python OPCUA or opcua-asyncio package installation failed in Linux ARM32V7

[rowshan]

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This is a BUG REPORT for issues in the existing code.

If you have general questions, code handling problems or ideas, please use the:

Discussionsboard: https://github.com/FreeOpcUa/opcua-asyncio/discussions
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---

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Describe the bug

I have opened the similar ticket for python-opcua.
I am advised to use the opcua-asyncio. but same problem i cannot make it work also for opcua-asyncio since I am trying to build the image in arm32v7 docker container. but i found the error in installing cryptography for opcua-asyncio development for arm32v7/python3.8 base image but it does not work .

To Reproduce

here is my docker file:
`FROM arm32v7/ubuntu:20.04
WORKDIR /sinewave
RUN apt-get update
&& DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends
software-properties-common
&& add-apt-repository -y ppa:deadsnakes
&& DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends
python3.8-venv
&& apt-get clean
&& rm -rf /var/lib/apt/lists/*
RUN python3.8 -m venv /venv
ENV PATH=/venv/bin:$PATH
#RUN apt-get install -y python3.8
RUN pip3 install asyncua

CMD [ "python3", "client.py" ]`

Screenshots

Version

Python-Version:

opcua-asyncio Version (e.g. master branch, 0.9):

[schroeder-]

This has nothing todo with your library, if you can't install a library please contact the library which is causing the error.

[rowshan]

Ok thanks. But here the problem is with opcua-asyncio package installation you can see in the error log:

here in order to work with opcua-asyncio I have to install asyncua package which is failing.

[oroulet]

looks like it is cryptograpjy package that has some issue on arm. That is strange.
Try installaing cryptography directly and tell us what is happening. if it fails you need to report the bug to the cryptography people

[oroulet]

also try installing cffi directly and let us know if it works

[rowshan]

Finally I made it work inside docker using arm32v7/debian base image. My Docker file is as follows:
###########
FROM arm32v7/debian:buster-slim
WORKDIR /sinewave
RUN apt-get update && apt-get install -y python3-pip python3-venv curl libxslt1.1
RUN pip3 install --upgrade pip
RUN curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain stable -y PATH="/root/.cargo/bin:${PATH}"
RUN
if [ dpkg --print-architecture = "armhf" ]; then
printf "[global]\nextra-index-url=https://www.piwheels.org/simple\n" > /etc/pip.conf ;
fi
RUN pip3 install cffi==1.13.1 cryptography==2.1.4
RUN python3 -m venv /venv
ENV PATH=/venv/bin:$PATH
ENV CRYPTOGRAPHY_DONT_BUILD_RUST=1
RUN pip3 install paramiko
RUN pip3 install asyncua
ENTRYPOINT [ "python3", "client.py" ]
#########
I had to downgrade libxslt to libxslt1.1 and cffi==1.13.1 cryptography==2.1.4 . it works for python-opcua as well as opcua-asyncio.
Thanks for your support. :)

[oroulet]

cryptography seems to be a at version 40 now and you had to set it version 2? that does not make sense. There is something wrong in your system

[rowshan]

Yes. Thanks. I tried with cryptography==37.0.3 and it worked. the main thing here is the wheels installation.
RUN if [ dpkg --print-architecture = "armhf" ]; then printf "[global]\nextra-index-url=[https://www.piwheels.org/simple\n](https://www.piwheels.org/simple%5Cn)" > /etc/pip.conf ; fi