traefik/provider/ecs.go
Vincent Demeester 3f293ee25b Move docker provider to its own package 👼
Makes it simpler to manage :)

Signed-off-by: Vincent Demeester <vincent@sbr.pm>
2017-04-17 15:40:55 +02:00

473 lines
13 KiB
Go

package provider
import (
"context"
"fmt"
"strconv"
"strings"
"text/template"
"time"
"github.com/BurntSushi/ty/fun"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/defaults"
"github.com/aws/aws-sdk-go/aws/ec2metadata"
"github.com/aws/aws-sdk-go/aws/request"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/ec2"
"github.com/aws/aws-sdk-go/service/ecs"
"github.com/cenk/backoff"
"github.com/containous/traefik/job"
"github.com/containous/traefik/log"
"github.com/containous/traefik/safe"
"github.com/containous/traefik/types"
)
var _ Provider = (*ECS)(nil)
// ECS holds configurations of the ECS provider.
type ECS struct {
BaseProvider `mapstructure:",squash"`
Domain string `description:"Default domain used"`
ExposedByDefault bool `description:"Expose containers by default"`
RefreshSeconds int `description:"Polling interval (in seconds)"`
// ECS lookup parameters
Cluster string `description:"ECS Cluster Name"`
Region string `description:"The AWS region to use for requests"`
AccessKeyID string `description:"The AWS credentials access key to use for making requests"`
SecretAccessKey string `description:"The AWS credentials access key to use for making requests"`
}
type ecsInstance struct {
Name string
ID string
task *ecs.Task
taskDefinition *ecs.TaskDefinition
container *ecs.Container
containerDefinition *ecs.ContainerDefinition
machine *ec2.Instance
}
type awsClient struct {
ecs *ecs.ECS
ec2 *ec2.EC2
}
func (provider *ECS) createClient() (*awsClient, error) {
sess := session.New()
ec2meta := ec2metadata.New(sess)
if provider.Region == "" {
log.Infoln("No EC2 region provided, querying instance metadata endpoint...")
identity, err := ec2meta.GetInstanceIdentityDocument()
if err != nil {
return nil, err
}
provider.Region = identity.Region
}
cfg := &aws.Config{
Region: &provider.Region,
Credentials: credentials.NewChainCredentials(
[]credentials.Provider{
&credentials.StaticProvider{
Value: credentials.Value{
AccessKeyID: provider.AccessKeyID,
SecretAccessKey: provider.SecretAccessKey,
},
},
&credentials.EnvProvider{},
&credentials.SharedCredentialsProvider{},
defaults.RemoteCredProvider(*(defaults.Config()), defaults.Handlers()),
}),
}
return &awsClient{
ecs.New(sess, cfg),
ec2.New(sess, cfg),
}, nil
}
// Provide allows the provider to provide configurations to traefik
// using the given configuration channel.
func (provider *ECS) Provide(configurationChan chan<- types.ConfigMessage, pool *safe.Pool, constraints types.Constraints) error {
provider.Constraints = append(provider.Constraints, constraints...)
handleCanceled := func(ctx context.Context, err error) error {
if ctx.Err() == context.Canceled || err == context.Canceled {
return nil
}
return err
}
pool.Go(func(stop chan bool) {
ctx, cancel := context.WithCancel(context.Background())
go func() {
select {
case <-stop:
cancel()
}
}()
operation := func() error {
aws, err := provider.createClient()
if err != nil {
return err
}
configuration, err := provider.loadECSConfig(ctx, aws)
if err != nil {
return handleCanceled(ctx, err)
}
configurationChan <- types.ConfigMessage{
ProviderName: "ecs",
Configuration: configuration,
}
if provider.Watch {
reload := time.NewTicker(time.Second * time.Duration(provider.RefreshSeconds))
defer reload.Stop()
for {
select {
case <-reload.C:
configuration, err := provider.loadECSConfig(ctx, aws)
if err != nil {
return handleCanceled(ctx, err)
}
configurationChan <- types.ConfigMessage{
ProviderName: "ecs",
Configuration: configuration,
}
case <-ctx.Done():
return handleCanceled(ctx, ctx.Err())
}
}
}
return nil
}
notify := func(err error, time time.Duration) {
log.Errorf("ECS connection error %+v, retrying in %s", err, time)
}
err := backoff.RetryNotify(safe.OperationWithRecover(operation), job.NewBackOff(backoff.NewExponentialBackOff()), notify)
if err != nil {
log.Errorf("Cannot connect to ECS api %+v", err)
}
})
return nil
}
func wrapAws(ctx context.Context, req *request.Request) error {
req.HTTPRequest = req.HTTPRequest.WithContext(ctx)
return req.Send()
}
func (provider *ECS) loadECSConfig(ctx context.Context, client *awsClient) (*types.Configuration, error) {
var ecsFuncMap = template.FuncMap{
"filterFrontends": provider.filterFrontends,
"getFrontendRule": provider.getFrontendRule,
}
instances, err := provider.listInstances(ctx, client)
if err != nil {
return nil, err
}
instances = fun.Filter(provider.filterInstance, instances).([]ecsInstance)
return provider.GetConfiguration("templates/ecs.tmpl", ecsFuncMap, struct {
Instances []ecsInstance
}{
instances,
})
}
// Find all running ECS tasks in a cluster, also collect the task definitions (for docker labels)
// and the EC2 instance data
func (provider *ECS) listInstances(ctx context.Context, client *awsClient) ([]ecsInstance, error) {
var taskArns []*string
req, _ := client.ecs.ListTasksRequest(&ecs.ListTasksInput{
Cluster: &provider.Cluster,
DesiredStatus: aws.String(ecs.DesiredStatusRunning),
})
for ; req != nil; req = req.NextPage() {
if err := wrapAws(ctx, req); err != nil {
return nil, err
}
taskArns = append(taskArns, req.Data.(*ecs.ListTasksOutput).TaskArns...)
