instance.go

package awstasks

import (
	"fmt"

	"encoding/base64"
	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/service/ec2"
	"github.com/golang/glog"
	"k8s.io/kops/upup/pkg/fi"
	"k8s.io/kops/upup/pkg/fi/cloudup/awsup"
	"k8s.io/kops/upup/pkg/fi/cloudup/terraform"
	"strings"
)

const MaxUserDataSize = 16384

type Instance struct {
	ID *string

	UserData fi.Resource

	Subnet           *Subnet
	PrivateIPAddress *string

	Name *string
	Tags map[string]string

	ImageID            *string
	InstanceType       *string
	SSHKey             *SSHKey
	SecurityGroups     []*SecurityGroup
	AssociatePublicIP  *bool
	IAMInstanceProfile *IAMInstanceProfile
}

var _ fi.CompareWithID = &Instance{}

func (s *Instance) CompareWithID() *string {
	return s.ID
}

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

	filters := cloud.BuildFilters(e.Name)
	filters = append(filters, awsup.NewEC2Filter("instance-state-name", "pending", "running", "stopping", "stopped"))
	request := &ec2.DescribeInstancesInput{
		Filters: filters,
	}

	response, err := cloud.EC2().DescribeInstances(request)
	if err != nil {
		return nil, fmt.Errorf("error listing instances: %v", err)
	}

	instances := []*ec2.Instance{}
	if response != nil {
		for _, reservation := range response.Reservations {
			for _, instance := range reservation.Instances {
				instances = append(instances, instance)
			}
		}
	}

	if len(instances) == 0 {
		return nil, nil
	}

	if len(instances) != 1 {
		return nil, fmt.Errorf("found multiple Instances with name: %s", *e.Name)
	}

	glog.V(2).Info("found existing instance")
	i := instances[0]

	if i.InstanceId == nil {
		return nil, fmt.Errorf("found instance, but InstanceId was nil")
	}

	actual := &Instance{
		ID:               i.InstanceId,
		PrivateIPAddress: i.PrivateIpAddress,
		InstanceType:     i.InstanceType,
		ImageID:          i.ImageId,
		Name:             findNameTag(i.Tags),
	}

	// Fetch instance UserData
	{
		request := &ec2.DescribeInstanceAttributeInput{}
		request.InstanceId = i.InstanceId
		request.Attribute = aws.String("userData")
		response, err := cloud.EC2().DescribeInstanceAttribute(request)
		if err != nil {
			return nil, fmt.Errorf("error querying EC2 for user metadata for instance %q: %v", *i.InstanceId, err)
		}
		if response.UserData != nil {
			b, err := base64.StdEncoding.DecodeString(aws.StringValue(response.UserData.Value))
			if err != nil {
				return nil, fmt.Errorf("error decoding EC2 UserData: %v", err)
			}
			actual.UserData = fi.NewBytesResource(b)
		}
	}

	if i.SubnetId != nil {
		actual.Subnet = &Subnet{ID: i.SubnetId}
	}
	if i.KeyName != nil {
		actual.SSHKey = &SSHKey{Name: i.KeyName}
	}

	for _, sg := range i.SecurityGroups {
		actual.SecurityGroups = append(actual.SecurityGroups, &SecurityGroup{ID: sg.GroupId})
	}

	associatePublicIpAddress := false
	for _, ni := range i.NetworkInterfaces {
		if aws.StringValue(ni.Association.PublicIp) != "" {
			associatePublicIpAddress = true
		}
	}
	actual.AssociatePublicIP = &associatePublicIpAddress

	if i.IamInstanceProfile != nil {
		actual.IAMInstanceProfile = &IAMInstanceProfile{Name: nameFromIAMARN(i.IamInstanceProfile.Arn)}
	}

	actual.Tags = mapEC2TagsToMap(i.Tags)

	e.ID = actual.ID

	// Avoid spurious changes on ImageId
	if e.ImageID != nil && actual.ImageID != nil && *actual.ImageID != *e.ImageID {
		image, err := cloud.ResolveImage(*e.ImageID)
		if err != nil {
			glog.Warningf("unable to resolve image: %q: %v", *e.ImageID, err)
		} else if image == nil {
			glog.Warningf("unable to resolve image: %q: not found", *e.ImageID)
		} else if aws.StringValue(image.ImageId) == *actual.ImageID {
			glog.V(4).Infof("Returning matching ImageId as expected name: %q -> %q", *actual.ImageID, *e.ImageID)
			actual.ImageID = e.ImageID
		}
	}

