feat: terraform variables added to input (#165)

Input can override template vars, implementing the equivalent of '-var'
in terraform.

Author: Emyrk

internal/verify/exec.go

@@ -56,14 +56,15 @@ func (e WorkingExecutable) Init(ctx context.Context) error {
 	return e.TF.Init(ctx, tfexec.Upgrade(true))
 }
 
-func (e WorkingExecutable) Plan(ctx context.Context, outPath string) (bool, error) {
-	changes, err := e.TF.Plan(ctx, tfexec.Out(outPath))
+func (e WorkingExecutable) Plan(ctx context.Context, outPath string, opts ...tfexec.PlanOption) (bool, error) {
+	opts = append(opts, tfexec.Out(outPath))
+	changes, err := e.TF.Plan(ctx, opts...)
 	return changes, err
 }
 
-func (e WorkingExecutable) Apply(ctx context.Context) ([]byte, error) {
+func (e WorkingExecutable) Apply(ctx context.Context, opts ...tfexec.ApplyOption) ([]byte, error) {
 	var out bytes.Buffer
-	err := e.TF.ApplyJSON(ctx, &out)
+	err := e.TF.ApplyJSON(ctx, &out, opts...)
 	return out.Bytes(), err
 }
 

preview.go

@@ -6,14 +6,14 @@ import (
 	"fmt"
 	"io/fs"
 	"log/slog"
-	"path/filepath"
 
 	"github.com/aquasecurity/trivy/pkg/iac/scanners/terraform/parser"
 	"github.com/hashicorp/hcl/v2"
 	"github.com/zclconf/go-cty/cty"
 	ctyjson "github.com/zclconf/go-cty/cty/json"
 
 	"github.com/coder/preview/hclext"
+	"github.com/coder/preview/tfvars"
 	"github.com/coder/preview/types"
 )
 
@@ -26,6 +26,9 @@ type Input struct {
 	ParameterValues map[string]string
 	Owner           types.WorkspaceOwner
 	Logger          *slog.Logger
+	// TFVars will override any variables set in '.tfvars' files.
+	// The value set must be a cty.Value, as the type can be anything.
+	TFVars map[string]cty.Value
 }
 
 type Output struct {
@@ -80,12 +83,7 @@ func Preview(ctx context.Context, input Input, dir fs.FS) (output *Output, diagn
 		}
 	}()
 
-	// TODO: Fix logging. There is no way to pass in an instanced logger to
-	//   the parser.
-	// slog.SetLogLoggerLevel(slog.LevelDebug)
-	// slog.SetDefault(slog.New(log.NewHandler(os.Stderr, nil)))
-
-	varFiles, err := tfVarFiles("", dir)
+	varFiles, err := tfvars.TFVarFiles("", dir)
 	if err != nil {
 		return nil, hcl.Diagnostics{
 			{
@@ -96,6 +94,17 @@ func Preview(ctx context.Context, input Input, dir fs.FS) (output *Output, diagn
 		}
 	}
 
+	variableValues, err := tfvars.LoadTFVars(dir, varFiles)
+	if err != nil {
+		return nil, hcl.Diagnostics{
+			{
+				Severity: hcl.DiagError,
+				Summary:  "Failed to load tfvars from files",
+				Detail:   err.Error(),
+			},
+		}
+	}
+
 	planHook, err := planJSONHook(dir, input)
 	if err != nil {
 		return nil, hcl.Diagnostics{
@@ -123,17 +132,24 @@ func Preview(ctx context.Context, input Input, dir fs.FS) (output *Output, diagn
 		logger = slog.New(slog.DiscardHandler)
 	}
 
