telegraf/plugins/outputs/cloudwatch/cloudwatch.go

276 lines
6.3 KiB
Go

package cloudwatch
import (
"log"
"math"
"sort"
"strings"
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/service/cloudwatch"
"github.com/aws/aws-sdk-go/service/sts"
"github.com/influxdata/telegraf"
internalaws "github.com/influxdata/telegraf/internal/config/aws"
"github.com/influxdata/telegraf/plugins/outputs"
)
type CloudWatch struct {
Region string `toml:"region"`
AccessKey string `toml:"access_key"`
SecretKey string `toml:"secret_key"`
RoleARN string `toml:"role_arn"`
Profile string `toml:"profile"`
Filename string `toml:"shared_credential_file"`
Token string `toml:"token"`
Namespace string `toml:"namespace"` // CloudWatch Metrics Namespace
svc *cloudwatch.CloudWatch
}
var sampleConfig = `
## Amazon REGION
region = "us-east-1"
## Amazon Credentials
## Credentials are loaded in the following order
## 1) Assumed credentials via STS if role_arn is specified
## 2) explicit credentials from 'access_key' and 'secret_key'
## 3) shared profile from 'profile'
## 4) environment variables
## 5) shared credentials file
## 6) EC2 Instance Profile
#access_key = ""
#secret_key = ""
#token = ""
#role_arn = ""
#profile = ""
#shared_credential_file = ""
## Namespace for the CloudWatch MetricDatums
namespace = "InfluxData/Telegraf"
`
func (c *CloudWatch) SampleConfig() string {
return sampleConfig
}
func (c *CloudWatch) Description() string {
return "Configuration for AWS CloudWatch output."
}
func (c *CloudWatch) Connect() error {
credentialConfig := &internalaws.CredentialConfig{
Region: c.Region,
AccessKey: c.AccessKey,
SecretKey: c.SecretKey,
RoleARN: c.RoleARN,
Profile: c.Profile,
Filename: c.Filename,
Token: c.Token,
}
configProvider := credentialConfig.Credentials()
stsService := sts.New(configProvider)
params := &sts.GetSessionTokenInput{}
_, err := stsService.GetSessionToken(params)
if err != nil {
log.Printf("E! cloudwatch: Cannot use credentials to connect to AWS : %+v \n", err.Error())
return err
}
c.svc = cloudwatch.New(configProvider)
return nil
}
func (c *CloudWatch) Close() error {
return nil
}
func (c *CloudWatch) Write(metrics []telegraf.Metric) error {
for _, m := range metrics {
err := c.WriteSinglePoint(m)
if err != nil {
return err
}
}
return nil
}
// Write data for a single point. A point can have many fields and one field
// is equal to one MetricDatum. There is a limit on how many MetricDatums a
// request can have so we process one Point at a time.
func (c *CloudWatch) WriteSinglePoint(point telegraf.Metric) error {
datums := BuildMetricDatum(point)
const maxDatumsPerCall = 20 // PutMetricData only supports up to 20 data metrics per call
for _, partition := range PartitionDatums(maxDatumsPerCall, datums) {
err := c.WriteToCloudWatch(partition)
if err != nil {
return err
}
}
return nil
}
func (c *CloudWatch) WriteToCloudWatch(datums []*cloudwatch.MetricDatum) error {
params := &cloudwatch.PutMetricDataInput{
MetricData: datums,
Namespace: aws.String(c.Namespace),
}
_, err := c.svc.PutMetricData(params)
if err != nil {
log.Printf("E! CloudWatch: Unable to write to CloudWatch : %+v \n", err.Error())
}
return err
}
// Partition the MetricDatums into smaller slices of a max size so that are under the limit
// for the AWS API calls.
func PartitionDatums(size int, datums []*cloudwatch.MetricDatum) [][]*cloudwatch.MetricDatum {
numberOfPartitions := len(datums) / size
if len(datums)%size != 0 {
numberOfPartitions += 1
}
partitions := make([][]*cloudwatch.MetricDatum, numberOfPartitions)
for i := 0; i < numberOfPartitions; i++ {
start := size * i
end := size * (i + 1)
if end > len(datums) {
end = len(datums)
}
partitions[i] = datums[start:end]
}
return partitions
}
// Make a MetricDatum for each field in a Point. Only fields with values that can be
// converted to float64 are supported. Non-supported fields are skipped.
func BuildMetricDatum(point telegraf.Metric) []*cloudwatch.MetricDatum {
datums := make([]*cloudwatch.MetricDatum, len(point.Fields()))
i := 0
var value float64
for k, v := range point.Fields() {
switch t := v.(type) {
case int:
value = float64(t)
case int32:
value = float64(t)
case int64:
value = float64(t)
case float64:
value = t
case bool:
if t {
value = 1
} else {
value = 0
}
case time.Time:
value = float64(t.Unix())
default:
// Skip unsupported type.
datums = datums[:len(datums)-1]
continue
}
// Do CloudWatch boundary checking
// Constraints at: http://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_MetricDatum.html
if math.IsNaN(value) {
datums = datums[:len(datums)-1]
continue
}
if math.IsInf(value, 0) {
datums = datums[:len(datums)-1]
continue
}
if value > 0 && value < float64(8.515920e-109) {
datums = datums[:len(datums)-1]
continue
}
if value > float64(1.174271e+108) {
datums = datums[:len(datums)-1]
continue
}
datums[i] = &cloudwatch.MetricDatum{
MetricName: aws.String(strings.Join([]string{point.Name(), k}, "_")),
Value: aws.Float64(value),
Dimensions: BuildDimensions(point.Tags()),
Timestamp: aws.Time(point.Time()),
}
i += 1
}
return datums
}
// Make a list of Dimensions by using a Point's tags. CloudWatch supports up to
// 10 dimensions per metric so we only keep up to the first 10 alphabetically.
// This always includes the "host" tag if it exists.
func BuildDimensions(mTags map[string]string) []*cloudwatch.Dimension {
const MaxDimensions = 10
dimensions := make([]*cloudwatch.Dimension, int(math.Min(float64(len(mTags)), MaxDimensions)))
i := 0
// This is pretty ugly but we always want to include the "host" tag if it exists.
if host, ok := mTags["host"]; ok {
dimensions[i] = &cloudwatch.Dimension{
Name: aws.String("host"),
Value: aws.String(host),
}
i += 1
}
var keys []string
for k := range mTags {
if k != "host" {
keys = append(keys, k)
}
}
sort.Strings(keys)
for _, k := range keys {
if i >= MaxDimensions {
break
}
dimensions[i] = &cloudwatch.Dimension{
Name: aws.String(k),
Value: aws.String(mTags[k]),
}
i += 1
}
return dimensions
}
func init() {
outputs.Add("cloudwatch", func() telegraf.Output {
return &CloudWatch{}
})
}