Docs tutorial: Network - TCP sockets(Star Wars Asciimation)

[keithostertag]

Not sure where to post this?

I am following the tutorial
https://docs.micropython.org/en/latest/ ... k_tcp.html

Section 5.1 has a tutorial showing how to connect to the Star Wars Asciimation at towel.blinkenlights.nl

Even though the tutorial appears under the ESP8266 section, I am testing this from my desktop computer running Linux. Here's what I get when I follow the given steps:

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keith@ada:~$ python
Python 3.9.2 (default, Feb 28 2021, 17:03:44) 
[GCC 10.2.1 20210110] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import socket
>>> addr_info = socket.getaddrinfo("towel.blinkenlights.nl", 23)
>>> addr = addr_info[0][-1]
>>> s = socket.socket()
>>> s.connect(addr)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: AF_INET address must be a pair (host, port)

>>> 

I then tried this to see what I could see:

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>>> addr
('2001:7b8:666:ffff::1:42', 23, 0, 0)
>>> addr_info
[(<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('2001:7b8:666:ffff::1:42', 23, 0, 0)), (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('2001:7b8:666:ffff::1:42', 23, 0, 0)), (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_RAW: 3>, 0, '', ('2001:7b8:666:ffff::1:42', 23, 0, 0)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('213.136.8.188', 23)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('213.136.8.188', 23)), (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_RAW: 3>, 0, '', ('213.136.8.188', 23))]
>>> addr_info[0][-1]
('2001:7b8:666:ffff::1:42', 23, 0, 0)
>>> addr_info[-1][-1]
('213.136.8.188', 23)

Well, that looks more like the (host, port), so I then changed the statement

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addr = addr_info[0][-1]

to this:

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addr = addr_info[-1][-1]

and while I no longer get the error I also do not get connected (timed out). I can telnet directly from the command line with no issues. Am I making a mistake, or does the Doc need editing, or perhaps both?

[karfas]

>>>

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>>> addr_info
[ (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('2001:7b8:666:ffff::1:42', 23, 0, 0)), 
  (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('2001:7b8:666:ffff::1:42', 23, 0, 0)), 
  (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_RAW: 3>, 0, '', ('2001:7b8:666:ffff::1:42', 23, 0, 0)), 
  (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('213.136.8.188', 23)), 
  (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('213.136.8.188', 23)), 
  (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_RAW: 3>, 0, '', ('213.136.8.188', 23))
]

As stated in the fine documentation, getaddrinfo returns an array.

I reformatted the addr_info you get. The socket() call in the tutorial uses addrinfo[0][-1]. This is in your case an IPv6 address.
Unless your network can handle IPV6, you should filter the returned array for AF_INET/SOCK_STREAM.
For a quick test, you could use socket.connect(addrinfo[3][-1]).

EDIT: I see you already tried this. Maybe your network doesn't route your device to external or your device isn't connected ?