cost-model/cloud/awsprovider.go

package cloud

import (
	"bytes"
	"compress/gzip"
	"encoding/csv"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"net/url"
	"os"
	"regexp"
	"strings"
	"time"

	"k8s.io/klog"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/awserr"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/athena"
	"github.com/aws/aws-sdk-go/service/ec2"
	"github.com/aws/aws-sdk-go/service/s3"
	"github.com/aws/aws-sdk-go/service/s3/s3manager"
	"github.com/jszwec/csvutil"

	v1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
)

const awsAccessKeyIDEnvVar = "AWS_ACCESS_KEY_ID"
const awsAccessKeySecretEnvVar = "AWS_SECRET_ACCESS_KEY"
const supportedSpotFeedVersion = "1"

// AWS represents an Amazon Provider
type AWS struct {
	Pricing                 map[string]*AWSProductTerms
	SpotPricingByInstanceID map[string]*spotInfo
	ValidPricingKeys        map[string]bool
	Clientset               *kubernetes.Clientset
	BaseCPUPrice            string
	BaseSpotCPUPrice        string
	BaseSpotRAMPrice        string
	SpotLabelName           string
	SpotLabelValue          string
	ServiceKeyName          string
	ServiceKeySecret        string
	SpotDataRegion          string
	SpotDataBucket          string
	SpotDataPrefix          string
	ProjectID               string
}

// AWSPricing maps a k8s node to an AWS Pricing "product"
type AWSPricing struct {
	Products map[string]*AWSProduct `json:"products"`
	Terms    AWSPricingTerms        `json:"terms"`
}

// AWSProduct represents a purchased SKU
type AWSProduct struct {
	Sku        string               `json:"sku"`
	Attributes AWSProductAttributes `json:"attributes"`
}

// AWSProductAttributes represents metadata about the product used to map to a node.
type AWSProductAttributes struct {
	Location        string `json:"location"`
	InstanceType    string `json:"instanceType"`
	Memory          string `json:"memory"`
	Storage         string `json:"storage"`
	VCpu            string `json:"vcpu"`
	UsageType       string `json:"usagetype"`
	OperatingSystem string `json:"operatingSystem"`
	PreInstalledSw  string `json:"preInstalledSw"`
}

// AWSPricingTerms are how you pay for the node: OnDemand, Reserved, or (TODO) Spot
type AWSPricingTerms struct {
	OnDemand map[string]map[string]*AWSOfferTerm `json:"OnDemand"`
	Reserved map[string]map[string]*AWSOfferTerm `json:"Reserved"`
}

// AWSOfferTerm is a sku extension used to pay for the node.
type AWSOfferTerm struct {
	Sku             string                  `json:"sku"`
	PriceDimensions map[string]*AWSRateCode `json:"priceDimensions"`
}

// AWSRateCode encodes data about the price of a product
type AWSRateCode struct {
	Unit         string          `json:"unit"`
	PricePerUnit AWSCurrencyCode `json:"pricePerUnit"`
}

// AWSCurrencyCode is the localized currency. (TODO: support non-USD)
type AWSCurrencyCode struct {
	USD string `json:"USD"`
}

// AWSProductTerms represents the full terms of the product
type AWSProductTerms struct {
	Sku      string        `json:"sku"`
	OnDemand *AWSOfferTerm `json:"OnDemand"`
	Reserved *AWSOfferTerm `json:"Reserved"`
	Memory   string        `json:"memory"`
	Storage  string        `json:"storage"`
	VCpu     string        `json:"vcpu"`
}

// ClusterIdEnvVar is the environment variable in which one can manually set the ClusterId
const ClusterIdEnvVar = "AWS_CLUSTER_ID"

// OnDemandRateCode is appended to an node sku
const OnDemandRateCode = ".JRTCKXETXF"

// ReservedRateCode is appended to a node sku
const ReservedRateCode = ".38NPMPTW36"

// HourlyRateCode is appended to a node sku
const HourlyRateCode = ".6YS6EN2CT7"

