Setting Up Fabric SSH, Error:Timed Out - ssh

Question

I'm new to Fabric, so this might have a simple answer I've missed due to bad search terminology.
I'm trying to start a new ubuntu EC2 instance in AWS, then connect to it with Fabric and have it execute several commands. However, it seems there is a problem with Fabric's SSH connection, maybe I'm defining some env variable wrong?
#task //starts new EC2 instance and sets env variables
def prep_deploy():
//code to start new EC2 instance, named buildhost
env.hosts=[buildhost.public_dns_name]
env.user = "ubuntu"
env.key_filename = ".../keypair.pem"
env.port = 22
#task
def deploy():
run("echo $HOME") //code fails here
....
I run fab prep_deploy deploy, since I read you need a new task for the new env variables to take effect.
I get
Fatal error: Timed out trying to connect to ...amazonaws.com (tried 1 time)
Underlying exception: timed out
The security groups for the instance are open to SSH: I can connect through Putty. In fact, if I empty the `env.host_string' variable at the start of deploy(), when it prompts me to manually input a host, I can write in "ubuntu#...amazonaws.com:22", with the host name exactly as seen from output at the task start, and it will connect to the instance. But I can't figure how to manipulate the environment variables so that it understands the host name.

Answer 1

It looks like your fabric settings are correct with the use of variables. I was able to use the code you provided to connect to my Ubuntu VM. I am wondering if you are having a connection issue due to the amazon Instance not being fully booted and ready for connections when your script runs the second task. I have run into that issue on a different VM hosts.
I added the following code to check and try the connection again. This might help you
import socket
import time
def waitforssh():
s=socket.socket()
address=env.host_string
port=22
while True:
time.sleep(5)
try:
s.connect((address,port))
return
except Exception,e:
print "failed to connec to %s:%s %(address,port)
pass
insert the function call into your deploy task
def deploy():
waitforssh()
This should test the connection. If the port does not respond, it will wait 5 seconds and try again.
That could explain why your second attempt to connect works.