open-nomad/client/fingerprint/env_aws.go

290 lines
8.4 KiB
Go

package fingerprint
import (
"fmt"
"net/http"
"net/url"
"os"
"regexp"
"strings"
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/awserr"
"github.com/aws/aws-sdk-go/aws/ec2metadata"
"github.com/aws/aws-sdk-go/aws/session"
log "github.com/hashicorp/go-hclog"
cleanhttp "github.com/hashicorp/go-cleanhttp"
"github.com/hashicorp/nomad/nomad/structs"
)
const (
// AwsMetadataTimeout is the timeout used when contacting the AWS metadata
// services.
AwsMetadataTimeout = 2 * time.Second
)
// map of instance type to approximate speed, in Mbits/s
// Estimates from http://stackoverflow.com/a/35806587
// This data is meant for a loose approximation
var ec2NetSpeedTable = map[*regexp.Regexp]int{
regexp.MustCompile("t2.nano"): 30,
regexp.MustCompile("t2.micro"): 70,
regexp.MustCompile("t2.small"): 125,
regexp.MustCompile("t2.medium"): 300,
regexp.MustCompile("m3.medium"): 400,
regexp.MustCompile("c4.8xlarge"): 4000,
regexp.MustCompile("x1.16xlarge"): 5000,
regexp.MustCompile(`.*\.large`): 500,
regexp.MustCompile(`.*\.xlarge`): 750,
regexp.MustCompile(`.*\.2xlarge`): 1000,
regexp.MustCompile(`.*\.4xlarge`): 2000,
regexp.MustCompile(`.*\.8xlarge`): 10000,
regexp.MustCompile(`.*\.10xlarge`): 10000,
regexp.MustCompile(`.*\.16xlarge`): 10000,
regexp.MustCompile(`.*\.32xlarge`): 10000,
}
// EnvAWSFingerprint is used to fingerprint AWS metadata
type EnvAWSFingerprint struct {
StaticFingerprinter
// endpoint for EC2 metadata as expected by AWS SDK
endpoint string
logger log.Logger
}
// NewEnvAWSFingerprint is used to create a fingerprint from AWS metadata
func NewEnvAWSFingerprint(logger log.Logger) Fingerprint {
f := &EnvAWSFingerprint{
logger: logger.Named("env_aws"),
endpoint: strings.TrimSuffix(os.Getenv("AWS_ENV_URL"), "/meta-data/"),
}
return f
}
func (f *EnvAWSFingerprint) Fingerprint(request *FingerprintRequest, response *FingerprintResponse) error {
cfg := request.Config
timeout := AwsMetadataTimeout
// Check if we should tighten the timeout
if cfg.ReadBoolDefault(TightenNetworkTimeoutsConfig, false) {
timeout = 1 * time.Millisecond
}
ec2meta, err := ec2MetaClient(f.endpoint, timeout)
if err != nil {
return fmt.Errorf("failed to setup ec2Metadata client: %v", err)
}
if !isAWS(ec2meta) {
return nil
}
// 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": false,
"hostname": true,
"instance-id": true,
"instance-type": false,
"local-hostname": true,
"local-ipv4": true,
"public-hostname": true,
"public-ipv4": true,
"mac": true,
"placement/availability-zone": false,
}
for k, unique := range keys {
resp, err := ec2meta.GetMetadata(k)
v := strings.TrimSpace(resp)
if v == "" {
f.logger.Debug("read an empty value", "attribute", k)
continue
} else if awsErr, ok := err.(awserr.RequestFailure); ok {
f.logger.Debug("could not read attribute value", "attribute", k, "error", awsErr)
continue
} else if awsErr, ok := err.(awserr.Error); ok {
// 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 := awsErr.OrigErr().(*url.Error); ok {
return nil
}
// not sure what other errors it would return
return err
}
// assume we want blank entries
key := "platform.aws." + strings.Replace(k, "/", ".", -1)
if unique {
key = structs.UniqueNamespace(key)
}
response.AddAttribute(key, v)
}
// accumulate resource information, then assign to response
var resources *structs.Resources
var nodeResources *structs.NodeResources
// copy over network specific information
if val, ok := response.Attributes["unique.platform.aws.local-ipv4"]; ok && val != "" {
response.AddAttribute("unique.network.ip-address", val)
nodeResources = new(structs.NodeResources)
nodeResources.Networks = []*structs.NetworkResource{
{
Mode: "host",
Device: "eth0",
IP: val,
CIDR: val + "/32",
MBits: f.throughput(request, ec2meta, val),
},
}
}
// copy over IPv6 network specific information