// KubeAttrConversion maps the k8s labels for region to an aws region
func (aws *AWS) KubeAttrConversion(location, instanceType, operatingSystem string) string {
	locationToRegion := map[string]string{
		"US East (Ohio)":             "us-east-2",
		"US East (N. Virginia)":      "us-east-1",
		"US West (N. California)":    "us-west-1",
		"US West (Oregon)":           "us-west-2",
		"Asia Pacific (Mumbai)":      "ap-south-1",
		"Asia Pacific (Osaka-Local)": "ap-northeast-3",
		"Asia Pacific (Seoul)":       "ap-northeast-2",
		"Asia Pacific (Singapore)":   "ap-southeast-1",
		"Asia Pacific (Sydney)":      "ap-southeast-2",
		"Asia Pacific (Tokyo)":       "ap-northeast-1",
		"Canada (Central)":           "ca-central-1",
		"China (Beijing)":            "cn-north-1",
		"China (Ningxia)":            "cn-northwest-1",
		"EU (Frankfurt)":             "eu-central-1",
		"EU (Ireland)":               "eu-west-1",
		"EU (London)":                "eu-west-2",
		"EU (Paris)":                 "eu-west-3",
		"EU (Stockholm)":             "eu-north-1",
		"South America (São Paulo)":  "sa-east-1",
		"AWS GovCloud (US-East)":     "us-gov-east-1",
		"AWS GovCloud (US)":          "us-gov-west-1",
	}

	operatingSystem = strings.ToLower(operatingSystem)

	region := locationToRegion[location]
	return region + "," + instanceType + "," + operatingSystem
}

type awsKey struct {
	SpotLabelName  string
	SpotLabelValue string
	Labels         map[string]string
	ProviderID     string
}

func (k *awsKey) ID() string {
	provIdRx := regexp.MustCompile("aws:///([^/]+)/([^/]+)") // It's of the form aws:///us-east-2a/i-0fea4fd46592d050b and we want i-0fea4fd46592d050b, if it exists
	for matchNum, group := range provIdRx.FindStringSubmatch(k.ProviderID) {
		if matchNum == 2 {
			return group
		}
	}
	klog.V(3).Info("Could not find instance ID in " + k.ProviderID)
	return ""
}

func (k *awsKey) Features() string {

	instanceType := k.Labels[v1.LabelInstanceType]
	var operatingSystem string
	operatingSystem, ok := k.Labels[v1.LabelOSStable]
	if !ok {
		operatingSystem = k.Labels["beta.kubernetes.io/os"]
	}
	region := k.Labels[v1.LabelZoneRegion]

	key := region + "," + instanceType + "," + operatingSystem
	usageType := "preemptible"
	spotKey := key + "," + usageType
	if l, ok := k.Labels["lifecycle"]; ok && l == "EC2Spot" {
		return spotKey
	}
	if l, ok := k.Labels[k.SpotLabelName]; ok && l == k.SpotLabelValue {
		return spotKey
	}
	return region + "," + instanceType + "," + operatingSystem
}

// GetKey maps node labels to information needed to retrieve pricing data
func (aws *AWS) GetKey(labels map[string]string) Key {
	return &awsKey{
		SpotLabelName:  aws.SpotLabelName,
		SpotLabelValue: aws.SpotLabelValue,
		Labels:         labels,
		ProviderID:     labels["providerID"],
	}
}

func (aws *AWS) isPreemptible(key string) bool {
	s := strings.Split(key, ",")
	if len(s) == 4 && s[3] == "preemptible" {
		return true
	}
	return false
}

