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psycopg2:OperationalError: Unknow host in Python Tkinter app

Developing a desktop application with tkinter, I had an error connecting the database to it.
I'm new to this, I was working locally but I don't know what would happen if I want to share my app with other people. The app would not have access to this database.
I tried to create a database in render.com, once created I made the connection to it through psycopg2 passing the data (hostname, port, db_name, username, and password), but it throws me the error psycopg2:OperationalError.
I know that I am doing something wrong and I have been investigating but I have not been able to find the solution to this. So, when deploying a tkinter app, what database could it use? so that everyone can use the app correctly
I would appreciate any help you can give me, thanks in advance.
Here are the connection settings, which are the same settings from the database created on render.com (I've hidden the password and host):
conn = psycopg2.connect(
dbname='tkinter_app',
user='tkinter_app_user',
password='#############',
host='dpg-cfkimi9mbjsn9eclo3dg-a',
port='5432',
)
And here is the error log:
Traceback (most recent call last):
File "c:\Users\luigi\Desktop\Programacion\tkinter-postgresql-desktop\src\student.py", line 134, in <module>
display_students()
File "c:\Users\luigi\Desktop\Programacion\tkinter-postgresql-desktop\src\student.py", line 27, in display_students
conn = psycopg2.connect(
File "C:\Users\luigi\Desktop\Programacion\tkinter-postgresql-desktop\venv\lib\site-packages\psycopg2\__init__.py", line 122, in connect
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not translate host name "dpg-cfkimi9mbjsn9eclo3dg-a" to address: Unknown host
When I created the database, I copied all the configurations as they were, investigating I read that the host should be the External Database URL showed in the rander database configuration, but it didn't work either and it also throws me the error: Unknown Server error
I also try to connect the database in pgAdmin but throws me the same error Unknown host

smtplib times out connecting to AWS SES despite receiving a 220 service ready

I am attempting to send an email with AWS SES using a Dockerized Python program. When I try to connect to SES by making an SMTP instance, the program hangs and times out.
To reproduce:
Start the Python 3.6.8 REPL
Import smtplib
>>> import smtplib
Try to connect to SES, and observe how the statement hangs.
>>> conn = smtplib.SMTP(host='email-smtp.us-west-2.amazonaws.com', port=25)
# terminal hangs for 10 seconds
Try using the connection, which fails.
>>> conn.noop()
(451, b'4.4.2 Timeout waiting for data from client.')
>>> conn.noop()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib64/python3.6/smtplib.py", line 514, in noop
return self.docmd("noop")
File "/usr/lib64/python3.6/smtplib.py", line 421, in docmd
return self.getreply()
File "/usr/lib64/python3.6/smtplib.py", line 394, in getreply
raise SMTPServerDisconnected("Connection unexpectedly closed")
smtplib.SMTPServerDisconnected: Connection unexpectedly closed
Unsurprisingly, step (3) sends a DNS query for the SES endpoint, and then connects; the SES endpoint responds with 220 service ready nearly instantaneously. No traffic is exchanged until 10 seconds later, when SES closes the connection with 451 timeout waiting for client. The statement completes, and then runs the rest of my program which, of course, doesn't work.
For context, the rest of my script is as follows:
smtp_host = 'email-smtp.us-west-2.amazonaws.com'
smtp_port = 25
smtp_proto = 'tls'
with smtplib.SMTP(host=smtp_host, port=smtp_port) as connection:
try:
ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23 if smtp_proto == 'ssl' else ssl.PROTOCOL_TLS)
connection.starttls(context=ctx)
connection.ehlo()
connection.login(smtp_user, smtp_pass)
connection.send_message(from_addr=sender, to_addrs=recipients, msg=message)
except smtplib.SMTPHeloError as e:
print(f"SMTP HELO Failed: {e}")
except smtplib.SMTPAuthenticationError as e:
print(f"SMTP AUTH Failed: {e}")
except smtplib.SMTPException as e:
print(f"Failed to send email: {e}")
I've attempted to connect on ports 25, 587, 2587, and 465. I've done the same with the SMTP_SSL object instead, as well as changing the context in the starttls call to various SSL / TLS versions (the SSL versions result in this error - but this isn't relevant since I can't get to this portion of the script, anyway).
I've tested my connection to SES according to this article. I've also tried parts of this and this SO post (as well as a myriad of others that are lost in my browser history).
To actually send emails, I need to connect a second time. Connecting, then waiting for a timeout, then connecting again, seems wrong. What is the proper way to do this?

