Add configuration for controlling the autonaming behavior

examples/autonaming-overlay/index.ts

@@ -1,6 +1,9 @@
+import * as pulumi from '@pulumi/pulumi';
 import * as aws from "@pulumi/aws-native";
 
-new aws.iam.Role("myRole".repeat(11), {
+const config = new pulumi.Config();
+const name = config.require('roleName');
+const role = new aws.iam.Role(name, {
   assumeRolePolicyDocument: {
     Version: "2012-10-17",
     Statement: [
@@ -14,3 +17,5 @@ new aws.iam.Role("myRole".repeat(11), {
     ],
   },
 });
+
+export const roleName = role.roleName;

examples/examples_nodejs_test.go

@@ -148,6 +148,9 @@ func TestAutoNamingOverlay(t *testing.T) {
 		With(integration.ProgramTestOptions{
 			Dir:           filepath.Join(getCwd(t), "autonaming-overlay"),
 			Stderr:        &buf,
+			Config: map[string]string{
+				"roleName":              "myReallyLongRoleNameThatIsLongerThan64CharactersOneTwoThreeFour",
+			},
 			ExpectFailure: true,
 			ExtraRuntimeValidation: func(t *testing.T, stackInfo integration.RuntimeValidationStackInfo) {
 				assert.Contains(t, buf.String(), "is too large to fix max length constraint of 64")
@@ -157,6 +160,24 @@ func TestAutoNamingOverlay(t *testing.T) {
 	integration.ProgramTest(t, &test)
 }
 
+func TestAutoNamingOverlayWithConfig(t *testing.T) {
+	test := getJSBaseOptions(t).
+		With(integration.ProgramTestOptions{
+			Dir: filepath.Join(getCwd(t), "autonaming-overlay"),
+			Config: map[string]string{
+				"aws-native:autoNaming": `{"autoTrim": true, "randomSuffixMinLength": 7}`,
+				"roleName":              "myReallyLongRoleNameThatIsLongerThan64CharactersOneTwoThreeFour",
+			},
+			ExtraRuntimeValidation: func(t *testing.T, stackInfo integration.RuntimeValidationStackInfo) {
+				roleName := stackInfo.Outputs["roleName"].(string)
+				assert.Equal(t, 64, len(roleName))
+				assert.Regexp(t, "myReallyLongRoleNameThatIsLon64CharactersOneTwoThreeFour-[a-z0-9]{7}", roleName)
+			},
+		})
+
+	integration.ProgramTest(t, &test)
+}
+
 func TestParallelTs(t *testing.T) {
 	test := getJSBaseOptions(t).
 		With(integration.ProgramTestOptions{