// DownloadPricingData fetches data from the AWS Pricing API
func (aws *AWS) DownloadPricingData() error {

	nodeList, err := aws.Clientset.CoreV1().Nodes().List(metav1.ListOptions{})
	if err != nil {
		return err
	}
	inputkeys := make(map[string]bool)
	for _, n := range nodeList.Items {
		labels := n.GetObjectMeta().GetLabels()
		key := aws.GetKey(labels)
		inputkeys[key.Features()] = true
	}

	aws.Pricing = make(map[string]*AWSProductTerms)
	aws.ValidPricingKeys = make(map[string]bool)
	skusToKeys := make(map[string]string)

	pricingURL := "https://pricing.us-east-1.amazonaws.com/offers/v1.0/aws/AmazonEC2/current/index.json"
	klog.V(2).Infof("starting download of \"%s\", which is quite large ...", pricingURL)
	resp, err := http.Get(pricingURL)
	if err != nil {
		klog.V(2).Infof("Bogus fetch of \"%s\": %v", pricingURL, err)
		return err
	}

	dec := json.NewDecoder(resp.Body)
	for {
		t, err := dec.Token()
		if err == io.EOF {
			klog.V(2).Infof("done loading \"%s\"\n", pricingURL)
			break
		}
		if t == "products" {
			dec.Token() //{
			for dec.More() {
				dec.Token() // the sku token
				product := &AWSProduct{}
				err := dec.Decode(&product)

				if err != nil {
					klog.V(1).Infof("Error parsing response from \"%s\": %v", pricingURL, err.Error())
					break
				}
				if product.Attributes.PreInstalledSw == "NA" &&
					(strings.HasPrefix(product.Attributes.UsageType, "BoxUsage") || strings.Contains(product.Attributes.UsageType, "-BoxUsage")) {
					key := aws.KubeAttrConversion(product.Attributes.Location, product.Attributes.InstanceType, product.Attributes.OperatingSystem)
					spotKey := key + ",preemptible"
					if inputkeys[key] || inputkeys[spotKey] { // Just grab the sku even if spot, and change the price later.
						productTerms := &AWSProductTerms{
							Sku:     product.Sku,
							Memory:  product.Attributes.Memory,
							Storage: product.Attributes.Storage,
							VCpu:    product.Attributes.VCpu,
						}
						aws.Pricing[key] = productTerms
						aws.Pricing[spotKey] = productTerms
						skusToKeys[product.Sku] = key
					}
					aws.ValidPricingKeys[key] = true
					aws.ValidPricingKeys[spotKey] = true
				}
			}
		}
		if t == "terms" {
			dec.Token()
			termType, _ := dec.Token()
			if termType == "OnDemand" {
				dec.Token()
				for dec.More() {
					sku, _ := dec.Token()
					dec.Token()
					skuOnDemand, _ := dec.Token()
					offerTerm := &AWSOfferTerm{}
					err := dec.Decode(&offerTerm)
					if err != nil {
						klog.V(1).Infof("Error decoding AWS Offer Term: " + err.Error())
					}
					if sku.(string)+OnDemandRateCode == skuOnDemand {
						key, ok := skusToKeys[sku.(string)]
						spotKey := key + ",preemptible"
						if ok {
							aws.Pricing[key].OnDemand = offerTerm
							aws.Pricing[spotKey].OnDemand = offerTerm
						}
					}
					dec.Token()
				}
				dec.Token()
			}
		}
	}

	if err != nil {
		return err
	}
	c, err := GetDefaultPricingData("aws.json")
	if err != nil {
		klog.V(1).Infof("Error downloading default pricing data: %s", err.Error())
	}
	aws.BaseCPUPrice = c.CPU
	aws.BaseSpotCPUPrice = c.SpotCPU
	aws.BaseSpotRAMPrice = c.SpotRAM
	aws.SpotLabelName = c.SpotLabel
	aws.SpotLabelValue = c.SpotLabelValue
	aws.SpotDataBucket = c.SpotDataBucket
	aws.SpotDataPrefix = c.SpotDataPrefix
	aws.ProjectID = c.ProjectID
	aws.SpotDataRegion = c.SpotDataRegion
	aws.ServiceKeyName = c.ServiceKeyName
	aws.ServiceKeySecret = c.ServiceKeySecret