if val, ok := response.Attributes["unique.platform.aws.mac"]; ok && val != "" {
k := "network/interfaces/macs/" + val + "/ipv6s"
addrsStr, err := ec2meta.GetMetadata(k)
addrsStr = strings.TrimSpace(addrsStr)
if addrsStr == "" {
f.logger.Debug("read an empty value", "attribute", k)
} else if awsErr, ok := err.(awserr.RequestFailure); ok {
f.logger.Debug("could not read attribute value", "attribute", k, "error", awsErr)
} else if awsErr, ok := err.(awserr.Error); ok {
// 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 := awsErr.OrigErr().(*url.Error); ok {
return nil
}
// not sure what other errors it would return
return err
} else {
addrs := strings.SplitN(addrsStr, "\n", 2)
response.AddAttribute("unique.platform.aws.public-ipv6", addrs[0])
}
}
// copy over CPU speed information
if specs := f.lookupCPU(ec2meta); specs != nil {
response.AddAttribute("cpu.frequency", fmt.Sprintf("%d", specs.MHz))
response.AddAttribute("cpu.numcores", fmt.Sprintf("%d", specs.Cores))
f.logger.Debug("lookup ec2 cpu", "cores", specs.Cores, "ghz", log.Fmt("%.1f", specs.GHz()))
if ticks := specs.Ticks(); request.Config.CpuCompute <= 0 {
response.AddAttribute("cpu.totalcompute", fmt.Sprintf("%d", ticks))
f.logger.Debug("setting ec2 cpu", "ticks", ticks)
resources = new(structs.Resources)
resources.CPU = ticks
if nodeResources == nil {
nodeResources = new(structs.NodeResources)
}
nodeResources.Cpu = structs.NodeCpuResources{CpuShares: int64(ticks)}
} else {
response.AddAttribute("cpu.totalcompute", fmt.Sprintf("%d", request.Config.CpuCompute))
}
} else {
f.logger.Warn("failed to find the cpu specification for this instance type")
}
response.Resources = resources
response.NodeResources = nodeResources
// populate Links
response.AddLink("aws.ec2", fmt.Sprintf("%s.%s",
response.Attributes["platform.aws.placement.availability-zone"],
response.Attributes["unique.platform.aws.instance-id"]))
response.Detected = true
return nil
}
func (f *EnvAWSFingerprint) instanceType(ec2meta *ec2metadata.EC2Metadata) (string, error) {
response, err := ec2meta.GetMetadata("instance-type")
if err != nil {
return "", err
}
return strings.TrimSpace(response), nil
}
func (f *EnvAWSFingerprint) lookupCPU(ec2meta *ec2metadata.EC2Metadata) *CPU {
instanceType, err := f.instanceType(ec2meta)
if err != nil {
f.logger.Warn("failed to read EC2 metadata instance-type", "error", err)
return nil
}
return LookupEC2CPU(instanceType)
}
func (f *EnvAWSFingerprint) throughput(request *FingerprintRequest, ec2meta *ec2metadata.EC2Metadata, ip string) int {
throughput := request.Config.NetworkSpeed
if throughput != 0 {
return throughput
}
throughput = f.linkSpeed(ec2meta)
if throughput != 0 {
return throughput
}
if request.Node.Resources != nil && len(request.Node.Resources.Networks) > 0 {
for _, n := range request.Node.Resources.Networks {
if n.IP == ip {
return n.MBits
}
}
}
return defaultNetworkSpeed
}
// EnvAWSFingerprint uses lookup table to approximate network speeds
func (f *EnvAWSFingerprint) linkSpeed(ec2meta *ec2metadata.EC2Metadata) int {
instanceType, err := f.instanceType(ec2meta)
if err != nil {
f.logger.Error("error reading instance-type", "error", err)
return 0
}
netSpeed := 0
for reg, speed := range ec2NetSpeedTable {
if reg.MatchString(instanceType) {
netSpeed = speed
break
}
}
return netSpeed
}
func ec2MetaClient(endpoint string, timeout time.Duration) (*ec2metadata.EC2Metadata, error) {
client := &http.Client{
Timeout: timeout,
Transport: cleanhttp.DefaultTransport(),
}
c := aws.NewConfig().WithHTTPClient(client).WithMaxRetries(0)
if endpoint != "" {
c = c.WithEndpoint(endpoint)
}
sess, err := session.NewSession(c)
if err != nil {
return nil, err
}
return ec2metadata.New(sess, c), nil
}
func isAWS(ec2meta *ec2metadata.EC2Metadata) bool {
v, err := ec2meta.GetMetadata("ami-id")
v = strings.TrimSpace(v)
return err == nil && v != ""
}