+	// Override with user-supplied variables
+	for k, v := range input.TFVars {
+		variableValues[k] = v
+	}
+
 	// moduleSource is "" for a local module
 	p := parser.New(dir, "",
 		parser.OptionWithLogger(logger),
 		parser.OptionStopOnHCLError(false),
 		parser.OptionWithDownloads(false),
 		parser.OptionWithSkipCachedModules(true),
-		parser.OptionWithTFVarsPaths(varFiles...),
 		parser.OptionWithEvalHook(planHook),
 		parser.OptionWithEvalHook(ownerHook),
 		parser.OptionWithWorkingDirectoryPath("/"),
 		parser.OptionWithEvalHook(parameterContextsEvalHook(input)),
+		// 'OptionsWithTfVars' cannot be set with 'OptionWithTFVarsPaths'. So load the
+		// tfvars from the files ourselves and merge with the user-supplied tf vars.
+		parser.OptionsWithTfVars(variableValues),
 	)
 
 	err = p.ParseFS(ctx, ".")
@@ -179,33 +195,3 @@ func (i Input) RichParameterValue(key string) (string, bool) {
 	p, ok := i.ParameterValues[key]
 	return p, ok
 }
-
-// tfVarFiles extracts any .tfvars files from the given directory.
-// TODO: Test nested directories and how that should behave.
-func tfVarFiles(path string, dir fs.FS) ([]string, error) {
-	dp := "."
-	entries, err := fs.ReadDir(dir, dp)
-	if err != nil {
-		return nil, fmt.Errorf("read dir %q: %w", dp, err)
-	}
-
-	files := make([]string, 0)
-	for _, entry := range entries {
-		if entry.IsDir() {
-			subD, err := fs.Sub(dir, entry.Name())
-			if err != nil {
-				return nil, fmt.Errorf("sub dir %q: %w", entry.Name(), err)
-			}
-			newFiles, err := tfVarFiles(filepath.Join(path, entry.Name()), subD)
-			if err != nil {
-				return nil, err
-			}
-			files = append(files, newFiles...)
-		}
-
-		if filepath.Ext(entry.Name()) == ".tfvars" {
-			files = append(files, filepath.Join(path, entry.Name()))
-		}
-	}
-	return files, nil
-}

preview_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/hashicorp/hcl/v2"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"github.com/zclconf/go-cty/cty"
 
 	"github.com/coder/preview"
 	"github.com/coder/preview/types"
@@ -471,6 +472,37 @@ func Test_Extract(t *testing.T) {
 					optNames("GoLand 2024.3", "IntelliJ IDEA Ultimate 2024.3", "PyCharm Professional 2024.3"),
 			},
 		},
+		{
+			name:    "tfvars_from_file",
+			dir:     "tfvars",
+			expTags: map[string]string{},
+			input: preview.Input{
+				ParameterValues: map[string]string{},
+			},
+			unknownTags: []string{},
+			params: map[string]assertParam{
+				"variable_values": ap().
+					def("alex").optVals("alex", "bob", "claire", "jason"),
+			},
+		},
+		{
+			name:    "tfvars_from_input",
+			dir:     "tfvars",
+			expTags: map[string]string{},
+			input: preview.Input{
+				ParameterValues: map[string]string{},
+				TFVars: map[string]cty.Value{
+					"one":   cty.StringVal("andrew"),
+					"two":   cty.StringVal("bill"),
+					"three": cty.StringVal("carter"),
+				},
+			},
+			unknownTags: []string{},
+			params: map[string]assertParam{
+				"variable_values": ap().
+					def("andrew").optVals("andrew", "bill", "carter", "jason"),
+			},
+		},
 		{
 			name:        "unknownoption",
 			dir:         "unknownoption",

previewe2e_test.go

@@ -10,10 +10,12 @@ import (
 	"testing"
 	"time"
 
+	"github.com/hashicorp/terraform-exec/tfexec"
 	"github.com/stretchr/testify/require"
 
 	"github.com/coder/preview"
 	"github.com/coder/preview/internal/verify"
+	"github.com/coder/preview/tfvars"
 	"github.com/coder/preview/types"
 )
 