	sp, err := parseSpotData(aws.SpotDataBucket, aws.SpotDataPrefix, aws.ProjectID, aws.SpotDataRegion, aws.ServiceKeyName, aws.ServiceKeySecret)
	if err != nil {
		klog.V(1).Infof("Error downloading spot data %s", err.Error())
	} else {
		aws.SpotPricingByInstanceID = sp
	}

	return nil
}

// AllNodePricing returns all the billing data fetched.
func (aws *AWS) AllNodePricing() (interface{}, error) {
	return aws.Pricing, nil
}

func (aws *AWS) createNode(terms *AWSProductTerms, usageType string, k Key) (*Node, error) {
	key := k.Features()
	if aws.isPreemptible(key) {
		if spotInfo, ok := aws.SpotPricingByInstanceID[k.ID()]; ok { // try and match directly to an ID for pricing. We'll still need the features
			var spotcost string
			arr := strings.Split(spotInfo.Charge, " ")
			if len(arr) == 2 {
				spotcost = arr[0]
			} else {
				klog.V(2).Infof("Spot data for node %s is missing", k.ID())
			}
			return &Node{
				Cost:         spotcost,
				VCPU:         terms.VCpu,
				RAM:          terms.Memory,
				Storage:      terms.Storage,
				BaseCPUPrice: aws.BaseCPUPrice,
				UsageType:    usageType,
			}, nil
		}
		return &Node{
			VCPU:         terms.VCpu,
			VCPUCost:     aws.BaseSpotCPUPrice,
			RAM:          terms.Memory,
			RAMCost:      aws.BaseSpotRAMPrice,
			Storage:      terms.Storage,
			BaseCPUPrice: aws.BaseCPUPrice,
			UsageType:    usageType,
		}, nil
	}
	cost := terms.OnDemand.PriceDimensions[terms.Sku+OnDemandRateCode+HourlyRateCode].PricePerUnit.USD
	return &Node{
		Cost:         cost,
		VCPU:         terms.VCpu,
		RAM:          terms.Memory,
		Storage:      terms.Storage,
		BaseCPUPrice: aws.BaseCPUPrice,
		UsageType:    usageType,
	}, nil
}

// NodePricing takes in a key from GetKey and returns a Node object for use in building the cost model.
func (aws *AWS) NodePricing(k Key) (*Node, error) {
	//return json.Marshal(aws.Pricing[key])
	key := k.Features()
	usageType := "ondemand"
	if aws.isPreemptible(key) {
		usageType = "preemptible"
	}

	terms, ok := aws.Pricing[key]
	if ok {
		return aws.createNode(terms, usageType, k)
	} else if _, ok := aws.ValidPricingKeys[key]; ok {
		err := aws.DownloadPricingData()
		if err != nil {
			return nil, err
		}
		terms, termsOk := aws.Pricing[key]
		if !termsOk {
			return nil, fmt.Errorf("Unable to find any Pricing data for \"%s\"", key)
		}
		return aws.createNode(terms, usageType, k)
	} else {
		return nil, fmt.Errorf("Invalid Pricing Key \"%s\"", key)
	}
}

// ClusterName returns an object that represents the cluster. TODO: actually return the name of the cluster. Blocked on cluster federation.
func (awsProvider *AWS) ClusterName() ([]byte, error) {
	defaultClusterName := "AWS Cluster #1"
	makeStructure := func(clusterName string) ([]byte, error) {
		klog.V(2).Infof("Returning \"%s\" as ClusterName", clusterName)
		m := make(map[string]string)
		m["name"] = clusterName
		m["provider"] = "AWS"
		return json.Marshal(m)
	}