provider/cmd/pulumi-resource-aws-native/schema.json

@@ -281,6 +281,10 @@
                 "$ref": "#/types/aws-native:config:AssumeRole",
                 "description": "Configuration for retrieving temporary credentials from the STS service."
             },
+            "autoNaming": {
+                "$ref": "#/types/aws-native:config:AutoNaming",
+                "description": "The configuration for automatically naming resources."
+            },
             "defaultTags": {
                 "$ref": "#/types/aws-native:config:DefaultTags",
                 "description": "Configuration block with resource tag settings to apply across all resources handled by this provider. This is designed to replace redundant per-resource `tags` configurations. Provider tags can be overridden with new values, but not excluded from specific resources. To override provider tag values, use the `tags` argument within a resource to configure new tag values for matching keys."
@@ -28410,6 +28414,31 @@
             },
             "type": "object"
         },
+        "aws-native:config:AutoNaming": {
+            "description": "The configuration for automatically naming resources.",
+            "properties": {
+                "autoTrim": {
+                    "type": "boolean",
+                    "description": "Automatically trim the auto-generated name to meet the maximum length constraint.",
+                    "language": {
+                        "python": {
+                            "mapCase": false
+                        }
+                    }
+                },
+                "randomSuffixMinLength": {
+                    "type": "integer",
+                    "description": "The minimum length of the random suffix to append to the auto-generated name.",
+                    "default": 1,
+                    "language": {
+                        "python": {
+                            "mapCase": false
+                        }
+                    }
+                }
+            },
+            "type": "object"
+        },
         "aws-native:config:DefaultTags": {
             "description": "The configuration with resource tag settings to apply across all resources handled by this provider. This is designed to replace redundant per-resource `tags` configurations. Provider tags can be overridden with new values, but not excluded from specific resources. To override provider tag values, use the `tags` argument within a resource to configure new tag values for matching keys.",
             "properties": {
@@ -61409,6 +61438,31 @@
             },
             "type": "object"
         },
+        "aws-native:index:ProviderAutoNaming": {
+            "description": "The configuration for automatically naming resources.",
+            "properties": {
+                "autoTrim": {
+                    "type": "boolean",
+                    "description": "Automatically trim the auto-generated name to meet the maximum length constraint.",
+                    "language": {
+                        "python": {
+                            "mapCase": false
+                        }
+                    }
+                },
+                "randomSuffixMinLength": {
+                    "type": "integer",
+                    "description": "The minimum length of the random suffix to append to the auto-generated name.",
+                    "default": 1,
+                    "language": {
+                        "python": {
+                            "mapCase": false
+                        }
+                    }
+                }
+            },
+            "type": "object"
+        },
         "aws-native:index:ProviderDefaultTags": {
             "description": "The configuration with resource tag settings to apply across all resources handled by this provider. This is designed to replace redundant per-resource `tags` configurations. Provider tags can be overridden with new values, but not excluded from specific resources. To override provider tag values, use the `tags` argument within a resource to configure new tag values for matching keys.",
             "properties": {
@@ -168697,6 +168751,10 @@
                 "$ref": "#/types/aws-native:index:ProviderAssumeRole",
                 "description": "Configuration for retrieving temporary credentials from the STS service."
             },
+            "autoNaming": {
+                "$ref": "#/types/aws-native:index:ProviderAutoNaming",
+                "description": "The configuration for automatically naming resources."
+            },
             "defaultTags": {
                 "$ref": "#/types/aws-native:index:ProviderDefaultTags",
                 "description": "Configuration block with resource tag settings to apply across all resources handled by this provider. This is designed to replace redundant per-resource `tags` configurations. Provider tags can be overridden with new values, but not excluded from specific resources. To override provider tag values, use the `tags` argument within a resource to configure new tag values for matching keys."
@@ -168786,6 +168844,10 @@
                 "$ref": "#/types/aws-native:index:ProviderAssumeRole",
                 "description": "Configuration for retrieving temporary credentials from the STS service."
             },
+            "autoNaming": {
+                "$ref": "#/types/aws-native:index:ProviderAutoNaming",
+                "description": "The configuration for automatically naming resources."
+            },
             "defaultTags": {
                 "$ref": "#/types/aws-native:index:ProviderDefaultTags",
                 "description": "Configuration block with resource tag settings to apply across all resources handled by this provider. This is designed to replace redundant per-resource `tags` configurations. Provider tags can be overridden with new values, but not excluded from specific resources. To override provider tag values, use the `tags` argument within a resource to configure new tag values for matching keys."

provider/pkg/autonaming/application.go

@@ -4,23 +4,30 @@ package autonaming
 
 import (
 	"fmt"
+	"math"
 
 	"github.com/pulumi/pulumi-aws-native/provider/pkg/metadata"
 	"github.com/pulumi/pulumi/sdk/v3/go/common/resource"
 )
 
