Python traceback and attribute errors for AWS and Boto3 - python-3.x

Question

Working on getting this script running on Python 3 from earlier version 2 and still getting some traceback and Attribute errors. Below is the error and below that the script in its current state: Special thanks for #Madlania Kalunder for sorting the printing issues. Now I know things are close but need some help.
Traceback (most recent call last):
File "ec2-instances.py", line 97, in <module> sys.exit(main())
File "ec2-instances.py", line 78, in main hosts=(list_instances)(filter)
File "ec2-instances.py", line 18, in list_instances
name = (item for item in i.tags if item ["Key"] == "Name" ).next()
AttributeError: 'generator' object has no attribute 'next'
Below is the code. Sorry for formatting issues here and thanks in advance for the help.
#!/usr/bin/env python
import boto3
import sys
import argparse
import paramiko
def list_instances(Filter):
ec2 = boto3.resource('ec2')
instances = ec2.instances.filter(Filters=Filter)
(columns_format) = ("%-3s %-26s %-16s %-16s %-20s %-12s %-12s %-16s")
print ((columns_format) % ("num", "Name", "Public IP", "Private IP", "ID", "Type", "VPC", "Status"))
num = 1
hosts = []
name = {}
for i in instances:
try:
name = (item for item in i.tags if item ["Key"] == "Name" ).next()
except StopIteration:
name['Value'] = ''
print (columns_format) % (
num,
name['Value'],
i.public_ip_address,
i.private_ip_address,
i.id,
i.instance_type,
i.vpc_id,
i.state['Name']
)
num = num + 1
item={'id': i.id, 'ip': i.public_ip_address, 'hostname': name ['Value'], 'status': i.state['Name'],}
hosts.append(item)
return hosts
def execute_cmd(host,user,cmd):
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
try:
ssh.connect(host, username=user)
stdin, stdout, stderr = ssh.exec_command(cmd)
stdout=stdout.read()
stderr=stderr.read()
ssh.close()
return stdout,stderr
except paramiko.AuthenticationException as exception:
return "Authentication Error trying to connect into the host %s with the user %s. Plese review your keys" % (host, user), e
def main():
parser = argparse.ArgumentParser()
parser.add_argument('-n', '--name',
help="Filter result by name.")
parser.add_argument('-t', '--type',
help="Filer result by type.")
parser.add_argument('-s', '--status',
help="Filter result by status." )
parser.add_argument('-e', '--execute',
help="Execute a command on instances")
parser.add_argument('-u', '--user', default="ubuntu",
help="User to run commands if -e option is used.\
Ubuntu user is used by default")
arg = parser.parse_args()
# Default filter if no options are specified
filter=[]
if arg.name:
filter.append({'Name': 'tag-value', 'Values': ["*" + arg.name + "*"]})
if arg.type:
filter.append({'Name': 'instance-type', 'Values': ["*" + arg.type + "*"]})
if arg.status:
filter.append({'Name': 'instance-state-name', 'Values': ["*" + arg.status + "*"]})
hosts=list_instances(filter)
names = ""
if arg.execute:
for item in hosts:
names = names + " " + item["hostname"] + "(" + item["id"] + ")"
print ("\nCommand to execute: %s") % arg.execute
print ("Executed by: %s") % arg.user
print ("Hosts list: %s\n") % names
for item in hosts:
if item["status"] == 'running':
print ("::: %s (%s)") % (item["hostname"], item["id"])
stdout,stderr = execute_cmd(item["ip"], arg.user, arg.execute)
print (stdout)
print (stderr)
else:
print ("::: %s (%s) is not running (command execution skiped)") % (item["hostname"], item["id"])
if __name__ == '__main__':
sys.exit(main())

Answer 1

Got some help from a colleague and here is the now correct/working version. More print issues needed fixing with () to include the % and removing the specific exception rule. Also corrected the .next to include the generator.
#!/usr/bin/env python
import boto3
import sys
import argparse
import paramiko
def list_instances(Filter):
ec2 = boto3.resource('ec2')
instances = ec2.instances.filter(Filters=Filter)
(columns_format) = ("%-3s %-26s %-16s %-16s %-20s %-12s %-12s %-16s")
print ((columns_format) % ("num", "Name", "Public IP", "Private IP", "ID", "Type", "VPC", "Status"))
num = 1
hosts = []
name = {}
for i in instances:
try:
name = next(item for item in i.tags if item["Key"] == "Name")
except:
name['Value'] = ''
print ((columns_format) % (
num,
name['Value'],
i.public_ip_address,
i.private_ip_address,
i.id,
i.instance_type,
i.vpc_id,
i.state['Name']
))
num = num + 1
item={'id': i.id, 'ip': i.public_ip_address, 'hostname': name ['Value'], 'status': i.state['Name'],}
hosts.append(item)
return hosts
def execute_cmd(host,user,cmd):
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
try:
ssh.connect(host, username=user)
stdin, stdout, stderr = ssh.exec_command(cmd)
stdout=stdout.read()
stderr=stderr.read()
ssh.close()
return stdout,stderr
except paramiko.AuthenticationException as exception:
return "Authentication Error trying to connect into the host %s with the user %s. Plese review your keys" % (host, user), e
def main():
parser = argparse.ArgumentParser()
parser.add_argument('-n', '--name',
help="Filter result by name.")
parser.add_argument('-t', '--type',
help="Filer result by type.")
parser.add_argument('-s', '--status',
help="Filter result by status." )
parser.add_argument('-e', '--execute',
help="Execute a command on instances")
parser.add_argument('-u', '--user', default="ubuntu",
help="User to run commands if -e option is used.\
Ubuntu user is used by default")
arg = parser.parse_args()
# Default filter if no options are specified
filter=[]
if arg.name:
filter.append({'Name': 'tag-value', 'Values': ["*" + arg.name + "*"]})
if arg.type:
filter.append({'Name': 'instance-type', 'Values': ["*" + arg.type + "*"]})
if arg.status:
filter.append({'Name': 'instance-state-name', 'Values': ["*" + arg.status + "*"]})
hosts=list_instances(filter)
names = ""
if arg.execute:
for item in hosts:
names = names + " " + item["hostname"] + "(" + item["id"] + ")"
print (("\nCommand to execute: %s") % arg.execute)
print (("Executed by: %s") % arg.user)
print (("Hosts list: %s\n") % names)
for item in hosts:
if item["status"] == 'running':
print (("::: %s (%s)") % (item["hostname"], item["id"]))
stdout,stderr = execute_cmd(item["ip"], arg.user, arg.execute)
print (stdout)
print (stderr)
else:
print (("::: %s (%s) is not running (command execution skiped)") % (item["hostname"], item["id"]))
if __name__ == '__main__':
sys.exit(main())