	}
+	return false
+}

generator.go

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+package main
+
+import (
+	"bufio"
+	"html/template"
+	"os"
+	"strings"
+	"sync"
+
+	log "github.com/sirupsen/logrus"
+)
+
+var replacer *strings.Replacer
+var varPrefix = "var."
+var tfFileExt = "*.tf"
+
+var dstFile = "./variables.tf"
+var varTemplate = template.Must(template.New("var_file").Parse(`{{range .}}
+variable "{{ . }}" {
+   description  = ""
+}
+ {{end}}
+`))
+
+func init() {
+	replacer = strings.NewReplacer(":", ".",
+		"]", "",
+		"}", "",
+		"{", "",
+		"\"", "",
+		")", "",
+		"(", "",
+		"[", "",
+		",", "",
+		"var.", "",
+		" ", "",
+	)
+}
+func main() {
+	if fileExists(dstFile) {
+		userPromt()
+	}
+
+	tfFiles, err := getAllFiles(tfFileExt)
+	if len(tfFiles) == 0 {
+		log.Warn("No terraform files to proceed, exiting")
+		os.Exit(0)
+	}
+	checkError(err)
+	var wg sync.WaitGroup
+	messages := make(chan string)
+	wg.Add(len(tfFiles))
+	t := &terraformVars{}
+
+	for _, file := range tfFiles {
+		go func(file string) {
+			defer wg.Done()
+			fileHandle, _ := os.Open(file)
+			defer fileHandle.Close()
+			fileScanner := bufio.NewScanner(fileHandle)
+			for fileScanner.Scan() {
+				messages <- fileScanner.Text()
+			}
+		}(file)
+	}
+	go func() {
+		for text := range messages {
+			t.matchVarPref(text, varPrefix)
+		}
+	}()
+	wg.Wait()
+	f, err := os.Create(dstFile)
+	checkError(err)
+
+	err = varTemplate.Execute(f, t.Variables)
+	checkError(err)
+	log.Infof("Variables are generated to %q file", dstFile)
+
+}

generator_test.go

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+package main
+
+import (
+	"bufio"
+	"os"
+	"testing"
+)
+
+var mockFile = "tf_configuration.mock"
+var testExtFile = "*.mock"
+
+func TestContainsElement(t *testing.T) {
+	testSlice := []string{"Terraform", "Puppet", "Ansible"}
+	if containsElement(testSlice, "Chef") {
+		t.Error("Should return false, but return true")
+	}
+}
+
+func TestGetAllFiles(t *testing.T) {
+	files, err := getAllFiles(testExtFile)
+	checkError(err)
+	if len(files) == 0 {
+		t.Error("Should found at least one file")
+	}
+}
+
+func TestMatchVariable(t *testing.T) {
+	ter := &terraformVars{}
+	var messages []string
+
+	file, err := getAllFiles(testExtFile)
+	checkError(err)
+
+	fileHandle, _ := os.Open(file[0])
+	defer fileHandle.Close()
+
+	fileScanner := bufio.NewScanner(fileHandle)
+	for fileScanner.Scan() {
+		messages = append(messages, fileScanner.Text())
+	}
+	for _, text := range messages {
+		ter.matchVarPref(text, varPrefix)
+	}
+	if len(ter.Variables) != 1 {
+		t.Errorf("Should return one variable. but returned %d", len(ter.Variables))
+	}
+
+}

helpers.go

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+package main
+
+import (
+	"fmt"
+	"os"
+
+	log "github.com/sirupsen/logrus"
+)
+
+func checkError(e error) {
+	if e != nil {
+		log.Fatal(e)
+	}
+}
+
+func containsElement(slice []string, value string) bool {
+	if len(slice) == 0 {
+		return false
+	}
+	for _, s := range slice {
+		if value == s {
+			return true
+		}
+	}
+	return false
+}
+
+func userPromt() {
+	var response string
+	log.Warnf("File %q already exists, type yes if you want replace", dstFile)
+	fmt.Print("-> ")
+	_, err := fmt.Scanln(&response)
+	checkError(err)
+	if response != "yes" {
+		os.Exit(0)
+	}
+}

terraform.go

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+package main
+
+import (
+	"regexp"
+	"strings"
+)
+
+type terraformVars struct {
+	Variables []string
+}
+
+func (t *terraformVars) matchVarPref(row, varPrefix string) {
+	if strings.Contains(row, varPrefix) {
+		pattern := regexp.MustCompile(`var.([a-z?_]+)`)
+		match := pattern.FindAllStringSubmatch(row, 1)
+		if len(match) != 0 {
+			res := replacer.Replace(match[0][0])
+			if !containsElement(t.Variables, res) {
+				t.Variables = append(t.Variables, res)
+			}
+		}
+	}
+}