	maybeClusterId := os.Getenv(ClusterIdEnvVar)
	if len(maybeClusterId) != 0 {
		return makeStructure(maybeClusterId)
	}
	provIdRx := regexp.MustCompile("aws:///([^/]+)/([^/]+)")
	clusterIdRx := regexp.MustCompile("^kubernetes\\.io/cluster/([^/]+)")
	nodeList, err := awsProvider.Clientset.CoreV1().Nodes().List(metav1.ListOptions{})
	if err != nil {
		return nil, err
	}
	for _, n := range nodeList.Items {
		region := ""
		instanceId := ""
		providerId := n.Spec.ProviderID
		for matchNum, group := range provIdRx.FindStringSubmatch(providerId) {
			if matchNum == 1 {
				region = group
			} else if matchNum == 2 {
				instanceId = group
			}
		}
		if len(instanceId) == 0 {
			klog.V(2).Infof("Unable to decode Node.ProviderID \"%s\", skipping it", providerId)
			continue
		}
		c := &aws.Config{
			Region: aws.String(region),
		}
		s := session.Must(session.NewSession(c))
		ec2Svc := ec2.New(s)
		di, diErr := ec2Svc.DescribeInstances(&ec2.DescribeInstancesInput{
			InstanceIds: []*string{
				aws.String(instanceId),
			},
		})
		if diErr != nil {
			// maybe log this?
			continue
		}
		if len(di.Reservations) != 1 {
			klog.V(2).Infof("Expected 1 Reservation back from DescribeInstances(%s), received %d", instanceId, len(di.Reservations))
			continue
		}
		res := di.Reservations[0]
		if len(res.Instances) != 1 {
			klog.V(2).Infof("Expected 1 Instance back from DescribeInstances(%s), received %d", instanceId, len(res.Instances))
			continue
		}
		inst := res.Instances[0]
		for _, tag := range inst.Tags {
			tagKey := *tag.Key
			for matchNum, group := range clusterIdRx.FindStringSubmatch(tagKey) {
				if matchNum != 1 {
					continue
				}
				return makeStructure(group)
			}
		}
	}
	klog.V(2).Infof("Unable to sniff out cluster ID, perhaps set $%s to force one", ClusterIdEnvVar)
	return makeStructure(defaultClusterName)
}

// AddServiceKey adds an AWS service key, useful for pulling down out-of-cluster costs. Optional-- the container this runs in can be directly authorized.
func (*AWS) AddServiceKey(formValues url.Values) error {
	keyID := formValues.Get("access_key_ID")
	key := formValues.Get("secret_access_key")
	m := make(map[string]string)
	m["access_key_ID"] = keyID
	m["secret_access_key"] = key
	result, err := json.Marshal(m)
	if err != nil {
		return err
	}
	return ioutil.WriteFile("/var/configs/key.json", result, 0644)
}

// GetDisks returns the AWS disks backing PVs. Useful because sometimes k8s will not clean up PVs correctly. Requires a json config in /var/configs with key region.
func (*AWS) GetDisks() ([]byte, error) {
	jsonFile, err := os.Open("/var/configs/key.json")
	if err == nil {
		byteValue, _ := ioutil.ReadAll(jsonFile)
		var result map[string]string
		err := json.Unmarshal([]byte(byteValue), &result)
		if err != nil {
			return nil, err
		}
		err = os.Setenv(awsAccessKeyIDEnvVar, result["access_key_ID"])
		if err != nil {
			return nil, err
		}
		err = os.Setenv(awsAccessKeySecretEnvVar, result["secret_access_key"])
		if err != nil {
			return nil, err
		}
	} else if os.IsNotExist(err) {
		klog.V(2).Infof("Using Default Credentials")
	} else {
		return nil, err
	}
	defer jsonFile.Close()
	clusterConfig, err := os.Open("/var/configs/cluster.json")
	if err != nil {
		return nil, err
	}
	defer clusterConfig.Close()
	b, err := ioutil.ReadAll(clusterConfig)
	if err != nil {
		return nil, err
	}
	var clusterConf map[string]string
	err = json.Unmarshal([]byte(b), &clusterConf)
	if err != nil {
		return nil, err
	}
	region := aws.String(clusterConf["region"])
	c := &aws.Config{
		Region: region,
	}
	s := session.Must(session.NewSession(c))

	ec2Svc := ec2.New(s)
	input := &ec2.DescribeVolumesInput{}
	volumeResult, err := ec2Svc.DescribeVolumes(input)
	if err != nil {
		if aerr, ok := err.(awserr.Error); ok {
			switch aerr.Code() {
			default:
				return nil, aerr
			}
		} else {
			return nil, err
		}
	}
	return json.Marshal(volumeResult)
}

