targetgroup.go

/*
Copyright 2020 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package awstasks

import (
	"fmt"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/awserr"
	"github.com/aws/aws-sdk-go/service/elbv2"
	"k8s.io/klog/v2"
	"k8s.io/kops/upup/pkg/fi"
	"k8s.io/kops/upup/pkg/fi/cloudup/awsup"
	"k8s.io/kops/upup/pkg/fi/cloudup/cloudformation"
	"k8s.io/kops/upup/pkg/fi/cloudup/terraform"
	"k8s.io/kops/upup/pkg/fi/cloudup/terraformWriter"
)

// +kops:fitask
type TargetGroup struct {
	Name      *string
	Lifecycle fi.Lifecycle
	VPC       *VPC
	Tags      map[string]string
	Port      *int64
	Protocol  *string

	// ARN is the Amazon Resource Name for the Target Group
	ARN *string

	// Shared is set if this is an external LB (one we don't create or own)
	Shared *bool

	HealthyThreshold   *int64
	UnhealthyThreshold *int64
}

var _ fi.CompareWithID = &TargetGroup{}

func (e *TargetGroup) CompareWithID() *string {
	return e.ARN
}

func (e *TargetGroup) Find(c *fi.Context) (*TargetGroup, error) {
	cloud := c.Cloud.(awsup.AWSCloud)

	request := &elbv2.DescribeTargetGroupsInput{}
	if e.ARN != nil {
		request.TargetGroupArns = []*string{e.ARN}
	} else if e.Name != nil {
		request.Names = []*string{e.Name}
	}

	response, err := cloud.ELBV2().DescribeTargetGroups(request)
	if err != nil {
		if aerr, ok := err.(awserr.Error); ok && aerr.Code() == elbv2.ErrCodeTargetGroupNotFoundException {
			if !fi.BoolValue(e.Shared) {
				return nil, nil
			}
		}
		return nil, fmt.Errorf("error describing targetgroup %s: %v", *e.Name, err)
	}

	if len(response.TargetGroups) > 1 {
		return nil, fmt.Errorf("found %d TargetGroups with ID %q, expected 1", len(response.TargetGroups), fi.StringValue(e.Name))
	} else if len(response.TargetGroups) == 0 {
		return nil, nil
	}

	tg := response.TargetGroups[0]

	actual := &TargetGroup{
		Name:               tg.TargetGroupName,
		Port:               tg.Port,
		Protocol:           tg.Protocol,
		ARN:                tg.TargetGroupArn,
		HealthyThreshold:   tg.HealthyThresholdCount,
		UnhealthyThreshold: tg.UnhealthyThresholdCount,
		VPC:                &VPC{ID: tg.VpcId},
	}
	e.ARN = tg.TargetGroupArn

	tagsResp, err := cloud.ELBV2().DescribeTags(&elbv2.DescribeTagsInput{
		ResourceArns: []*string{tg.TargetGroupArn},
	})
	if err != nil {
		return nil, err
	}
	tags := make(map[string]string)
	for _, tagDesc := range tagsResp.TagDescriptions {
		for _, tag := range tagDesc.Tags {
			tags[fi.StringValue(tag.Key)] = fi.StringValue(tag.Value)
		}
	}
	actual.Tags = tags

	// Prevent spurious changes
	actual.Lifecycle = e.Lifecycle
	actual.Shared = e.Shared

	return actual, nil
}

func FindTargetGroupByName(cloud awsup.AWSCloud, findName string) (*elbv2.TargetGroup, error) {
	klog.V(2).Infof("Listing all TargetGroups for FindTargetGroupByName")

	request := &elbv2.DescribeTargetGroupsInput{
		Names: []*string{aws.String(findName)},
	}
	// ELB DescribeTags has a limit of 20 names, so we set the page size here to 20 also
	request.PageSize = aws.Int64(20)

	resp, err := cloud.ELBV2().DescribeTargetGroups(request)
	if err != nil {
		if aerr, ok := err.(awserr.Error); ok && aerr.Code() == elbv2.ErrCodeTargetGroupNotFoundException {
			return nil, nil
		}
		return nil, fmt.Errorf("error describing TargetGroups: %v", err)
	}
	if len(resp.TargetGroups) == 0 {
		return nil, nil
	}

	if len(resp.TargetGroups) != 1 {
		return nil, fmt.Errorf("Found multiple TargetGroups with Name %q", findName)
	}

	return resp.TargetGroups[0], nil
}

func (e *TargetGroup) Run(c *fi.Context) error {
	return fi.DefaultDeltaRunMethod(e, c)
}

func (_ *TargetGroup) ShouldCreate(a, e, changes *TargetGroup) (bool, error) {
	if fi.BoolValue(e.Shared) {
		return false, nil
	}
	return true, nil
}

func (s *TargetGroup) CheckChanges(a, e, changes *TargetGroup) error {
	return nil
}

func (_ *TargetGroup) RenderAWS(t *awsup.AWSAPITarget, a, e, changes *TargetGroup) error {
	shared := fi.BoolValue(e.Shared)
	if shared {
		return nil
	}

	// You register targets for your Network Load Balancer with a target group. By default, the load balancer sends requests
	// to registered targets using the port and protocol that you specified for the target group. You can override this port
	// when you register each target with the target group.

