Feat: support OpenTofu (#185)

* Feat: support OpenTofu

* fix pipeline

* more changes

* use opentofu

* added arg default-to-terraform

.github/workflows/ci.yml

@@ -11,9 +11,9 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
-      - name: Install Go
-        uses: actions/setup-go@v4
+        uses: actions/checkout@v4
+      - name: Set up Go
+        uses: actions/setup-go@v5
         with:
           go-version: 1.21
       - name: Go fmt
@@ -40,9 +40,9 @@ jobs:
 
     steps:
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Set up Go
-        uses: actions/setup-go@v4
+        uses: actions/setup-go@v5
         with:
           go-version: 1.21
         id: go
@@ -83,29 +83,52 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Set up Go
-        uses: actions/setup-go@v4
+        uses: actions/setup-go@v5
         with:
           go-version: 1.21
         id: go
       - name: Get dependencies
         run: |
           go mod tidy
       - name: Install Terraform
-        uses: hashicorp/setup-terraform@v2
+        uses: hashicorp/setup-terraform@v3
         with:
           terraform_version: 1.2.5
       - name: Print Terraform version
         run: |
           terraform --version
       - name: Install Terragrunt
-        uses: autero1/[email protected].1
+        uses: autero1/[email protected].2
         with:
-          terragrunt_version: 0.38.5
+          terragrunt_version: 0.54.22
       - name: Print Terragrunt version
         run: |
           terragrunt --version
       - name: Test
         run: |
           go test -v -run ^TestTerragruntWithCache$
+  
+  opentofu-integration-tests:
+    name: OpenTofu Integration Tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v4
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: 1.21
+        id: go
+      - name: Get dependencies
+        run: |
+          go mod tidy
+      - name: Install OpenTofu
+        uses: opentofu/setup-opentofu@v1
+      - name: Print OpenTofu version
+        run: |
+          tofu --version
+      - name: Test
+        run: |
+          go test -v -run ^TestOpenTofu$

README.md

@@ -9,21 +9,21 @@
 
 ## What?
 
-Terratag is a CLI tool allowing for tags or labels to be applied across an entire set of Terraform files. Terratag will apply tags or labels to any AWS, GCP and Azure resources.
+Terratag is a CLI tool allowing for tags or labels to be applied across an entire set of OpenTofu/Terraform files. Terratag will apply tags or labels to any AWS, GCP and Azure resources.
 
 ### Terratag in action
 
 ![](https://assets.website-files.com/5dc3f52851595b160ba99670/5f62090d2d532ca35e143133_terratag.gif)
 
 ## Why?
 
-Maintaining tags across your application is hard, especially when done manually. Terratag enables you to easily add tags to your existing IaC and benefit from some cross-resource tag applications you wish you had thought of when you had just started writing your Terraform, saving you tons of time and making future updates easy. [Read more](https://d1.awsstatic.com/whitepapers/aws-tagging-best-practices.pdf) on why tagging is important.
+Maintaining tags across your application is hard, especially when done manually. Terratag enables you to easily add tags to your existing IaC and benefit from some cross-resource tag applications you wish you had thought of when you had just started writing your OpenTofu/Terraform, saving you tons of time and making future updates easy. [Read more](https://d1.awsstatic.com/whitepapers/aws-tagging-best-practices.pdf) on why tagging is important.
 
 ## How?
 
 ### Prerequisites
 
-- Terraform 0.12 through 1.x
+- OpenTofu 1.x or Terraform 0.12 through 1.x.
 
 ### Usage
 
@@ -35,7 +35,11 @@ Maintaining tags across your application is hard, especially when done manually.
 
    Or download the latest [release binary](https://github.com/env0/terratag/releases) .
 
