packer-cn/builder/amazon/common/state.go

354 lines
11 KiB
Go

package common
import (
"log"
"os"
"strconv"
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/request"
"github.com/aws/aws-sdk-go/service/ec2"
"github.com/hashicorp/packer/helper/multistep"
)
// StateRefreshFunc is a function type used for StateChangeConf that is
// responsible for refreshing the item being watched for a state change.
//
// It returns three results. `result` is any object that will be returned
// as the final object after waiting for state change. This allows you to
// return the final updated object, for example an EC2 instance after refreshing
// it.
//
// `state` is the latest state of that object. And `err` is any error that
// may have happened while refreshing the state.
type StateRefreshFunc func() (result interface{}, state string, err error)
// StateChangeConf is the configuration struct used for `WaitForState`.
type StateChangeConf struct {
Pending []string
Refresh StateRefreshFunc
StepState multistep.StateBag
Target string
}
// Following are wrapper functions that use Packer's environment-variables to
// determing retry logic, then call the AWS SDK's built-in waiters.
func WaitUntilAMIAvailable(ctx aws.Context, conn *ec2.EC2, imageId string) error {
imageInput := ec2.DescribeImagesInput{
ImageIds: []*string{&imageId},
}
waitOpts := getWaiterOptions()
if len(waitOpts) == 0 {
// Bump this default to 30 minutes because the aws default
// of ten minutes doesn't work for some of our long-running copies.
waitOpts = append(waitOpts, request.WithWaiterMaxAttempts(120))
}
err := conn.WaitUntilImageAvailableWithContext(
ctx,
&imageInput,
waitOpts...)
return err
}
func WaitUntilInstanceTerminated(ctx aws.Context, conn *ec2.EC2, instanceId string) error {
instanceInput := ec2.DescribeInstancesInput{
InstanceIds: []*string{&instanceId},
}
err := conn.WaitUntilInstanceTerminatedWithContext(
ctx,
&instanceInput,
getWaiterOptions()...)
return err
}
// This function works for both requesting and cancelling spot instances.
func WaitUntilSpotRequestFulfilled(ctx aws.Context, conn *ec2.EC2, spotRequestId string) error {
spotRequestInput := ec2.DescribeSpotInstanceRequestsInput{
SpotInstanceRequestIds: []*string{&spotRequestId},
}
err := conn.WaitUntilSpotInstanceRequestFulfilledWithContext(
ctx,
&spotRequestInput,
getWaiterOptions()...)
return err
}
func WaitUntilVolumeAvailable(ctx aws.Context, conn *ec2.EC2, volumeId string) error {
volumeInput := ec2.DescribeVolumesInput{
VolumeIds: []*string{&volumeId},
}
err := conn.WaitUntilVolumeAvailableWithContext(
ctx,
&volumeInput,
getWaiterOptions()...)
return err
}
func WaitUntilSnapshotDone(ctx aws.Context, conn *ec2.EC2, snapshotID string) error {
snapInput := ec2.DescribeSnapshotsInput{
SnapshotIds: []*string{&snapshotID},
}
err := conn.WaitUntilSnapshotCompletedWithContext(
ctx,
&snapInput,
getWaiterOptions()...)
return err
}
// Wrappers for our custom AWS waiters
func WaitUntilVolumeAttached(ctx aws.Context, conn *ec2.EC2, volumeId string) error {
volumeInput := ec2.DescribeVolumesInput{
VolumeIds: []*string{&volumeId},
}
err := WaitForVolumeToBeAttached(conn,
ctx,
&volumeInput,
getWaiterOptions()...)
return err
}
func WaitUntilVolumeDetached(ctx aws.Context, conn *ec2.EC2, volumeId string) error {
volumeInput := ec2.DescribeVolumesInput{
VolumeIds: []*string{&volumeId},
}
err := WaitForVolumeToBeDetached(conn,
ctx,
&volumeInput,
getWaiterOptions()...)
return err
}
func WaitUntilImageImported(ctx aws.Context, conn *ec2.EC2, taskID string) error {
importInput := ec2.DescribeImportImageTasksInput{
ImportTaskIds: []*string{&taskID},
}
err := WaitForImageToBeImported(conn,
ctx,
&importInput,
getWaiterOptions()...)
