如何在EC2启动实例请求中获取公共IP地址？

Question

我无法弄明白我该怎么做:

runInstancesRequest.withImageId("ami-53170b32")
                .withInstanceType("t2.micro")
                .withMinCount(1)
                .withMaxCount(1)
                .withKeyName("mac")
                .withSecurityGroupIds("sg-49025d2d");

RunInstancesResult runInstancesResult =
                amazonEC2Client.runInstances(runInstancesRequest);

到目前为止一切正常.现在我想从最近启动的实例中获取公共IP地址.我怎样才能做到这一点？

我试过了:

runInstancesResult.getReservation().getInstances().get(0).getPublicIpAddress()

但IP始终为空.

Answer 1

启动实例时,它进入Pending状态并且还没有公共IP地址.您需要等待一段时间才能使用它.

几秒钟后,DescribeInstances使用最初返回的Instance ID 调用,然后解压缩PublicIpAddress.

这是从AWS命令行界面(CLI)执行的转储:

$ aws ec2 run-instances --image-id ami-1500742f ...
{
    "OwnerId": "123456789012", 
    "ReservationId": "r-0d8cc4a12a94faba7", 
    "Groups": [], 
    "Instances": [
        {
            "Monitoring": {
                "State": "disabled"
            }, 
            "PublicDnsName": "", 
            "KernelId": "aki-c362fff9", 
            "State": {
                "Code": 0, 
                "Name": "pending"
            }, 
            "EbsOptimized": false, 
            "LaunchTime": "2016-01-22T21:17:49.000Z", 
            "PrivateIpAddress": "172.31.12.208", 
            "ProductCodes": [], 
            "VpcId": "vpc-7d087014", 
            "StateTransitionReason": "", 
            "InstanceId": "i-0afe19e0d061b95b5", 
...
}

$ aws ec2 describe-instances --instance-ids i-0afe19e0d061b95b5
{
    "Reservations": [
        {
            "OwnerId": "123456789012", 
            "ReservationId": "r-0d8cc4a12a94faba7", 
            "Groups": [], 
            "Instances": [
                {
                    "Monitoring": {
                        "State": "disabled"
                    }, 
                    "PublicDnsName": "ec2-52-62-35-146.ap-southeast-2.compute.amazonaws.com", 
                    "RootDeviceType": "ebs", 
                    "State": {
                        "Code": 16, 
                        "Name": "running"
                    }, 
                    "EbsOptimized": false, 
                    "LaunchTime": "2016-01-22T21:17:49.000Z", 
                    "PublicIpAddress": "52.62.35.146", 
                    "PrivateIpAddress": "172.31.12.208", 
...
}