service/applicationautoscaling/api_op_DescribeScalingPolicies.go

// Code generated by smithy-go-codegen DO NOT EDIT.

package applicationautoscaling

import (
	"context"
	"fmt"
	awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
	"github.com/aws/aws-sdk-go-v2/aws/signer/v4"
	"github.com/aws/aws-sdk-go-v2/service/applicationautoscaling/types"
	"github.com/aws/smithy-go/middleware"
	smithyhttp "github.com/aws/smithy-go/transport/http"
)

// Describes the Application Auto Scaling scaling policies for the specified
// service namespace. You can filter the results using ResourceId,
// ScalableDimension, and PolicyNames. For more information, see Target tracking
// scaling policies
// (https://docs.aws.amazon.com/autoscaling/application/userguide/application-auto-scaling-target-tracking.html)
// and Step scaling policies
// (https://docs.aws.amazon.com/autoscaling/application/userguide/application-auto-scaling-step-scaling-policies.html)
// in the Application Auto Scaling User Guide.
func (c *Client) DescribeScalingPolicies(ctx context.Context, params *DescribeScalingPoliciesInput, optFns ...func(*Options)) (*DescribeScalingPoliciesOutput, error) {
	if params == nil {
		params = &DescribeScalingPoliciesInput{}
	}

	result, metadata, err := c.invokeOperation(ctx, "DescribeScalingPolicies", params, optFns, addOperationDescribeScalingPoliciesMiddlewares)
	if err != nil {
		return nil, err
	}

	out := result.(*DescribeScalingPoliciesOutput)
	out.ResultMetadata = metadata
	return out, nil
}

type DescribeScalingPoliciesInput struct {

	// The namespace of the AWS service that provides the resource. For a resource
	// provided by your own application or service, use custom-resource instead.
	//
	// This member is required.
	ServiceNamespace types.ServiceNamespace

	// The maximum number of scalable targets. This value can be between 1 and 50. The
	// default value is 50. If this parameter is used, the operation returns up to
	// MaxResults results at a time, along with a NextToken value. To get the next set
	// of results, include the NextToken value in a subsequent call. If this parameter
	// is not used, the operation returns up to 50 results and a NextToken value, if
	// applicable.
	MaxResults *int32

	// The token for the next set of results.
	NextToken *string

	// The names of the scaling policies to describe.
	PolicyNames []string

	// The identifier of the resource associated with the scaling policy. This string
	// consists of the resource type and unique identifier.
	//
	// * ECS service - The
	// resource type is service and the unique identifier is the cluster name and
	// service name. Example: service/default/sample-webapp.
	//
	// * Spot Fleet request -
	// The resource type is spot-fleet-request and the unique identifier is the Spot
	// Fleet request ID. Example:
	// spot-fleet-request/sfr-73fbd2ce-aa30-494c-8788-1cee4EXAMPLE.
	//
	// * EMR cluster -
	// The resource type is instancegroup and the unique identifier is the cluster ID
	// and instance group ID. Example:
	// instancegroup/j-2EEZNYKUA1NTV/ig-1791Y4E1L8YI0.
	//
	// * AppStream 2.0 fleet - The
	// resource type is fleet and the unique identifier is the fleet name. Example:
	// fleet/sample-fleet.
	//
	// * DynamoDB table - The resource type is table and the
	// unique identifier is the table name. Example: table/my-table.
	//
	// * DynamoDB global
	// secondary index - The resource type is index and the unique identifier is the
	// index name. Example: table/my-table/index/my-table-index.
	//
	// * Aurora DB cluster -
	// The resource type is cluster and the unique identifier is the cluster name.
	// Example: cluster:my-db-cluster.
	//
	// * Amazon SageMaker endpoint variant - The
	// resource type is variant and the unique identifier is the resource ID. Example:
	// endpoint/my-end-point/variant/KMeansClustering.
	//
	// * Custom resources are not
	// supported with a resource type. This parameter must specify the OutputValue from
	// the CloudFormation template stack used to access the resources. The unique
	// identifier is defined by the service provider. More information is available in
	// our GitHub repository
	// (https://github.com/aws/aws-auto-scaling-custom-resource).
	//
	// * Amazon Comprehend
	// document classification endpoint - The resource type and unique identifier are
	// specified using the endpoint ARN. Example:
	// arn:aws:comprehend:us-west-2:123456789012:document-classifier-endpoint/EXAMPLE.
	//
	// *
	// Amazon Comprehend entity recognizer endpoint - The resource type and unique
	// identifier are specified using the endpoint ARN. Example:
	// arn:aws:comprehend:us-west-2:123456789012:entity-recognizer-endpoint/EXAMPLE.
	//
	// *
	// Lambda provisioned concurrency - The resource type is function and the unique
	// identifier is the function name with a function version or alias name suffix
	// that is not $LATEST. Example: function:my-function:prod or
	// function:my-function:1.
	//
	// * Amazon Keyspaces table - The resource type is table
	// and the unique identifier is the table name. Example:
	// keyspace/mykeyspace/table/mytable.
	//
	// * Amazon MSK cluster - The resource type and
	// unique identifier are specified using the cluster ARN. Example:
	// arn:aws:kafka:us-east-1:123456789012:cluster/demo-cluster-1/6357e0b2-0e6a-4b86-a0b4-70df934c2e31-5.
	ResourceId *string