}
// Early return: if we can't list tasks we have nothing to
// describe below - likely empty cluster/permissions are bad. This
// stops the AWS API from returning a 401 when you DescribeTasks
// with no input.
if len(taskArns) == 0 {
return []ecsInstance{}, nil
}
chunkedTaskArns := provider.chunkedTaskArns(taskArns)
var tasks []*ecs.Task
for _, arns := range chunkedTaskArns {
req, taskResp := client.ecs.DescribeTasksRequest(&ecs.DescribeTasksInput{
Tasks: arns,
Cluster: &provider.Cluster,
})
if err := wrapAws(ctx, req); err != nil {
return nil, err
}
tasks = append(tasks, taskResp.Tasks...)
}
containerInstanceArns := make([]*string, 0)
byContainerInstance := make(map[string]int)
taskDefinitionArns := make([]*string, 0)
byTaskDefinition := make(map[string]int)
for _, task := range tasks {
if _, found := byContainerInstance[*task.ContainerInstanceArn]; !found {
byContainerInstance[*task.ContainerInstanceArn] = len(containerInstanceArns)
containerInstanceArns = append(containerInstanceArns, task.ContainerInstanceArn)
}
if _, found := byTaskDefinition[*task.TaskDefinitionArn]; !found {
byTaskDefinition[*task.TaskDefinitionArn] = len(taskDefinitionArns)
taskDefinitionArns = append(taskDefinitionArns, task.TaskDefinitionArn)
}
}
machines, err := provider.lookupEc2Instances(ctx, client, containerInstanceArns)
if err != nil {
return nil, err
}
taskDefinitions, err := provider.lookupTaskDefinitions(ctx, client, taskDefinitionArns)
if err != nil {
return nil, err
}
var instances []ecsInstance
for _, task := range tasks {
machineIdx := byContainerInstance[*task.ContainerInstanceArn]
taskDefIdx := byTaskDefinition[*task.TaskDefinitionArn]
for _, container := range task.Containers {
taskDefinition := taskDefinitions[taskDefIdx]
var containerDefinition *ecs.ContainerDefinition
for _, def := range taskDefinition.ContainerDefinitions {
if *container.Name == *def.Name {
containerDefinition = def
break
}
}
instances = append(instances, ecsInstance{
fmt.Sprintf("%s-%s", strings.Replace(*task.Group, ":", "-", 1), *container.Name),
(*task.TaskArn)[len(*task.TaskArn)-12:],
task,
taskDefinition,
container,
containerDefinition,
machines[machineIdx],
})
}
}
return instances, nil
}
func (provider *ECS) lookupEc2Instances(ctx context.Context, client *awsClient, containerArns []*string) ([]*ec2.Instance, error) {
order := make(map[string]int)
instanceIds := make([]*string, len(containerArns))
instances := make([]*ec2.Instance, len(containerArns))
for i, arn := range containerArns {
order[*arn] = i
}
req, _ := client.ecs.DescribeContainerInstancesRequest(&ecs.DescribeContainerInstancesInput{
ContainerInstances: containerArns,
Cluster: &provider.Cluster,
})
for ; req != nil; req = req.NextPage() {
if err := wrapAws(ctx, req); err != nil {
return nil, err
}
containerResp := req.Data.(*ecs.DescribeContainerInstancesOutput)
for i, container := range containerResp.ContainerInstances {
order[*container.Ec2InstanceId] = order[*container.ContainerInstanceArn]
instanceIds[i] = container.Ec2InstanceId
}
}
req, _ = client.ec2.DescribeInstancesRequest(&ec2.DescribeInstancesInput{
InstanceIds: instanceIds,
})
for ; req != nil; req = req.NextPage() {
if err := wrapAws(ctx, req); err != nil {
return nil, err
}
instancesResp := req.Data.(*ec2.DescribeInstancesOutput)
for _, r := range instancesResp.Reservations {
for _, i := range r.Instances {
if i.InstanceId != nil {
instances[order[*i.InstanceId]] = i
}
}
