To check whether AWS instance is up after reboot using python

问题

Is there a way to check if an AWS instance has finally come up in python either using boto3 or otherwise. The running state doesnt differentiate between rebooting and finally up phase.

回答1:

If you just want to check that a remote port is open you could use the built-in socket package.

Here's a quick modification of this answer of waiting for a remote port to open:

import socket
import time

def wait_for_socket(host, port, retries, retry_delay=30):
    retry_count = 0
    while retry_count <= retries:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        result = sock.connect_ex((host, port))
        sock.close()
        if result == 0:
            print "Port is open"
            break
        else:
            print "Port is not open, retrying..."
            time.sleep(retry_delay)

回答2:

All the info is available inside boto3 documentation http://boto3.readthedocs.org/en/latest/reference/services/ec2.html

This will show all the information of the instances.

import boto3
reservations = boto3.client("ec2").describe_instances()["Reservations"]
for reservation in reservations:
  for each in reservation["Instances"]:
    print " instance-id{} :  {}".format(each["InstanceId"], each["State"]["Name"])

# or use describe_instance_status, much simpler query
instances = boto3.client("ec2").describe_instance_status()
for each in instances["InstanceStatuses"]: 
  print " instance-id{} :  {}".format(each["InstanceId"], each["InstanceState"]["Name"])

From the documentation :

State (dict) --

The current state of the instance.

Code (integer) --

The low byte represents the state. The high byte is an opaque internal value and should be ignored.

0 : pending
16 : running
32 : shutting-down
48 : terminated
64 : stopping
80 : stopped
Name (string) --

The current state of the instance.

In fact, there is no code state show "rebooting" inside the documentation. I can't really test it out on my own EC2 instances , because after I do reboot, it seems the instances reboot so fast that AWS console doesn't have a chance to show a "Rebooting" state.

Nevertheless, http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/monitoring-system-instance-status-check.html

The following are examples of problems that can cause instance status checks to fail:

Failed system status checks

Incorrect networking or startup configuration

Exhausted memory

Corrupted file system

Incompatible kernel

回答3:

You could also use the InstanceStatusOk waiter in boto3 or whatever waiter is approprate.

import boto3

instance_id = '0-12345abcde'

client = boto3.client('ec2')
client.reboot_instances(InstanceIds=[instance_id])

waiter = client.get_waiter('instance_status_ok')
waiter.wait(InstanceIds=[instance_id])

print("The instance now has a status of 'ok'!")

来源：https://stackoverflow.com/questions/36590699/to-check-whether-aws-instance-is-up-after-reboot-using-python

标签

python

python-3.x

amazon-web-services

boto3

aws-ec2