	return actual, nil
}

func nameFromIAMARN(arn *string) *string {
	if arn == nil {
		return nil
	}
	tokens := strings.Split(*arn, ":")
	last := tokens[len(tokens)-1]

	if !strings.HasPrefix(last, "instance-profile/") {
		glog.Warningf("Unexpected ARN for instance profile: %q", *arn)
	}

	name := strings.TrimPrefix(last, "instance-profile/")
	return &name
}

func (e *Instance) Run(c *fi.Context) error {
	cloud := c.Cloud.(awsup.AWSCloud)

	cloud.AddTags(e.Name, e.Tags)

	return fi.DefaultDeltaRunMethod(e, c)
}

func (_ *Instance) CheckChanges(a, e, changes *Instance) error {
	if a != nil {
		if e.Name == nil {
			return fi.RequiredField("Name")
		}
	}
	return nil
}

func (_ *Instance) RenderAWS(t *awsup.AWSAPITarget, a, e, changes *Instance) error {
	if a == nil {
		if e.ImageID == nil {
			return fi.RequiredField("ImageID")
		}
		image, err := t.Cloud.ResolveImage(*e.ImageID)
		if err != nil {
			return err
		}

		glog.V(2).Infof("Creating Instance with Name:%q", *e.Name)
		request := &ec2.RunInstancesInput{
			ImageId:      image.ImageId,
			InstanceType: e.InstanceType,
			MinCount:     aws.Int64(1),
			MaxCount:     aws.Int64(1),
		}

		if e.SSHKey != nil {
			request.KeyName = e.SSHKey.Name
		}

		securityGroupIDs := []*string{}
		for _, sg := range e.SecurityGroups {
			securityGroupIDs = append(securityGroupIDs, sg.ID)
		}
		request.NetworkInterfaces = []*ec2.InstanceNetworkInterfaceSpecification{
			{
				DeviceIndex:              aws.Int64(0),
				AssociatePublicIpAddress: e.AssociatePublicIP,
				SubnetId:                 e.Subnet.ID,
				PrivateIpAddress:         e.PrivateIPAddress,
				Groups:                   securityGroupIDs,
			},
		}

		// Build up the actual block device mappings
		// TODO: Support RootVolumeType & RootVolumeSize (see launchconfiguration)
		blockDeviceMappings, err := buildEphemeralDevices(e.InstanceType)
		if err != nil {
			return err
		}

		if len(blockDeviceMappings) != 0 {
			request.BlockDeviceMappings = []*ec2.BlockDeviceMapping{}
			for deviceName, bdm := range blockDeviceMappings {
				request.BlockDeviceMappings = append(request.BlockDeviceMappings, bdm.ToEC2(deviceName))
			}
		}

		if e.UserData != nil {
			d, err := fi.ResourceAsBytes(e.UserData)
			if err != nil {
				return fmt.Errorf("error rendering Instance UserData: %v", err)
			}
			if len(d) > MaxUserDataSize {
				// TODO: Re-enable gzip?
				// But it exposes some bugs in the AWS console, so if we can avoid it, we should
				//d, err = fi.GzipBytes(d)
				//if err != nil {
				//	return fmt.Errorf("error while gzipping UserData: %v", err)
				//}
				return fmt.Errorf("Instance UserData was too large (%d bytes)", len(d))
			}
			request.UserData = aws.String(base64.StdEncoding.EncodeToString(d))
		}

		if e.IAMInstanceProfile != nil {
			request.IamInstanceProfile = &ec2.IamInstanceProfileSpecification{
				Name: e.IAMInstanceProfile.Name,
			}
		}

		response, err := t.Cloud.EC2().RunInstances(request)
		if err != nil {
			return fmt.Errorf("error creating Instance: %v", err)
		}

		e.ID = response.Instances[0].InstanceId
	}

	return t.AddAWSTags(*e.ID, e.Tags)
}

func (e *Instance) TerraformLink() *terraform.Literal {
	return terraform.LiteralSelfLink("aws_instance", *e.Name)
}