func getInstancesWithTag(ec2Client *ec2.EC2, key string, value string) ([]*ec2.Instance, error) {
var instances []*ec2.Instance
err := ec2Client.DescribeInstancesPages(&ec2.DescribeInstancesInput{
Filters: []*ec2.Filter{
&ec2.Filter{
Name: aws.String("instance-state-name"),
Values: []*string{aws.String("running")},
},
&ec2.Filter{
Name: aws.String(fmt.Sprintf("tag:%s", key)),
Values: []*string{aws.String(value)},
},
},
}, func(result *ec2.DescribeInstancesOutput, _ bool) bool {
for _, reservation := range result.Reservations {
instances = append(instances, reservation.Instances...)
}
return true // keep going
})
if err != nil {
return nil, err
}
return instances, nil
}
func processInstances(svc *ec2.EC2, pageSize *int64, apply func([]*string)) {
err := svc.DescribeInstancesPages(&ec2.DescribeInstancesInput{
MaxResults: pageSize,
},
func(instancesOut *ec2.DescribeInstancesOutput, lastPage bool) bool {
var instanceIds []*string
for idx := range instancesOut.Reservations {
for _, instance := range instancesOut.Reservations[idx].Instances {
instanceIds = append(instanceIds, instance.InstanceId)
}
}
apply(instanceIds)
return !lastPage
})
kingpin.FatalIfError(err, "Could not retrieve EC2 instances")
}