[Mini-NDN] Beginners question: Mini-NDN applications & Python-NDN

Thu Aug 19 18:15:47 PDT 2021

Hi Peter,

Thank you very much for sharing your tips.  Your feedback can really help us improve Mini-NDN.  You can also directly contribute to the codebase (we have a list of open issues at https://redmine.named-data.net/projects/mini-ndn).

Lan

On Aug 13, 2021, at 2:50 AM, Peter Kietzmann <Peter.Kietzmann at haw-hamburg.de<mailto:Peter.Kietzmann at haw-hamburg.de>> wrote:

Hi Lan, Xinyu, all,

thanks for your responses. I got that running now, after going through a
bunch of beginners mistakes I made / had to deal with. Maybe it helps
someone:

- Calling python-ndn applications from mini-ndn led to some unresolved
dependencies. I worked around it by compiling executables from
producer/consumer examples (pyinstaller --onefile *.py) .
- From the new producer/consumer class in mini-ndn, execute the app
like: Application.start(self, <python executable>, self.logFile).
- I do not add FIB entries manually but utilize NLSR. To do so, I had to
change name prefixes of producer/consumer applications, e.g.,
/ndn/<node-site>/<node> .
- From mini-ndn, start producer first, to register prefix. Then, run
NLSR and give it a good amount of time (tens of seconds) before
requesting content on the consumer.

Cheers
Peter

On 13.08.21 04:58, Xinyu Ma wrote:
Hello, Peter,

Unfortunately, I have never used mini-NDN.
There are some python-ndn example applications under the examples
<https://github.com/named-data/python-ndn/tree/master/examples> folder,
but I don’t know how to run them on mini-NDN.
If you know how to execute python programs on mini-NDN, you can try to
run consumer.py and producer.py on two nodes, where the consumer’s node
has a FIB entry `/example` pointing to the producer’s node.

Best regards,
Xinyu Ma.

On Aug 12, 3 Reiwa, at 15:17, Lan Wang (lanwang) <lanwang at memphis.edu<mailto:lanwang at memphis.edu>
<mailto:lanwang at memphis.edu>> wrote:

I doubt people on the Mini-NDN mailing list know the answer.  It’s
best for Xinyu to help you.

Lan

On Jul 30, 2021, at 10:43 AM, Peter Kietzmann
<Peter.Kietzmann at haw-hamburg.de<mailto:Peter.Kietzmann at haw-hamburg.de>
<mailto:Peter.Kietzmann at haw-hamburg.de>> wrote:

Dear list, Lan, Xinyu Ma,

TL;DR:
does anyone have an example of how to run the python-NDN
producer/consumer example applications on multiple hosts started from
mini-NDN?

--

Many thanks for your guidance. I was able to move a bit forward (with
Philipps help), however, two questions remain open. Not sure which is
mini-NDN or python-NDN related.

Basically, I implement consumer/producer classes in
mini-NDN/examples/mnndn.py and start them separately (using AppManager)
on two different hosts in a three-node line topology. Internally, these
classes should call python-NDN/examples/consumer.py (and producer.py
respectively).

1. Calling the python script from the consumer class alike "python3
<path>/consumer.py" leads to:

"python3 /home/vagrant/python-ndn/examples/consumer.py" == Traceback
(most recent call last):
File "/home/vagrant/python-ndn/examples/consumer.py", line 19, in
<module>
  import ndn.utils
ModuleNotFoundError: No module named 'ndn'

This can be "fixed", creating a standalone executable from the
respective python script beforehand, but is very un-handy. What is a
better solution?

2. The current python-NDN producer is blocking. Where would be the right
place to make it asynchronous, within the python-NDN application, or
within mini-NDN that runs the application on a host?

Thanks again and cheers
Peter

On 29.07.21 18:30, Lan Wang (lanwang) wrote:
Hi Peter,

Welcome to Mini-NDN.  I think developing a Python-NDN application in
Mini-NDN is the same as developing it outside Mini-NDN.  The purpose of
using Mini-NDN is to avoid having to change any applications.  For
specific questions about Python NDN, it’s best to read the documentation
https://python-ndn.readthedocs.io/en/latest/src/examples/examples.html
and
ask the developers, e.g., Xinyu Ma (xinyu.ma at cs.ucla.edu
<mailto:xinyu.ma at cs.ucla.edu>
<mailto:xinyu.ma at cs.ucla.edu>).

Lan

On Jul 28, 2021, at 10:12 AM, Peter Kietzmann
<peter.kietzmann at haw-hamburg.de <mailto:peter.kietzmann at haw-hamburg.de>
<mailto:peter.kietzmann at haw-hamburg.de>> wrote:

CAUTION: This email originated from outside of the organization. Do
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and trust the content is safe.

Dear Community,

first of all: I am an absolute newbie to Mini-NDN (/the whole NDN code
base), so apologies for asking basic or duplicate questions :).

I've successfully installed your VM and played with built-in examples
(ndnping etc.) and my own topologies -> that worked well! Now I would
like to implement consumer/producer application logic. Python-NDN [1]
seems like a promising candidate, however, I cannot find starter
material. How to run Python-NDN applications on top of Mini-NDN?

Can anyone navigate me to a tutorial, a similar topic on this list, or
share first steps that might help to get started?

Many thanks in advance!

Cheers
Peter

[1] https://github.com/named-data/python-ndn

--
Peter Kietzmann

Hamburg University of Applied Sciences
Dept. Informatik, Internet Technologies Group
Berliner Tor 7, 20099 Hamburg, Germany
Fon: +49-40-42875-8426
Web: http://www.haw-hamburg.de/inet

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--
Peter Kietzmann

Hamburg University of Applied Sciences
Dept. Informatik, Internet Technologies Group
Berliner Tor 7, 20099 Hamburg, Germany
Fon: +49-40-42875-8426
Web: http://www.haw-hamburg.de/inet

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--
Peter Kietzmann

Hamburg University of Applied Sciences
Dept. Informatik, Internet Technologies Group
Berliner Tor 7, 20099 Hamburg, Germany
Fon: +49-40-42875-8426
Web: http://www.haw-hamburg.de/inet

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