Help requested to run the pre keyword server

[lionel-wilhelm]

🔍 Before submitting the issue

• I have searched among the existing issues
• I am using a Python virtual environment

🐞 Description of the bug

Following the instructions here https://github.com/ansys/pydyna/blob/main/src/ansys/dyna/core/pre/README.md, I can't manage to start the kwserver.

I'm running Jupyterlab in a Docker image (on the cloud) and I have a module creating geometries in python. I would like to automate the creation of lsdyna input files so that they can then be transferred to an other machine with a proper lsdyna installation and solver.

As far as I understand, my Jupyter instance doesn't need to access any ansys license server to create my input k-file. Is this correct ?

As I'm already running in a docker container, I don't want to run the server in a separate docker instance.

It seems that there is something wrong with the keywordreader python package as I get the following error message when I try to start the keyword server (python kwserver.py) :

Traceback (most recent call last):
  File "/home/container_user/workspace/pydyna/pydyna-venv/share/linux-binaries/kwserver.py", line 25, in <module>
    from keywordreader import KeywordReader as kp
SystemError: initialization of keywordreader raised unreported exception

I tried few things to figure out what was wrong but none of them was successful.

Running Ubuntu 22.04.5 LTS and Python 3.11.11.

Any help would be greatly appreciated. Thanks in advance

📝 Steps to reproduce

# Step 1: Create and activate a Python virtual environment
python -m venv pydyna-venv
source ./pydyna-venv/bin/activate

# Step 2: Clone the pydyna repository from GitHub
git clone https://github.com/pyansys/pydyna.git
cd pydyna

# Step 3: Install the dependencies from the setup.py
pip install .  # Mostly to install dependencies

# Step 4: Change to the docker/pre directory
cd docker/pre

# Step 5: Download the linux-binaries.zip from the release
wget https://github.com/ansys/pydyna/releases/download/v0.4.6/linux-binaries.zip

# Step 6: Unzip the downloaded file and remove the zip file
unzip -uq linux-binaries.zip && rm linux-binaries.zip

# Step 7: Install necessary Python packages for gRPC and protobuf
pip install grpcio grpcio-tools protobuf

# Step 8: Generate Python code from the kwprocess.proto file using gRPC tools
python -m grpc_tools.protoc --python_out=./linux-binaries --grpc_python_out=./linux-binaries -I./linux-binaries ./linux-binaries/kwprocess.proto

# Step 9: Create required directories and move files to the correct location
mkdir --parents linux-binaries/lib/linux; mv linux-binaries/keywordreader.so $_

# Step 10: Make sure that the library is available in the python path
cp linux-binaries/lib/linux/keywordreader.so ../../../pydyna-venv/lib/python3.11/site-packages/

# Step 11: Run the kwserver.py script to start the server
python linux-binaries/kwserver.py

💻 Which operating system are you using?

Linux

📀 Which ANSYS version are you using?

No response

🐍 Which Python version are you using?

3.11

📦 Installed packages

ansys-api-dyna==0.4.2
ansys-dpf-core==0.13.4
ansys-dyna-core @ file:///home/container_user/workspace/pydyna
ansys-tools-path==0.7.1
appdirs==1.4.4
cachetools==5.5.1
certifi==2025.1.31
charset-normalizer==3.4.1
click==8.1.8
contourpy==1.3.1
cycler==0.12.1
fonttools==4.56.0
google-api-core==2.24.1
google-api-python-client==2.160.0
google-auth==2.38.0
google-auth-httplib2==0.2.0
googleapis-common-protos==1.66.0
grpcio==1.70.0
grpcio-tools==1.70.0
hollerith==0.6.0
httplib2==0.22.0
idna==3.10
importlib_metadata==8.6.1
kiwisolver==1.4.8
matplotlib==3.10.0
numpy==2.2.2
packaging==24.2
pandas==2.2.3
pillow==11.1.0
platformdirs==4.3.6
pooch==1.8.2
proto-plus==1.26.0
protobuf==5.29.3
psutil==6.1.1
pyasn1==0.6.1
pyasn1_modules==0.4.1
pyparsing==3.2.1
python-dateutil==2.9.0.post0
pytz==2025.1
pyvista==0.44.2
requests==2.32.3
rsa==4.9
scooby==0.10.0
six==1.17.0
tqdm==4.67.1
typing_extensions==4.12.2
tzdata==2025.1
uritemplate==4.1.1
urllib3==2.3.0
vtk==9.3.1
zipp==3.21.0