// QuerySQL can query a properly configured Athena database.
// Used to fetch billing data.
// Requires a json config in /var/configs with key region, output, and database.
func (*AWS) QuerySQL(query string) ([]byte, error) {
	jsonFile, err := os.Open("/var/configs/key.json")
	if err == nil {
		byteValue, _ := ioutil.ReadAll(jsonFile)
		var result map[string]string
		json.Unmarshal([]byte(byteValue), &result)
		err = os.Setenv(awsAccessKeyIDEnvVar, result["access_key_ID"])
		if err != nil {
			return nil, err
		}
		err = os.Setenv(awsAccessKeySecretEnvVar, result["secret_access_key"])
		if err != nil {
			return nil, err
		}
	} else if os.IsNotExist(err) {
		klog.V(2).Infof("Using Default Credentials")
	} else {
		return nil, err
	}
	defer jsonFile.Close()
	athenaConfigs, err := os.Open("/var/configs/athena.json")
	if err != nil {
		return nil, err
	}
	defer athenaConfigs.Close()
	b, err := ioutil.ReadAll(athenaConfigs)
	if err != nil {
		return nil, err
	}
	var athenaConf map[string]string
	json.Unmarshal([]byte(b), &athenaConf)
	region := aws.String(athenaConf["region"])
	resultsBucket := athenaConf["output"]
	database := athenaConf["database"]

	c := &aws.Config{
		Region: region,
	}
	s := session.Must(session.NewSession(c))
	svc := athena.New(s)

	var e athena.StartQueryExecutionInput

	var r athena.ResultConfiguration
	r.SetOutputLocation(resultsBucket)
	e.SetResultConfiguration(&r)

	e.SetQueryString(query)
	var q athena.QueryExecutionContext
	q.SetDatabase(database)
	e.SetQueryExecutionContext(&q)

	res, err := svc.StartQueryExecution(&e)
	if err != nil {
		return nil, err
	}

	klog.V(2).Infof("StartQueryExecution result:")
	klog.V(2).Infof(res.GoString())

	var qri athena.GetQueryExecutionInput
	qri.SetQueryExecutionId(*res.QueryExecutionId)

	var qrop *athena.GetQueryExecutionOutput
	duration := time.Duration(2) * time.Second // Pause for 2 seconds

	for {
		qrop, err = svc.GetQueryExecution(&qri)
		if err != nil {
			return nil, err
		}
		if *qrop.QueryExecution.Status.State != "RUNNING" {
			break
		}
		time.Sleep(duration)
	}
	if *qrop.QueryExecution.Status.State == "SUCCEEDED" {

		var ip athena.GetQueryResultsInput
		ip.SetQueryExecutionId(*res.QueryExecutionId)

		op, err := svc.GetQueryResults(&ip)
		if err != nil {
			return nil, err
		}
		b, err := json.Marshal(op.ResultSet)
		if err != nil {
			return nil, err
		}

		return b, nil
	}
	return nil, fmt.Errorf("Error getting query results : %s", *qrop.QueryExecution.Status.State)

}

type spotInfo struct {
	Timestamp   string `csv:"Timestamp"`
	UsageType   string `csv:"UsageType"`
	Operation   string `csv:"Operation"`
	InstanceID  string `csv:"InstanceID"`
	MyBidID     string `csv:"MyBidID"`
	MyMaxPrice  string `csv:"MyMaxPrice"`
	MarketPrice string `csv:"MarketPrice"`
	Charge      string `csv:"Charge"`
	Version     string `csv:"Version"`
}

type fnames []*string

func (f fnames) Len() int {
	return len(f)
}

func (f fnames) Swap(i, j int) {
	f[i], f[j] = f[j], f[i]
}

func (f fnames) Less(i, j int) bool {
	key1 := strings.Split(*f[i], ".")
	key2 := strings.Split(*f[j], ".")