	if a == nil {
		request := &elbv2.CreateTargetGroupInput{
			Name:                    e.Name,
			Port:                    e.Port,
			Protocol:                e.Protocol,
			VpcId:                   e.VPC.ID,
			HealthyThresholdCount:   e.HealthyThreshold,
			UnhealthyThresholdCount: e.UnhealthyThreshold,
			Tags:                    awsup.ELBv2Tags(e.Tags),
		}

		klog.V(2).Infof("Creating Target Group for NLB")
		response, err := t.Cloud.ELBV2().CreateTargetGroup(request)
		if err != nil {
			return fmt.Errorf("Error creating target group for NLB : %v", err)
		}

		targetGroupArn := *response.TargetGroups[0].TargetGroupArn
		e.ARN = fi.String(targetGroupArn)
	} else {
		if a.ARN != nil {
			if err := t.AddELBV2Tags(fi.StringValue(a.ARN), e.Tags); err != nil {
				return err
			}
		}
	}
	return nil
}

// OrderTargetGroupsByName implements sort.Interface for []OrderTargetGroupsByName, based on port number
type OrderTargetGroupsByName []*TargetGroup

func (a OrderTargetGroupsByName) Len() int      { return len(a) }
func (a OrderTargetGroupsByName) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a OrderTargetGroupsByName) Less(i, j int) bool {
	return fi.StringValue(a[i].Name) < fi.StringValue(a[j].Name)
}

type terraformTargetGroup struct {
	Name        string                          `cty:"name"`
	Port        int64                           `cty:"port"`
	Protocol    string                          `cty:"protocol"`
	VPCID       terraformWriter.Literal         `cty:"vpc_id"`
	Tags        map[string]string               `cty:"tags"`
	HealthCheck terraformTargetGroupHealthCheck `cty:"health_check"`
}

type terraformTargetGroupHealthCheck struct {
	HealthyThreshold   int64  `cty:"healthy_threshold"`
	UnhealthyThreshold int64  `cty:"unhealthy_threshold"`
	Protocol           string `cty:"protocol"`
}

func (_ *TargetGroup) RenderTerraform(t *terraform.TerraformTarget, a, e, changes *TargetGroup) error {
	shared := fi.BoolValue(e.Shared)
	if shared {
		return nil
	}

	if e.VPC == nil {
		return fmt.Errorf("Missing VPC task from target group:\n%v\n%v", e, e.VPC)
	}

	tf := &terraformTargetGroup{
		Name:     *e.Name,
		Port:     *e.Port,
		Protocol: *e.Protocol,
		VPCID:    *e.VPC.TerraformLink(),
		Tags:     e.Tags,
		HealthCheck: terraformTargetGroupHealthCheck{
			HealthyThreshold:   *e.HealthyThreshold,
			UnhealthyThreshold: *e.UnhealthyThreshold,
			Protocol:           elbv2.ProtocolEnumTcp,
		},
	}

	return t.RenderResource("aws_lb_target_group", *e.Name, tf)
}

func (e *TargetGroup) TerraformLink(params ...string) *terraformWriter.Literal {
	shared := fi.BoolValue(e.Shared)
	if shared {
		if e.ARN != nil {
			return terraformWriter.LiteralFromStringValue(*e.ARN)
		} else {
			klog.Warningf("ID not set on shared Target Group %v", e)
		}
	}
	return terraformWriter.LiteralProperty("aws_lb_target_group", *e.Name, "id")
}

type cloudformationTargetGroup struct {
	Name     string                  `json:"Name"`
	Port     int64                   `json:"Port"`
	Protocol string                  `json:"Protocol"`
	VPCID    *cloudformation.Literal `json:"VpcId"`
	Tags     []cloudformationTag     `json:"Tags"`

	HealthCheckProtocol string `json:"HealthCheckProtocol"`
	HealthyThreshold    int64  `json:"HealthyThresholdCount"`
	UnhealthyThreshold  int64  `json:"UnhealthyThresholdCount"`
}

func (_ *TargetGroup) RenderCloudformation(t *cloudformation.CloudformationTarget, a, e, changes *TargetGroup) error {
	shared := fi.BoolValue(e.Shared)
	if shared {
		return nil
	}

	cf := &cloudformationTargetGroup{
		Name:                *e.Name,
		Port:                *e.Port,
		Protocol:            *e.Protocol,
		VPCID:               e.VPC.CloudformationLink(),
		Tags:                buildCloudformationTags(e.Tags),
		HealthCheckProtocol: *e.Protocol,
		HealthyThreshold:    *e.HealthyThreshold,
		UnhealthyThreshold:  *e.UnhealthyThreshold,
	}
	return t.RenderResource("AWS::ElasticLoadBalancingV2::TargetGroup", *e.Name, cf)
}

func (e *TargetGroup) CloudformationLink() *cloudformation.Literal {
	shared := fi.BoolValue(e.Shared)
	if shared {
		if e.ARN != nil {
			return cloudformation.LiteralString(*e.ARN)
		} else {
			klog.Warningf("ID not set on shared Target Group: %v", e)
		}
	}

	return cloudformation.Ref("AWS::ElasticLoadBalancingV2::TargetGroup", *e.Name)
}