-1. Initialize Terraform modules to get provider schema and pull child modules:
+1. Initialize Opentofu/Terraform modules to get provider schema and pull child modules:
+   ```bash
+    tofu init
+   ```
+
    ```bash
     terraform init
    ```
@@ -51,14 +55,6 @@ Maintaining tags across your application is hard, especially when done manually.
     terratag -dir=foo/bar -tags="environment_id=prod,some-tag=value"
    ```
 
-   Terratag supports the following arguments:
-
-   - `-dir` - optional, the directory to recursively search for any `.tf` file and try to terratag it.
-   - `-tags` - tags, as valid JSON (NOT HCL) or a comma seperated list of key=value.
-   - `-skipTerratagFiles` - optional. Default to `true`. Skips any previously tagged - (files with `terratag.tf` suffix)
-   - `-filter` - optional. Only apply tags to the selected resource types (regex)
-   - `-skip` - optional. Skip applying tags to the selected resource types (regex)
-
 ### Example Output
 
 #### Before Terratag
@@ -168,12 +164,13 @@ locals {
 
 ### Optional CLI flags
 
-- `-dir=<path>` - defaults to `.`. Sets the terraform folder to tag `.tf` files in
+- `-dir=<path>` - defaults to `.`. Sets the opentofu/terraform folder to tag `.tf` files in
 - `-skipTerratagFiles=false` - Dont skip processing `*.terratag.tf` files (when running terratag a second time for the same directory)
-- `-verbose=true` - Turn on verbose logging
 - `-rename=false` - Instead of replacing files named `<basename>.tf` with `<basename>.terratag.tf`, keep the original filename
 - `-filter=<regular expression>` - defaults to `.*`. Only apply tags to the resource types matched by the regular expression
-- `-type=<terraform or terragrunt>` - defaults to `terraform`. If `terragrunt` is used, tags the files under `.terragrunt-cache` folder. Note: if Terragrunt does not create a `.terragrunt-cache` folder, use the default or omit.
+- `-type=<terraform or terragrunt>` - defaults to `terraform` (and `opentofu`). If `terragrunt` is used, tags the files under `.terragrunt-cache` folder. Note: if Terragrunt does not create a `.terragrunt-cache` folder, use the default or omit.
+- `-verbose` - Turn on verbose logging
+- `-default-to-terraform` By default uses OpenTofu (if installed), if set will use Terraform even when Opentofu is installed
 
 Setting options via enviroment variables is also supported. CLI flags have a precedence over envrionment variables.
 
@@ -186,6 +183,7 @@ TERRATAG_SKIP
 TERRATAG_VERBOSE
 TERRATAG_RENAME
 TERRATAG_TYPE
+TERRATAG_DEFAULT_TO_TERRAFORM
 ```
 
 ##### See more samples [here](https://github.com/env0/terratag/tree/master/test/fixture)

cli/args.go

@@ -20,6 +20,7 @@ type Args struct {
 	Verbose             bool
 	Rename              bool
 	Version             bool
+	DefaultToTerraform  bool
 }
 
 func validate(args Args) error {
@@ -48,6 +49,7 @@ func InitArgs() (Args, error) {
 	fs.BoolVar(&args.Rename, "rename", true, "Keep the original filename or replace it with <basename>.terratag.tf")
 	fs.StringVar(&args.Type, "type", string(common.Terraform), "The IAC type. Valid values: terraform or terragrunt")
 	fs.BoolVar(&args.Version, "version", false, "Prints the version")
+	fs.BoolVar(&args.DefaultToTerraform, "default-to-terraform", false, "By default uses OpenTofu (if installed), if set will use Terraform even when Opentofu is installed")
 
 	// Set cli args based on environment variables.
 	//The command line flags have precedence over environment variables.

internal/common/common.go

@@ -22,8 +22,8 @@ type TaggingArgs struct {
 	Matches             []string
 	IsSkipTerratagFiles bool
 	Rename              bool
+	DefaultToTerraform  bool
 	IACType             IACType
-	TFVersion           Version
 }
 
 type TerratagLocal struct {

internal/convert/convert.go

@@ -15,7 +15,7 @@ import (
 	"github.com/zclconf/go-cty/cty"
 )
 
-func GetExistingTagsExpression(tokens hclwrite.Tokens, tfVersion common.Version) string {
+func GetExistingTagsExpression(tokens hclwrite.Tokens) string {
 	return stringifyExpression(tokens)
 }
 

internal/tagging/tagging.go

@@ -41,14 +41,10 @@ func TagBlock(args TagBlockArgs) (string, error) {
 
 	if hasExistingTags {
 		existingTagsKey := tag_keys.GetResourceExistingTagsKey(args.Filename, args.Block)
-		existingTagsExpression := convert.GetExistingTagsExpression(args.Terratag.Found[existingTagsKey], args.TfVersion)
+		existingTagsExpression := convert.GetExistingTagsExpression(args.Terratag.Found[existingTagsKey])
 		newTagsValue = "merge( " + existingTagsExpression + ", " + terratagAddedKey + ")"
 	}
 
-	if args.TfVersion.Major == 0 && args.TfVersion.Minor == 11 {
-		newTagsValue = "\"${" + newTagsValue + "}\""
-	}
-
 	newTagsValueTokens := ParseHclValueStringToTokens(newTagsValue)
 	args.Block.Body().SetAttributeRaw(args.TagId, newTagsValueTokens)
 
@@ -78,12 +74,11 @@ var resourceTypeToFnMap = map[string]TagResourceFn{
 }
 
 type TagBlockArgs struct {
-	Filename  string
-	Block     *hclwrite.Block
-	Tags      string
-	Terratag  common.TerratagLocal
-	TagId     string
-	TfVersion common.Version
+	Filename string
+	Block    *hclwrite.Block
+	Tags     string
+	Terratag common.TerratagLocal
+	TagId    string
 }
 
 type TagResourceFn func(args TagBlockArgs) (*Result, error)

internal/terraform/terraform.go

@@ -2,16 +2,12 @@ package terraform
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"io/fs"
 	"log"
 	"os"
-	"os/exec"
 	"path/filepath"
-	"regexp"
-	"strconv"
 	"strings"
 