return err
}
// Custom waiters using AWS's request.Waiter
func WaitForVolumeToBeAttached(c *ec2.EC2, ctx aws.Context, input *ec2.DescribeVolumesInput, opts ...request.WaiterOption) error {
w := request.Waiter{
Name: "DescribeVolumes",
MaxAttempts: 40,
Delay: request.ConstantWaiterDelay(5 * time.Second),
Acceptors: []request.WaiterAcceptor{
{
State: request.SuccessWaiterState,
Matcher: request.PathAllWaiterMatch,
Argument: "Volumes[].Attachments[].State",
Expected: "attached",
},
},
Logger: c.Config.Logger,
NewRequest: func(opts []request.Option) (*request.Request, error) {
var inCpy *ec2.DescribeVolumesInput
if input != nil {
tmp := *input
inCpy = &tmp
}
req, _ := c.DescribeVolumesRequest(inCpy)
req.SetContext(ctx)
req.ApplyOptions(opts...)
return req, nil
},
}
w.ApplyOptions(opts...)
return w.WaitWithContext(ctx)
}
func WaitForVolumeToBeDetached(c *ec2.EC2, ctx aws.Context, input *ec2.DescribeVolumesInput, opts ...request.WaiterOption) error {
w := request.Waiter{
Name: "DescribeVolumes",
MaxAttempts: 40,
Delay: request.ConstantWaiterDelay(5 * time.Second),
Acceptors: []request.WaiterAcceptor{
{
State: request.SuccessWaiterState,
Matcher: request.PathAllWaiterMatch,
Argument: "length(Volumes[].Attachments[]) == `0`",
Expected: true,
},
},
Logger: c.Config.Logger,
NewRequest: func(opts []request.Option) (*request.Request, error) {
var inCpy *ec2.DescribeVolumesInput
if input != nil {
tmp := *input
inCpy = &tmp
}
req, _ := c.DescribeVolumesRequest(inCpy)
req.SetContext(ctx)
req.ApplyOptions(opts...)
return req, nil
},
}
w.ApplyOptions(opts...)
return w.WaitWithContext(ctx)
}
func WaitForImageToBeImported(c *ec2.EC2, ctx aws.Context, input *ec2.DescribeImportImageTasksInput, opts ...request.WaiterOption) error {
w := request.Waiter{
Name: "DescribeImages",
MaxAttempts: 300,
Delay: request.ConstantWaiterDelay(5 * time.Second),
Acceptors: []request.WaiterAcceptor{
{
State: request.SuccessWaiterState,
Matcher: request.PathAllWaiterMatch,
Argument: "ImportImageTasks[].Status",
Expected: "completed",
},
{
State: request.FailureWaiterState,
Matcher: request.PathAnyWaiterMatch,
Argument: "ImportImageTasks[].Status",
Expected: "deleted",
},
},
Logger: c.Config.Logger,
NewRequest: func(opts []request.Option) (*request.Request, error) {
var inCpy *ec2.DescribeImportImageTasksInput
if input != nil {
tmp := *input
inCpy = &tmp
}
req, _ := c.DescribeImportImageTasksRequest(inCpy)
req.SetContext(ctx)
req.ApplyOptions(opts...)
return req, nil
},
}
w.ApplyOptions(opts...)
return w.WaitWithContext(ctx)
}
// This helper function uses the environment variables AWS_TIMEOUT_SECONDS and
// AWS_POLL_DELAY_SECONDS to generate waiter options that can be passed into any
// request.Waiter function. These options will control how many times the waiter
// will retry the request, as well as how long to wait between the retries.
// DEFAULTING BEHAVIOR:
// if AWS_POLL_DELAY_SECONDS is set but the others are not, Packer will set this
// poll delay and use the waiter-specific default
// if AWS_TIMEOUT_SECONDS is set but AWS_MAX_ATTEMPTS is not, Packer will use
// AWS_TIMEOUT_SECONDS and _either_ AWS_POLL_DELAY_SECONDS _or_ 2 if the user has not set AWS_POLL_DELAY_SECONDS, to determine a max number of attempts to make.
// if AWS_TIMEOUT_SECONDS, _and_ AWS_MAX_ATTEMPTS are both set,
// AWS_TIMEOUT_SECONDS will be ignored.
