Allow to fail on specific warning messages

modules/terraform/apply_test.go

@@ -2,6 +2,7 @@ package terraform
 
 import (
 	"path/filepath"
+	"strings"
 	"testing"
 	"time"
 
@@ -63,6 +64,73 @@ func TestApplyWithErrorWithRetry(t *testing.T) {
 
 	require.Contains(t, out, "This is the first run, exiting with an error")
 }
+
+func TestApplyWithWarning(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		folder   string
+		isError  bool
+		warnings map[string]string
+	}{
+		{
+			name:    "Warning",
+			folder:  "../../test/fixtures/terraform-with-warning",
+			isError: true,
+			warnings: map[string]string{
+				"lorem ipsum": "lorem ipsum warning",
+			},
+		},
+		{
+			name:    "WarningNotMatch",
+			folder:  "../../test/fixtures/terraform-with-warning",
+			isError: false,
+			warnings: map[string]string{
+				"lorem ipsum dolor sit amet": "some warning",
+			},
+		},
+		{
+			name:    "Error",
+			folder:  "../../test/fixtures/terraform-with-error",
+			isError: true,
+			warnings: map[string]string{
+				"lorem ipsum": "lorem ipsum warning",
+			},
+		},
+		{
+			name:    "NoError",
+			folder:  "../../test/fixtures/terraform-no-error",
+			isError: false,
+			warnings: map[string]string{
+				"lorem ipsum": "lorem ipsum warning",
+			},
+		},
+	}
+
+	for _, scenario := range scenarios {
+		scenario := scenario
+		t.Run(scenario.name, func(t *testing.T) {
+			t.Parallel()
+
+			testFolder, err := files.CopyTerraformFolderToTemp(scenario.folder, strings.Replace(t.Name(), "/", "-", -1))
+			require.NoError(t, err)
+
+			options := WithDefaultRetryableErrors(t, &Options{
+				TerraformDir:     testFolder,
+				NoColor:          true,
+				WarningsAsErrors: scenario.warnings,
+			})
+
+			out, err := InitAndApplyE(t, options)
+			if scenario.isError {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+			}
+			assert.NotEmpty(t, out)
+		})
+	}
+}
+
 func TestTgApplyAllTgError(t *testing.T) {
 	t.Parallel()
 

modules/terraform/cmd.go

@@ -3,6 +3,8 @@ package terraform
 import (
 	"fmt"
 	"os/exec"
+	"regexp"
+	"strings"
 
 	"github.com/gruntwork-io/terratest/modules/collections"
 	"github.com/gruntwork-io/terratest/modules/retry"
@@ -81,9 +83,18 @@ func RunTerraformCommandE(t testing.TestingT, additionalOptions *Options, additi
 
 	cmd := generateCommand(options, args...)
 	description := fmt.Sprintf("%s %v", options.TerraformBinary, args)
+
 	return retry.DoWithRetryableErrorsE(t, description, options.RetryableTerraformErrors, options.MaxRetries, options.TimeBetweenRetries, func() (string, error) {
-		return shell.RunCommandAndGetOutputE(t, cmd)
+		s, err := shell.RunCommandAndGetOutputE(t, cmd)
+		if err != nil {
+			return s, err
+		}
+		if err := hasWarning(additionalOptions, s); err != nil {
+			return s, err
+		}
+		return s, err
 	})
+
 }
 
 // RunTerraformCommandAndGetStdoutE runs terraform with the given arguments and options and returns solely its stdout
@@ -94,7 +105,14 @@ func RunTerraformCommandAndGetStdoutE(t testing.TestingT, additionalOptions *Opt
 	cmd := generateCommand(options, args...)
 	description := fmt.Sprintf("%s %v", options.TerraformBinary, args)
 	return retry.DoWithRetryableErrorsE(t, description, options.RetryableTerraformErrors, options.MaxRetries, options.TimeBetweenRetries, func() (string, error) {
-		return shell.RunCommandAndGetStdOutE(t, cmd)
+		s, err := shell.RunCommandAndGetOutputE(t, cmd)
+		if err != nil {
+			return s, err
+		}
+		if err := hasWarning(additionalOptions, s); err != nil {
+			return s, err
+		}
+		return s, err
 	})
 }
 
@@ -137,3 +155,19 @@ func defaultTerraformExecutable() string {
 	// fallback to Tofu if terraform is not available
 	return TofuDefaultPath
 }
+
+func hasWarning(opts *Options, out string) error {
+	for k, v := range opts.WarningsAsErrors {
+		str := fmt.Sprintf("\nWarning: %s[^\n]*\n", k)
+		re, err := regexp.Compile(str)
+		if err != nil {
+			return fmt.Errorf("cannot compile regex for warning detection: %w", err)
+		}
+		m := re.FindAllString(out, -1)
+		if len(m) == 0 {
+			continue
+		}
+		return fmt.Errorf("warning(s) were found: %s:\n%s", v, strings.Join(m, ""))
+	}
+	return nil
+}

modules/terraform/options.go

@@ -71,6 +71,7 @@ type Options struct {
 	PlanFilePath             string                 // The path to output a plan file to (for the plan command) or read one from (for the apply command)
 	PluginDir                string                 // The path of downloaded plugins to pass to the terraform init command (-plugin-dir)
 	SetVarsAfterVarFiles     bool                   // Pass -var options after -var-file options to Terraform commands
+	WarningsAsErrors         map[string]string      // Terraform warning messages that should be treated as errors. The keys are a regexp to match against the warning and the value is what to display to a user if that warning is matched.
 }
 
 // Clone makes a deep copy of most fields on the Options object and returns it.
@@ -99,6 +100,10 @@ func (options *Options) Clone() (*Options, error) {
 	for key, val := range options.RetryableTerraformErrors {
 		newOptions.RetryableTerraformErrors[key] = val
 	}
+	newOptions.WarningsAsErrors = make(map[string]string)
+	for key, val := range options.WarningsAsErrors {
+		newOptions.WarningsAsErrors[key] = val
+	}
 
 	return newOptions, nil
 }

test/fixtures/terraform-with-warning/main.tf

@@ -0,0 +1,22 @@
+terraform {
+  required_providers {
+    validation = {
+      source  = "tlkamp/validation"
+      version = "1.1.1"
+    }
+    null = {
+      source  = "hashicorp/null"
+      version = "3.2.2"
+    }
+  }
+}
+
+# this data source will produce warning when `condition` is evaluated to `true`
+data "validation_warning" "warn" {
+  for_each  = toset([for i in range(10) : format("%02d", i)])
+  condition = true
+  summary   = "lorem ipsum ${each.value}"
+  details   = "lorem ipsum dolor sit amet"
+}
+
+resource "null_resource" "empty" {}