@@ -102,11 +104,11 @@ func Test_VerifyE2E(t *testing.T) {
 
 			entryWrkPath := t.TempDir()
 
-			for _, tfexec := range tfexecs {
-				tfexec := tfexec
+			for _, tfexecutable := range tfexecs {
+				tfexecutable := tfexecutable
 
-				t.Run(tfexec.Version, func(t *testing.T) {
-					wp := filepath.Join(entryWrkPath, tfexec.Version)
+				t.Run(tfexecutable.Version, func(t *testing.T) {
+					wp := filepath.Join(entryWrkPath, tfexecutable.Version)
 					err := os.MkdirAll(wp, 0755)
 					require.NoError(t, err, "creating working dir")
 
@@ -118,17 +120,27 @@ func Test_VerifyE2E(t *testing.T) {
 					err = verify.CopyTFFS(wp, subFS)
 					require.NoError(t, err, "copying test data to working dir")
 
-					exe, err := tfexec.WorkingDir(wp)
+					exe, err := tfexecutable.WorkingDir(wp)
 					require.NoError(t, err, "creating working executable")
 
 					ctx, cancel := context.WithTimeout(context.Background(), time.Minute*2)
 					defer cancel()
 					err = exe.Init(ctx)
 					require.NoError(t, err, "terraform init")
 
+					tfVarFiles, err := tfvars.TFVarFiles("", subFS)
+					require.NoError(t, err, "loading tfvars files")
+
+					planOpts := make([]tfexec.PlanOption, 0)
+					applyOpts := make([]tfexec.ApplyOption, 0)
+					for _, varFile := range tfVarFiles {
+						planOpts = append(planOpts, tfexec.VarFile(varFile))
+						applyOpts = append(applyOpts, tfexec.VarFile(varFile))
+					}
+
 					planOutFile := "tfplan"
 					planOutPath := filepath.Join(wp, planOutFile)
-					_, err = exe.Plan(ctx, planOutPath)
+					_, err = exe.Plan(ctx, planOutPath, planOpts...)
 					require.NoError(t, err, "terraform plan")
 
 					plan, err := exe.ShowPlan(ctx, planOutPath)
@@ -141,7 +153,7 @@ func Test_VerifyE2E(t *testing.T) {
 					err = os.WriteFile(filepath.Join(wp, "plan.json"), pd, 0644)
 					require.NoError(t, err, "writing plan.json")
 
-					_, err = exe.Apply(ctx)
+					_, err = exe.Apply(ctx, applyOpts...)
 					require.NoError(t, err, "terraform apply")
 
 					state, err := exe.Show(ctx)

testdata/tfvars/.auto.tfvars.json

@@ -0,0 +1 @@
+{"four":"jason"}

testdata/tfvars/main.tf

@@ -0,0 +1,61 @@
+// Base case for workspace tags + parameters.
+terraform {
+  required_providers {
+    coder = {
+      source = "coder/coder"
+    }
+    docker = {
+      source  = "kreuzwerker/docker"
+      version = "3.0.2"
+    }
+  }
+}
+
+variable "one" {
+  default = "alice"
+  type = string
+}
+
+variable "two" {
+  default = "bob"
+  type = string
+}
+
+variable "three" {
+  default = "charlie"
+  type = string
+}
+
+variable "four" {
+  default = "jack"
+  type = string
+}
+
+
+data "coder_parameter" "variable_values" {
+  name        = "variable_values"
+  description = "Just to show the variable values"
+  type        = "string"
+  default     = var.one
+
+
+  option {
+    name  = "one"
+    value = var.one
+  }
+
+  option {
+    name  = "two"
+    value = var.two
+  }
+
+  option {
+    name  = "three"
+    value = var.three
+  }
+
+  option {
+    name  = "four"
+    value = var.four
+  }
+}

testdata/tfvars/values.tfvars

@@ -0,0 +1,2 @@
+one="alex"
+three="claire"