open-nomad/client/fingerprint/env_aws.go

251 lines
6.6 KiB
Go

package fingerprint
import (
"fmt"
"io/ioutil"
"log"
"net/http"
"net/url"
"os"
"regexp"
"strings"
"time"
"github.com/hashicorp/go-cleanhttp"
"github.com/hashicorp/nomad/client/config"
"github.com/hashicorp/nomad/nomad/structs"
)
// This is where the AWS metadata server normally resides. We hardcode the
// "instance" path as well since it's the only one we access here.
const DEFAULT_AWS_URL = "http://169.254.169.254/latest/meta-data/"
// map of instance type to approximate speed, in Mbits/s
// http://serverfault.com/questions/324883/aws-bandwidth-and-content-delivery/326797#326797
// which itself cites these sources:
// - http://blog.rightscale.com/2007/10/28/network-performance-within-amazon-ec2-and-to-amazon-s3/
// - http://www.soc.napier.ac.uk/~bill/chris_p.pdf
//
// This data is meant for a loose approximation
var ec2InstanceSpeedMap = map[string]int{
"m4.large": 80,
"m3.medium": 80,
"m3.large": 80,
"c4.large": 80,
"c3.large": 80,
"c3.xlarge": 80,
"r3.large": 80,
"r3.xlarge": 80,
"i2.xlarge": 80,
"d2.xlarge": 80,
"t2.micro": 16,
"t2.small": 16,
"t2.medium": 16,
"t2.large": 16,
"m4.xlarge": 760,
"m4.2xlarge": 760,
"m4.4xlarge": 760,
"m3.xlarge": 760,
"m3.2xlarge": 760,
"c4.xlarge": 760,
"c4.2xlarge": 760,
"c4.4xlarge": 760,
"c3.2xlarge": 760,
"c3.4xlarge": 760,
"g2.2xlarge": 760,
"r3.2xlarge": 760,
"r3.4xlarge": 760,
"i2.2xlarge": 760,
"i2.4xlarge": 760,
"d2.2xlarge": 760,
"d2.4xlarge": 760,
"m4.10xlarge": 10000,
"c4.8xlarge": 10000,
"c3.8xlarge": 10000,
"g2.8xlarge": 10000,
"r3.8xlarge": 10000,
"i2.8xlarge": 10000,
"d2.8xlarge": 10000,
}
// EnvAWSFingerprint is used to fingerprint AWS metadata
type EnvAWSFingerprint struct {
StaticFingerprinter
logger *log.Logger
}
// NewEnvAWSFingerprint is used to create a fingerprint from AWS metadata
func NewEnvAWSFingerprint(logger *log.Logger) Fingerprint {
f := &EnvAWSFingerprint{logger: logger}
return f
}
func (f *EnvAWSFingerprint) Fingerprint(cfg *config.Config, node *structs.Node) (bool, error) {
if !f.isAWS() {
return false, nil
}
// newNetwork is populated and addded to the Nodes resources
newNetwork := &structs.NetworkResource{
Device: "eth0",
}
if node.Links == nil {
node.Links = make(map[string]string)
}
metadataURL := os.Getenv("AWS_ENV_URL")
if metadataURL == "" {
metadataURL = DEFAULT_AWS_URL
}
// assume 2 seconds is enough time for inside AWS network
client := &http.Client{
Timeout: 2 * time.Second,
Transport: cleanhttp.DefaultTransport(),
}
// Keys and whether they should be namespaced as unique. Any key whose value
// uniquely identifies a node, such as ip, should be marked as unique. When
// marked as unique, the key isn't included in the computed node class.
keys := map[string]bool{
"ami-id": true,
"hostname": true,
"instance-id": true,
"instance-type": false,
"local-hostname": true,
"local-ipv4": true,
"public-hostname": true,
"public-ipv4": true,
"placement/availability-zone": false,
}
for k, unique := range keys {
res, err := client.Get(metadataURL + k)
if res.StatusCode != http.StatusOK {
f.logger.Printf("[WARN]: fingerprint.env_aws: Could not read value for attribute %q", k)
continue
}
if err != nil {
// if it's a URL error, assume we're not in an AWS environment
// TODO: better way to detect AWS? Check xen virtualization?
if _, ok := err.(*url.Error); ok {
return false, nil
}
// not sure what other errors it would return
return false, err
}
resp, err := ioutil.ReadAll(res.Body)
res.Body.Close()
if err != nil {
f.logger.Printf("[ERR]: fingerprint.env_aws: Error reading response body for AWS %s", k)
}
// assume we want blank entries
key := "platform.aws." + strings.Replace(k, "/", ".", -1)
if unique {
key = structs.UniqueNamespace(key)
}
node.Attributes[key] = strings.Trim(string(resp), "\n")
}
// copy over network specific information
if val := node.Attributes["unique.platform.aws.local-ipv4"]; val != "" {
node.Attributes["unique.network.ip-address"] = val
newNetwork.IP = val
newNetwork.CIDR = newNetwork.IP + "/32"
}
// find LinkSpeed from lookup
if throughput := f.linkSpeed(); throughput > 0 {
newNetwork.MBits = throughput
}
if node.Resources == nil {
node.Resources = &structs.Resources{}
}
node.Resources.Networks = append(node.Resources.Networks, newNetwork)
// populate Node Network Resources
// populate Links
node.Links["aws.ec2"] = fmt.Sprintf("%s.%s",
node.Attributes["platform.aws.placement.availability-zone"],
node.Attributes["unique.platform.aws.instance-id"])
return true, nil
}
func (f *EnvAWSFingerprint) isAWS() bool {
// Read the internal metadata URL from the environment, allowing test files to
// provide their own
metadataURL := os.Getenv("AWS_ENV_URL")
if metadataURL == "" {
metadataURL = DEFAULT_AWS_URL
}
// assume 2 seconds is enough time for inside AWS network
client := &http.Client{
Timeout: 2 * time.Second,
Transport: cleanhttp.DefaultTransport(),
}
// Query the metadata url for the ami-id, to veryify we're on AWS
resp, err := client.Get(metadataURL + "ami-id")
if err != nil {
f.logger.Printf("[DEBUG] fingerprint.env_aws: Error querying AWS Metadata URL, skipping")
return false
}
defer resp.Body.Close()
if resp.StatusCode >= 400 {
// URL not found, which indicates that this isn't AWS
return false
}
instanceID, err := ioutil.ReadAll(resp.Body)
if err != nil {
f.logger.Printf("[DEBUG] fingerprint.env_aws: Error reading AWS Instance ID, skipping")
return false
}
match, err := regexp.MatchString("ami-*", string(instanceID))
if !match {
return false
}
return true
}
// EnvAWSFingerprint uses lookup table to approximate network speeds
func (f *EnvAWSFingerprint) linkSpeed() int {
// Query the API for the instance type, and use the table above to approximate
// the network speed
metadataURL := os.Getenv("AWS_ENV_URL")
if metadataURL == "" {
metadataURL = DEFAULT_AWS_URL
}
// assume 2 seconds is enough time for inside AWS network
client := &http.Client{
Timeout: 2 * time.Second,
Transport: cleanhttp.DefaultTransport(),
}
res, err := client.Get(metadataURL + "instance-type")
body, err := ioutil.ReadAll(res.Body)
res.Body.Close()
if err != nil {
f.logger.Printf("[ERR]: fingerprint.env_aws: Error reading response body for instance-type")
return 0
}
key := strings.Trim(string(body), "\n")
v, ok := ec2InstanceSpeedMap[key]
if !ok {
return 0
}
return v
}