 	"github.com/bmatcuk/doublestar"
@@ -20,56 +16,6 @@ import (
 	"github.com/thoas/go-funk"
 )
 
-func GetTerraformVersion() (*common.Version, error) {
-	output, err := exec.Command("terraform", "version").Output()
-	if err != nil {
-		return nil, err
-	}
-
-	outputAsString := strings.TrimSpace(string(output))
-	regularExpression := regexp.MustCompile(`Terraform v(\d+).(\d+)\.\d+`)
-	matches := regularExpression.FindStringSubmatch(outputAsString)[1:]
-
-	if matches == nil {
-		return nil, errors.New("unable to parse 'terraform version'")
-	}
-
-	majorVersion, err := getVersionPart(matches, Major)
-	if err != nil {
-		return nil, err
-	}
-	minorVersion, err := getVersionPart(matches, Minor)
-	if err != nil {
-		return nil, err
-	}
-
-	if (majorVersion == 0 && minorVersion < 11 || minorVersion > 15) || majorVersion > 1 {
-		return nil, fmt.Errorf("terratag only supports Terraform from version 0.11.x and up to 1.x.x - your version says %s", outputAsString)
-	}
-
-	return &common.Version{Major: majorVersion, Minor: minorVersion}, nil
-}
-
-type VersionPart int
-
-const (
-	Major VersionPart = iota
-	Minor
-)
-
-func (w VersionPart) EnumIndex() int {
-	return int(w)
-}
-
-func getVersionPart(parts []string, versionPart VersionPart) (int, error) {
-	version, err := strconv.Atoi(parts[versionPart])
-	if err != nil {
-		return -1, fmt.Errorf("unable to parse %s as integer", parts[versionPart])
-	}
-
-	return version, nil
-}
-
 func GetResourceType(resource hclwrite.Block) string {
 	return resource.Labels()[0]
 }

internal/tfschema/tfschema.go

@@ -54,12 +54,12 @@ type ProviderSchemas struct {
 	ProviderSchemas map[string]*ProviderSchema `json:"provider_schemas"`
 }
 
-func IsTaggable(dir string, iacType common.IACType, resource hclwrite.Block) (bool, error) {
+func IsTaggable(dir string, iacType common.IACType, defaultToTerraform bool, resource hclwrite.Block) (bool, error) {
 	var isTaggable bool
 	resourceType := terraform.GetResourceType(resource)
 
 	if providers.IsSupportedResource(resourceType) {
-		resourceSchema, err := getResourceSchema(resourceType, resource, dir, iacType)
+		resourceSchema, err := getResourceSchema(resourceType, resource, dir, iacType, defaultToTerraform)
 		if err != nil {
 			if err == ErrResourceTypeNotFound {
 				log.Print("[WARN] Skipped ", resourceType, " as it is not YET supported")
@@ -132,7 +132,7 @@ func detectProviderName(resource hclwrite.Block) (string, error) {
 	return extractProviderNameFromResourceType(terraform.GetResourceType(resource))
 }
 
-func getResourceSchema(resourceType string, resource hclwrite.Block, dir string, iacType common.IACType) (*ResourceSchema, error) {
+func getResourceSchema(resourceType string, resource hclwrite.Block, dir string, iacType common.IACType, defaultToTerraform bool) (*ResourceSchema, error) {
 	if iacType == common.Terragrunt {
 		// which mode of terragrunt it is (with or without cache folder).
 		if _, err := os.Stat(dir + "/.terragrunt-cache"); err == nil {
@@ -147,12 +147,18 @@ func getResourceSchema(resourceType string, resource hclwrite.Block, dir string,
 	if !ok {
 		providerSchemas = &ProviderSchemas{}
 
-		cmd := exec.Command("terraform", "providers", "schema", "-json")
+		// Use tofu by default (if it exists).
+		name := "terraform"
+		if _, err := exec.LookPath("tofu"); !defaultToTerraform && err == nil {
+			name = "tofu"
+		}
+
+		cmd := exec.Command(name, "providers", "schema", "-json")
 		cmd.Dir = dir
 
 		out, err := cmd.Output()
 		if err != nil {
-			return nil, fmt.Errorf("failed to execute 'terraform providers schema -json' command: %w", err)
+			return nil, fmt.Errorf("failed to execute '%s providers schema -json' command: %w", name, err)
 		}
 
 		// Output can vary between operating systems. Get the correct output line.