	t1, err := time.Parse("2006-01-02-15", key1[1])
	if err != nil {
		klog.V(1).Info("Unable to parse timestamp" + key1[1])
		return false
	}
	t2, err := time.Parse("2006-01-02-15", key2[1])
	if err != nil {
		klog.V(1).Info("Unable to parse timestamp" + key2[1])
		return false
	}
	return t1.Before(t2)
}

func parseSpotData(bucket string, prefix string, projectID string, region string, accessKeyID string, accessKeySecret string) (map[string]*spotInfo, error) {

	if accessKeyID != "" && accessKeySecret != "" { // credentials may exist on the actual AWS node-- if so, use those. If not, override with the service key
		err := os.Setenv(awsAccessKeyIDEnvVar, accessKeyID)
		if err != nil {
			return nil, err
		}
		err = os.Setenv(awsAccessKeySecretEnvVar, accessKeySecret)
		if err != nil {
			return nil, err
		}
	}

	c := aws.NewConfig().WithRegion(region)

	s := session.Must(session.NewSession(c))
	s3Svc := s3.New(s)
	downloader := s3manager.NewDownloaderWithClient(s3Svc)

	tNow := time.Now()
	tOneDayAgo := tNow.Add(time.Duration(-24) * time.Hour) // Also get files from one day ago to avoid boundary conditions
	ls := &s3.ListObjectsInput{
		Bucket: aws.String(bucket),
		Prefix: aws.String(prefix + "/" + projectID + "." + tOneDayAgo.Format("2006-01-02")),
	}
	ls2 := &s3.ListObjectsInput{
		Bucket: aws.String(bucket),
		Prefix: aws.String(prefix + "/" + projectID + "." + tNow.Format("2006-01-02")),
	}
	lso, err := s3Svc.ListObjects(ls)
	if err != nil {
		return nil, err
	}
	klog.V(2).Infof("Found %s files from yesterday", string(len(lso.Contents)))
	lso2, err := s3Svc.ListObjects(ls2)
	if err != nil {
		return nil, err
	}
	klog.V(2).Infof("Found %s files from today", string(len(lso.Contents)))

	var keys []*string
	for _, obj := range lso.Contents {
		keys = append(keys, obj.Key)
	}
	for _, obj := range lso2.Contents {
		keys = append(keys, obj.Key)
	}

	spots := make(map[string]*spotInfo)
	for _, key := range keys {
		getObj := &s3.GetObjectInput{
			Bucket: aws.String(bucket),
			Key:    key,
		}

		buf := aws.NewWriteAtBuffer([]byte{})
		_, err := downloader.Download(buf, getObj)
		if err != nil {
			return nil, err
		}

		r := bytes.NewReader(buf.Bytes())

		gr, err := gzip.NewReader(r)
		if err != nil {
			return nil, err
		}

		csvReader := csv.NewReader(gr)
		csvReader.Comma = '\t'
		header, err := csvutil.Header(spotInfo{}, "csv")
		if err != nil {
			return nil, err
		}
		dec, err := csvutil.NewDecoder(csvReader, header...)
		if err != nil {
			return nil, err
		}

		for {
			if err := dec.Decode(&spotInfo{}); err == io.EOF {
				break
			}
			st := dec.Record()
			if len(st) == 9 { // it's tab separated but not quite a tsv
				klog.V(3).Infof("Found spot info %+v", st)
				spot := &spotInfo{
					Timestamp:   st[0],
					UsageType:   st[1],
					Operation:   st[2],
					InstanceID:  st[3],
					MyBidID:     st[4],
					MyMaxPrice:  st[5],
					MarketPrice: st[6],
					Charge:      st[7],
					Version:     st[8],
				}
				if spot.Version != supportedSpotFeedVersion {
					klog.V(1).Infof("Possibly unsupported spot data feed version " + spot.Version)
				}
				spots[spot.InstanceID] = spot
			}
		}
		gr.Close()
	}
	return spots, nil
}