+type AutoNamingConfig struct {
+	AutoTrim              bool `json:"autoTrim"`
+	RandomSuffixMinLength int  `json:"randomSuffixMinLength"`
+}
+
 func ApplyAutoNaming(
 	spec *metadata.AutoNamingSpec,
 	urn resource.URN,
 	randomSeed []byte,
 	olds,
 	news resource.PropertyMap,
+	config *AutoNamingConfig,
 ) error {
 	if spec == nil {
 		return nil
 	}
 	// Auto-name fields if not already specified
-	val, err := getDefaultName(randomSeed, urn, spec, olds, news)
+	val, err := getDefaultName(randomSeed, urn, spec, olds, news, config)
 	if err != nil {
 		return err
 	}
@@ -39,6 +46,7 @@ func getDefaultName(
 	autoNamingSpec *metadata.AutoNamingSpec,
 	olds,
 	news resource.PropertyMap,
+	config *AutoNamingConfig,
 ) (resource.PropertyValue, error) {
 	sdkName := autoNamingSpec.SdkName
 
@@ -58,10 +66,23 @@ func getDefaultName(
 		return resource.PropertyValue{}, err
 	}
 
+	var autoTrim bool
+	// resource.NewUniqueName does not allow for a random suffix shorter than 1.
+	randomSuffixMinLength := 1
+	if config != nil {
+		autoTrim = config.AutoTrim
+		if config.RandomSuffixMinLength != 0 {
+			randomSuffixMinLength = config.RandomSuffixMinLength
+		}
+	}
+
 	// Generate random name that fits the length constraints.
 	name := urn.Name()
 	prefix := name + "-"
-	randLength := 7
+	randLength := 7 // Default value
+	if randomSuffixMinLength > randLength {
+		randLength = randomSuffixMinLength
+	}
 	if len(prefix)+namingTrivia.Length()+randLength < autoNamingSpec.MinLength {
 		randLength = autoNamingSpec.MinLength - len(prefix) - namingTrivia.Length()
 	}
@@ -70,6 +91,19 @@ func getDefaultName(
 	if autoNamingSpec.MaxLength > 0 {
 		left := autoNamingSpec.MaxLength - len(prefix) - namingTrivia.Length()
 
+		if left <= 0 && autoTrim {
+			autoTrimMaxLength := autoNamingSpec.MaxLength - namingTrivia.Length() - randomSuffixMinLength
+			if autoTrimMaxLength <= 0 {
+				return resource.PropertyValue{}, fmt.Errorf("failed to auto-generate value for %[1]q."+
+					" Prefix: %[2]q is too large to fix max length constraint of %[3]d"+
+					" with required suffix length %[4]d. Please provide a value for %[1]q",
+					sdkName, prefix, autoNamingSpec.MaxLength, randomSuffixMinLength)
+			}
+			prefix = trimName(prefix, autoTrimMaxLength)
+			randLength = randomSuffixMinLength
+			left = randomSuffixMinLength
+		}
+
 		if left <= 0 {
 			if namingTrivia.Length() > 0 {
 				return resource.PropertyValue{}, fmt.Errorf("failed to auto-generate value for %[1]q."+
@@ -101,3 +135,25 @@ func getDefaultName(
 
 	return resource.NewStringProperty(random), nil
 }
+
+// trimName will trim the prefix to fit within the max length constraint.
+// It will cut out part of the middle, keeping the beginning and the end of the string.
+// This is so that really long generated names can still be unique. For example, if the
+// user creates a resource name by appending the parent onto the child, you could end up
+// with names like:
+// - "topParent-middleParent-bottonParent-child1"
+// - "topParent-middleParent-bottonParent-child2"
+//
+// If the max length is 30, the trimmed generated name for both would be something like
+// "topParent-middleParent-bottonP" and you would not be able to tell them apart.
+//
+// By trimming from the middle you would end up with something like this, preserving
+// the uniqueness of the generated names:
+// - "topParent-middlonParent-child1"
+// - "topParent-middlonParent-child2"
+func trimName(name string, maxLength int) string {
+	floorHalf := math.Floor(float64(maxLength) / 2)
+	half := int(floorHalf)
+	left := maxLength - half
+	return name[0:half] + name[len(name)-left:]
+}