}
}
return instances, nil
}
func (provider *ECS) lookupTaskDefinitions(ctx context.Context, client *awsClient, taskDefArns []*string) ([]*ecs.TaskDefinition, error) {
taskDefinitions := make([]*ecs.TaskDefinition, len(taskDefArns))
for i, arn := range taskDefArns {
req, resp := client.ecs.DescribeTaskDefinitionRequest(&ecs.DescribeTaskDefinitionInput{
TaskDefinition: arn,
})
if err := wrapAws(ctx, req); err != nil {
return nil, err
}
taskDefinitions[i] = resp.TaskDefinition
}
return taskDefinitions, nil
}
func (i ecsInstance) label(k string) string {
if v, found := i.containerDefinition.DockerLabels[k]; found {
return *v
}
return ""
}
func (provider *ECS) filterInstance(i ecsInstance) bool {
if len(i.container.NetworkBindings) == 0 {
log.Debugf("Filtering ecs instance without port %s (%s)", i.Name, i.ID)
return false
}
if i.machine == nil ||
i.machine.State == nil ||
i.machine.State.Name == nil {
log.Debugf("Filtering ecs instance in an missing ec2 information %s (%s)", i.Name, i.ID)
return false
}
if *i.machine.State.Name != ec2.InstanceStateNameRunning {
log.Debugf("Filtering ecs instance in an incorrect state %s (%s) (state = %s)", i.Name, i.ID, *i.machine.State.Name)
return false
}
if i.machine.PrivateIpAddress == nil {
log.Debugf("Filtering ecs instance without an ip address %s (%s)", i.Name, i.ID)
return false
}
label := i.label("traefik.enable")
enabled := provider.ExposedByDefault && label != "false" || label == "true"
if !enabled {
log.Debugf("Filtering disabled ecs instance %s (%s) (traefik.enabled = '%s')", i.Name, i.ID, label)
return false
}
return true
}
func (provider *ECS) filterFrontends(instances []ecsInstance) []ecsInstance {
byName := make(map[string]bool)
return fun.Filter(func(i ecsInstance) bool {
if _, found := byName[i.Name]; !found {
byName[i.Name] = true
return true
}
return false
}, instances).([]ecsInstance)
}
func (provider *ECS) getFrontendRule(i ecsInstance) string {
if label := i.label("traefik.frontend.rule"); label != "" {
return label
}
return "Host:" + strings.ToLower(strings.Replace(i.Name, "_", "-", -1)) + "." + provider.Domain
}
// ECS expects no more than 100 parameters be passed to a DescribeTask call; thus, pack
// each string into an array capped at 100 elements
func (provider *ECS) chunkedTaskArns(tasks []*string) [][]*string {
var chunkedTasks [][]*string
for i := 0; i < len(tasks); i += 100 {
sliceEnd := -1
if i+100 < len(tasks) {
sliceEnd = i + 100
} else {
sliceEnd = len(tasks)
}
chunkedTasks = append(chunkedTasks, tasks[i:sliceEnd])
}
return chunkedTasks
}
func (i ecsInstance) Protocol() string {
if label := i.label("traefik.protocol"); label != "" {
return label
}
return "http"
}
func (i ecsInstance) Host() string {
return *i.machine.PrivateIpAddress
}
func (i ecsInstance) Port() string {
return strconv.FormatInt(*i.container.NetworkBindings[0].HostPort, 10)
}
func (i ecsInstance) Weight() string {
if label := i.label("traefik.weight"); label != "" {
return label
}
return "0"
}
func (i ecsInstance) PassHostHeader() string {
if label := i.label("traefik.frontend.passHostHeader"); label != "" {
return label
}
return "true"
}
func (i ecsInstance) Priority() string {
if label := i.label("traefik.frontend.priority"); label != "" {
return label
}
return "0"
}
func (i ecsInstance) EntryPoints() []string {
if label := i.label("traefik.frontend.entryPoints"); label != "" {
return strings.Split(label, ",")
}
return []string{}
}