// if AWS_MAX_ATTEMPTS is set but AWS_POLL_DELAY_SECONDS is not, then we will
// use waiter-specific defaults.
type envInfo struct {
envKey string
Val int
overridden bool
}
type overridableWaitVars struct {
awsPollDelaySeconds envInfo
awsMaxAttempts envInfo
awsTimeoutSeconds envInfo
}
func getWaiterOptions() []request.WaiterOption {
envOverrides := getEnvOverrides()
waitOpts := applyEnvOverrides(envOverrides)
return waitOpts
}
func getOverride(varInfo envInfo) envInfo {
override := os.Getenv(varInfo.envKey)
if override != "" {
n, err := strconv.Atoi(override)
if err != nil {
log.Printf("Invalid %s '%s', using default", varInfo.envKey, override)
} else {
varInfo.overridden = true
varInfo.Val = n
}
}
return varInfo
}
func getEnvOverrides() overridableWaitVars {
// Load env vars from environment.
envValues := overridableWaitVars{
envInfo{"AWS_POLL_DELAY_SECONDS", 2, false},
envInfo{"AWS_MAX_ATTEMPTS", 0, false},
envInfo{"AWS_TIMEOUT_SECONDS", 0, false},
}
envValues.awsMaxAttempts = getOverride(envValues.awsMaxAttempts)
envValues.awsPollDelaySeconds = getOverride(envValues.awsPollDelaySeconds)
envValues.awsTimeoutSeconds = getOverride(envValues.awsTimeoutSeconds)
return envValues
}
func applyEnvOverrides(envOverrides overridableWaitVars) []request.WaiterOption {
waitOpts := make([]request.WaiterOption, 0)
// If user has set poll delay seconds, overwrite it. If user has NOT,
// default to a poll delay of 2 seconds
if envOverrides.awsPollDelaySeconds.overridden {
delaySeconds := request.ConstantWaiterDelay(time.Duration(envOverrides.awsPollDelaySeconds.Val) * time.Second)
waitOpts = append(waitOpts, request.WithWaiterDelay(delaySeconds))
}
// If user has set max attempts, overwrite it. If user hasn't set max
// attempts, default to whatever the waiter has set as a default.
if envOverrides.awsMaxAttempts.overridden {
waitOpts = append(waitOpts, request.WithWaiterMaxAttempts(envOverrides.awsMaxAttempts.Val))
}
if envOverrides.awsMaxAttempts.overridden && envOverrides.awsTimeoutSeconds.overridden {
log.Printf("WARNING: AWS_MAX_ATTEMPTS and AWS_TIMEOUT_SECONDS are" +
" both set. Packer will be using AWS_MAX_ATTEMPTS and discarding " +
"AWS_TIMEOUT_SECONDS. If you have not set AWS_POLL_DELAY_SECONDS, " +
"Packer will default to a 2 second poll delay.")
} else if envOverrides.awsTimeoutSeconds.overridden {
log.Printf("DEPRECATION WARNING: env var AWS_TIMEOUT_SECONDS is " +
"deprecated in favor of AWS_MAX_ATTEMPTS. If you have not " +
"explicitly set AWS_POLL_DELAY_SECONDS, we are defaulting to a " +
"poll delay of 2 seconds, regardless of the AWS waiter's default.")
maxAttempts := envOverrides.awsTimeoutSeconds.Val / envOverrides.awsPollDelaySeconds.Val
// override the delay so we can get the timeout right
if !envOverrides.awsPollDelaySeconds.overridden {
delaySeconds := request.ConstantWaiterDelay(time.Duration(envOverrides.awsPollDelaySeconds.Val) * time.Second)
waitOpts = append(waitOpts, request.WithWaiterDelay(delaySeconds))
}
waitOpts = append(waitOpts, request.WithWaiterMaxAttempts(maxAttempts))
}
if len(waitOpts) == 0 {
log.Printf("No AWS timeout and polling overrides have been set. " +
"Packer will default to waiter-specific delays and timeouts. If you would " +
"like to customize the length of time between retries and max " +
"number of retries you may do so by setting the environment " +
"variables AWS_POLL_DELAY_SECONDS and AWS_MAX_ATTEMPTS to your " +
"desired values.")
}
return waitOpts
}