	// The scalable dimension. This string consists of the service namespace, resource
	// type, and scaling property. If you specify a scalable dimension, you must also
	// specify a resource ID.
	//
	// * ecs:service:DesiredCount - The desired task count of
	// an ECS service.
	//
	// * ec2:spot-fleet-request:TargetCapacity - The target capacity
	// of a Spot Fleet request.
	//
	// * elasticmapreduce:instancegroup:InstanceCount - The
	// instance count of an EMR Instance Group.
	//
	// * appstream:fleet:DesiredCapacity -
	// The desired capacity of an AppStream 2.0 fleet.
	//
	// *
	// dynamodb:table:ReadCapacityUnits - The provisioned read capacity for a DynamoDB
	// table.
	//
	// * dynamodb:table:WriteCapacityUnits - The provisioned write capacity for
	// a DynamoDB table.
	//
	// * dynamodb:index:ReadCapacityUnits - The provisioned read
	// capacity for a DynamoDB global secondary index.
	//
	// *
	// dynamodb:index:WriteCapacityUnits - The provisioned write capacity for a
	// DynamoDB global secondary index.
	//
	// * rds:cluster:ReadReplicaCount - The count of
	// Aurora Replicas in an Aurora DB cluster. Available for Aurora MySQL-compatible
	// edition and Aurora PostgreSQL-compatible edition.
	//
	// *
	// sagemaker:variant:DesiredInstanceCount - The number of EC2 instances for an
	// Amazon SageMaker model endpoint variant.
	//
	// *
	// custom-resource:ResourceType:Property - The scalable dimension for a custom
	// resource provided by your own application or service.
	//
	// *
	// comprehend:document-classifier-endpoint:DesiredInferenceUnits - The number of
	// inference units for an Amazon Comprehend document classification endpoint.
	//
	// *
	// comprehend:entity-recognizer-endpoint:DesiredInferenceUnits - The number of
	// inference units for an Amazon Comprehend entity recognizer endpoint.
	//
	// *
	// lambda:function:ProvisionedConcurrency - The provisioned concurrency for a
	// Lambda function.
	//
	// * cassandra:table:ReadCapacityUnits - The provisioned read
	// capacity for an Amazon Keyspaces table.
	//
	// * cassandra:table:WriteCapacityUnits -
	// The provisioned write capacity for an Amazon Keyspaces table.
	//
	// *
	// kafka:broker-storage:VolumeSize - The provisioned volume size (in GiB) for
	// brokers in an Amazon MSK cluster.
	ScalableDimension types.ScalableDimension
}

type DescribeScalingPoliciesOutput struct {

	// The token required to get the next set of results. This value is null if there
	// are no more results to return.
	NextToken *string

	// Information about the scaling policies.
	ScalingPolicies []types.ScalingPolicy

	// Metadata pertaining to the operation's result.
	ResultMetadata middleware.Metadata
}

func addOperationDescribeScalingPoliciesMiddlewares(stack *middleware.Stack, options Options) (err error) {
	err = stack.Serialize.Add(&awsAwsjson11_serializeOpDescribeScalingPolicies{}, middleware.After)
	if err != nil {
		return err
	}
	err = stack.Deserialize.Add(&awsAwsjson11_deserializeOpDescribeScalingPolicies{}, middleware.After)
	if err != nil {
		return err
	}
	if err = addSetLoggerMiddleware(stack, options); err != nil {
		return err
	}
	if err = awsmiddleware.AddClientRequestIDMiddleware(stack); err != nil {
		return err
	}
	if err = smithyhttp.AddComputeContentLengthMiddleware(stack); err != nil {
		return err
	}
	if err = addResolveEndpointMiddleware(stack, options); err != nil {
		return err
	}
	if err = v4.AddComputePayloadSHA256Middleware(stack); err != nil {
		return err
	}
	if err = addRetryMiddlewares(stack, options); err != nil {
		return err
	}
	if err = addHTTPSignerV4Middleware(stack, options); err != nil {
		return err
	}
	if err = awsmiddleware.AddRawResponseToMetadata(stack); err != nil {
		return err
	}
	if err = awsmiddleware.AddRecordResponseTiming(stack); err != nil {
		return err
	}
	if err = addClientUserAgent(stack); err != nil {
		return err
	}
	if err = smithyhttp.AddErrorCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = smithyhttp.AddCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = addOpDescribeScalingPoliciesValidationMiddleware(stack); err != nil {
		return err
	}
	if err = stack.Initialize.Add(newServiceMetadataMiddleware_opDescribeScalingPolicies(options.Region), middleware.Before); err != nil {
		return err
	}
	if err = addRequestIDRetrieverMiddleware(stack); err != nil {
		return err
	}
	if err = addResponseErrorMiddleware(stack); err != nil {
		return err
	}
	if err = addRequestResponseLogging(stack, options); err != nil {
		return err
	}
	return nil
}