SMTP_HELO returns timeout when running email address validation

Using library py3-validate-email-1.0.5 (more here) to check if email address is valid, including SMTP check, I wasn't able to make it through check_smtp step, because I get following error:
Python script
from validate_email import validate_email
from validate_email import validate_email_or_fail
from csv import DictReader
# iterate over each line by column name
with open('email-list.csv', 'r') as read_obj:
csv_dict_reader = DictReader(read_obj, delimiter=';')
for row in csv_dict_reader:
i = 1
while i < 21:
header_name = 'Email'+str(i)
if validate_email_or_fail(
email_address=row[header_name],
check_format=True,
check_blacklist=True,
check_dns=True,
dns_timeout=10,
check_smtp=True,
smtp_timeout=5,
smtp_helo_host='emailsrv.domain.com',
smtp_from_address='email#domain.com',
smtp_skip_tls=False,
smtp_tls_context=None,
smtp_debug=False):
print('Email ' + row[header_name] + ' is valid.')
else:
print('Email ' + row[header_name] + ' is invalid.')
i += 1
Error:
Traceback (most recent call last):
File "//./main.py", line 13, in <module>
if validate_email_or_fail(
File "/usr/local/lib/python3.9/site-packages/validate_email/validate_email.py", line 59, in validate_email_or_fail
return smtp_check(
File "/usr/local/lib/python3.9/site-packages/validate_email/smtp_check.py", line 229, in smtp_check
return smtp_checker.check(hosts=mx_records)
File "/usr/local/lib/python3.9/site-packages/validate_email/smtp_check.py", line 197, in check
raise SMTPTemporaryError(error_messages=self.__temporary_errors)
validate_email.exceptions.SMTPTemporaryError: Temporary error in email address verification:
mx.server.com: 451 timed out (in reply to 'connect')
I figured there is problem with my DNS settings (probably), so I dockerized the script and run it on AWS EC2, where I have used elastic IP, attached it to the EC2 instance where docker container is running, I also setup reverse DNS for domain emailsrv.domain.com with this elastic IP. Tried to run the script, no change.
Then I added MX record pointing to the emailsrv.domain.com, but still no change. The DNS records are setup properly, because I have checked it with multiple DNS tools available.
Since the library doesn't require to actually use my email address login details, I wonder what can be the problem? Just to be sure, the email address used in the script doesn't exist, since I don't have smtp server setup on that instance, obviously.
Any ideas?

Reason behind this was closed port on AWS EC2 instance. Opening the port in security group is not enough, you must send a request to AWS so they remove the restriction on port 25.
When they did that, works flawlessly.

Connection to remote mysql server through ssh using python mysqldb connector passwordless

Python 3.8
Mysql 8.0.23-0ubuntu0.20.04.1 for Linux on x86_64 ((Ubuntu))
Hi,
I want to connect to a distant mysql server using python's mysqldb connector and paramiko's sshtunnelforwarder.
I can connect to the database remotely without any problems by executing the following:
Connecting to database using mysql password authentication
server = new_ssh_server(config)
with server:
print('Connection', server.local_bind_address)
cnx = MySQLdb.connect(host = '127.0.0.1',
port = server.local_bind_port,
user = config['user'],
passwd = config['password'],
db = config['db'])
Queries work, I can read/write to database, no problem.
I would like to connect to database without supplying mysql password, by using mysql auth_socket authentication method, through ssh.
My attempts at this can be resumed by the following code:
Connecting to database using mysql auth_socket authentication
with server as tunnel:
print('Tunnel:', tunnel.local_bind_address)
cnx = MySQLdb.connect(host = 'localhost', user = 'hillbilly', password = '', db='tutut')#, unix_socket="/tmp/mysql.sock")
res = pd.read_sql('select * from users;', cnx)
print(res)
Which throws the following error:
File "connect_ssh_mysql_auth_socket.py", line 12, in <module>
cnx = MySQLdb.connect(host = 'localhost', user = 'hillbilly', password = '', db='rsotest2')#, unix_socket="/tmp/mysql.sock")
File "...../lib/python3.8/site-packages/MySQLdb/__init__.py", line 84, in Connect
return Connection(*args, **kwargs)
File "...../lib/python3.8/site-packages/MySQLdb/connections.py", line 179, in __init__
super(Connection, self).__init__(*args, **kwargs2)
MySQLdb._exceptions.OperationalError: (2002, "Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)")
I have and existing mysqld.sock on the distant server that I symlinked to /tmp/mysql.sock, but the error remains. I have also added the next line to /etc/mysql/mysql.conf.d/mysql.cnf:
socket=/run/mysqld/mysqld.sock
But I still get the same error when trying to connect remotely.
Specifying the unix_socket='/run/mysqld/mysqld.sock' to mysqldb connector (commented in Connecting to database using mysql auth_socket authentication) does not fix the issue.
I seem to misunderstand the use of mysql.sock, mysqld.sock.
I was not able to find nor create a mysql.sock socket.
Is what I am trying to do possible? I remember reading somewhere that unix sockets only work locally, does this mean it is not achievable?
Any help/explanation would be appreciated.
(EDIT AND CLOSING)
So this is not possible. Following this thread, auth_socket needs local access to the socket file (usually /tmp/mysql.sock) to run autentication tests, so not accessible through ssh tunneling.

Authentication to remote mysql server using auth_socket plugin is not possible through sshtunnel, as the plugin requires local access to the socket file. See this thread for more information.

can't login with Paramiko ssh client

local-host --->Aterm server (security server ) -----> target-machine(
I am trying to write a code in Python using Paramiko to first SSH from local-host to the target-machine. From the target-machine, I want to capture some outputs and store them locally either as a variable or as a file (havent got to that point yet). I found an example from stackoverflow where they talk about using nested SSH with paramiko, and I follow it but I get stuck here:
i need just reaching the target-machine
My code:
import paramiko
import sys
import subprocess
hostname = '10.10.10.1'
port = 22
username = 'mohamed.hosseny'
password ='Pass#1'
client = paramiko.Transport((hostname, port))
client.connect(username=username, password=password)
client.close()
but i found the below error message :
Traceback (most recent call last):
File "C:/Users/mohamed.hosseny/Desktop/Paramiko.py", line 13, in <module>
client = paramiko.Transport((hostname, port))
File "C:\Python27\lib\site-packages\paramiko\transport.py", line 332, in
__init__
'Unable to connect to {}: {}'.format(hostname, reason))
SSHException: Unable to connect to 10.10.10.1: [Errno 10060] A connection
attempt failed because the connected party did not properly respond after
a period of time, or established connection failed because connected host
has failed to respond

paramiko.Transport is a lower level API. Don't use it unless you have a good reason. Instead, you can use paramiko.SSHClient.