[koubaa]

If you want an API directly to create keywords, consider using the "keywords" subpackage, rather than "pre". "keywords" does not require a container or a server.

[lionel-wilhelm]

Thanks a lot @koubaa for the answer. I will use the keywords sub-package for the keywords. Regarding the initial issue, I would have several questions :

1. It seems that the default linux-binaries for the pre server were released on version 0.4.8 (e.g. the ones that are automatically downloaded : https://github.com/ansys/pydyna/blob/main/src/ansys/dyna/core/pre/launcher.py#L115). But more recent assets were also released for version 0.5.0 (https://github.com/ansys/pydyna/releases/download/v0.5.0/ansys-pydyna-server.zip). Could you please provide guidance on which one to use for the latest pydyna release (0.7.0) `
2. Could you please provide some details about the environment used to compile keywordreader.so linux binary ?

Finally, could you please explain what the pre keyword server provides as additional features with respect to the keywords
sub-package ? In which situation should the pre server be favoured with respect to the keywords sub-package ?

Thanks in advance, with best regards,

[koubaa]

@lionel-wilhelm

The keywords subpackage lets you directly manipulate keywords and their fields. It is pure python, has no need for a license, and does not require any server running.

The pre subpackage gives a higher level interface that hides the complexity of keywords. It requires a license and running a server.

I am only responsible for the keywords and run subpackages, I'm not knowledgeable enough about the pre subpackage to help with this problem.

paging @kanthadya in case you decide to move forward with the pre subpackage

[lionel-wilhelm]

Hi @koubaa,
Thanks for the clarification about pre and keywords packages. Regarding the pre server, it seems the documentation states :

3.1 Getting started
To use the solver features of PyDYNA, you must have a valid LS-DYNA license.
For information on getting a licensed copy of LS-DYNA, see the Ansys LS-DYNA page on the Ansys website.

but doesn't mention the pre package or the kwServer. My cloud instance doesn't have access to my ansys license server (because it isn't exposed on the public internet) so if the pre package requires a license, I will have to work with the keywords module.

In addition to this, when setting up the gRPC service exposing the compiled keywordsreader library, no licensing information is required. I would be very interested to work with the pre subpackage as this would lead to a more generic, maintainable and elegant solution.

Looking forward to @kanthadya 's info/comments about this.

[koubaa]

@lionel-wilhelm In hindsight I may be wrong about the licensing part.

[kanthadya]

@zhangzhanqun , can you please comment on this installation? The pre module doesn’t need any license checkouts

[lionel-wilhelm]

hi @zhangzhanqun ,
Do you have any hint which could help me overcome the above issue ?
Thanks in advance

[lionel-wilhelm]

Any news on this one ?

[kanthadya]

Pre server by itself doesn’t need any license. But having said that , I think keywords module also allows you the same ease of use. You can write utilities that does multiple keyword setup automatically and repeatedly and make it more elegant. Pre was designed mostly for complete LSDYNA novice . I’d recommend you to use keywords module. If you need more clarification please leave your email and I’ll get in touch with you.

[lionel-wilhelm]

I already used the keywords package for a specific project and wanted to explore more generic way to create lsdyna input files with python.
I'd be glad to pursue the conversion by email lionel.wilhelm (at) neuralconcept.com.
Thanks in advance.