// DescribeScalingPoliciesAPIClient is a client that implements the
// DescribeScalingPolicies operation.
type DescribeScalingPoliciesAPIClient interface {
	DescribeScalingPolicies(context.Context, *DescribeScalingPoliciesInput, ...func(*Options)) (*DescribeScalingPoliciesOutput, error)
}

var _ DescribeScalingPoliciesAPIClient = (*Client)(nil)

// DescribeScalingPoliciesPaginatorOptions is the paginator options for
// DescribeScalingPolicies
type DescribeScalingPoliciesPaginatorOptions struct {
	// The maximum number of scalable targets. This value can be between 1 and 50. The
	// default value is 50. If this parameter is used, the operation returns up to
	// MaxResults results at a time, along with a NextToken value. To get the next set
	// of results, include the NextToken value in a subsequent call. If this parameter
	// is not used, the operation returns up to 50 results and a NextToken value, if
	// applicable.
	Limit int32

	// Set to true if pagination should stop if the service returns a pagination token
	// that matches the most recent token provided to the service.
	StopOnDuplicateToken bool
}

// DescribeScalingPoliciesPaginator is a paginator for DescribeScalingPolicies
type DescribeScalingPoliciesPaginator struct {
	options   DescribeScalingPoliciesPaginatorOptions
	client    DescribeScalingPoliciesAPIClient
	params    *DescribeScalingPoliciesInput
	nextToken *string
	firstPage bool
}

// NewDescribeScalingPoliciesPaginator returns a new
// DescribeScalingPoliciesPaginator
func NewDescribeScalingPoliciesPaginator(client DescribeScalingPoliciesAPIClient, params *DescribeScalingPoliciesInput, optFns ...func(*DescribeScalingPoliciesPaginatorOptions)) *DescribeScalingPoliciesPaginator {
	if params == nil {
		params = &DescribeScalingPoliciesInput{}
	}

	options := DescribeScalingPoliciesPaginatorOptions{}
	if params.MaxResults != nil {
		options.Limit = *params.MaxResults
	}

	for _, fn := range optFns {
		fn(&options)
	}

	return &DescribeScalingPoliciesPaginator{
		options:   options,
		client:    client,
		params:    params,
		firstPage: true,
	}
}

// HasMorePages returns a boolean indicating whether more pages are available
func (p *DescribeScalingPoliciesPaginator) HasMorePages() bool {
	return p.firstPage || p.nextToken != nil
}

// NextPage retrieves the next DescribeScalingPolicies page.
func (p *DescribeScalingPoliciesPaginator) NextPage(ctx context.Context, optFns ...func(*Options)) (*DescribeScalingPoliciesOutput, error) {
	if !p.HasMorePages() {
		return nil, fmt.Errorf("no more pages available")
	}

	params := *p.params
	params.NextToken = p.nextToken

	var limit *int32
	if p.options.Limit > 0 {
		limit = &p.options.Limit
	}
	params.MaxResults = limit

	result, err := p.client.DescribeScalingPolicies(ctx, &params, optFns...)
	if err != nil {
		return nil, err
	}
	p.firstPage = false

	prevToken := p.nextToken
	p.nextToken = result.NextToken

	if p.options.StopOnDuplicateToken && prevToken != nil && p.nextToken != nil && *prevToken == *p.nextToken {
		p.nextToken = nil
	}

	return result, nil
}

func newServiceMetadataMiddleware_opDescribeScalingPolicies(region string) *awsmiddleware.RegisterServiceMetadata {
	return &awsmiddleware.RegisterServiceMetadata{
		Region:        region,
		ServiceID:     ServiceID,
		SigningName:   "application-autoscaling",
		OperationName: "DescribeScalingPolicies",
	}
}