How to get rid of cryptography build error?

Question

I am trying to build a dockerfile but the problem is when it trying to build specifically cryptography is not building.

MY Dockerfile

FROM python:3.7-alpine  ENV PYTHONUNBUFFERED 1  RUN apk update \   # psycopg2 dependencies   && apk add --virtual build-deps gcc python3-dev musl-dev\   && apk add postgresql-dev \   && apk add build-base \   # Pillow dependencies   && apk add jpeg-dev zlib-dev freetype-dev lcms2-dev openjpeg-dev tiff-dev tk-dev tcl-dev \   # CFFI dependencies   && apk add libffi-dev py-cffi \   # Translations dependencies   && apk add gettext \   # https://docs.djangoproject.com/en/dev/ref/django-admin/#dbshell   && apk add postgresql-client \   # cairo   && apk add cairo cairo-dev pango-dev gdk-pixbuf-dev poppler-utils  # fonts for weasyprint RUN mkdir ~/.fonts COPY ./fonts/* /root/.fonts/  # secret key (should be in docker-secrets, or we need to run minikube locally RUN mkdir /etc/secrets COPY secret.readme proxy_rsa_key* /etc/secrets/  # Requirements are installed here to ensure they will be cached. COPY ./requirements /requirements RUN pip install -r /requirements/local.txt  COPY ./compose/local/django/entrypoint /entrypoint RUN sed -i 's/\r//' /entrypoint RUN chmod +x /entrypoint  COPY ./compose/local/django/start /start RUN sed -i 's/\r//' /start RUN chmod +x /start  COPY ./compose/local/django/celery/worker/start /start-celeryworker RUN sed -i 's/\r//' /start-celeryworker RUN chmod +x /start-celeryworker  COPY ./compose/local/django/celery/beat/start /start-celerybeat RUN sed -i 's/\r//' /start-celerybeat RUN chmod +x /start-celerybeat  COPY ./compose/local/django/celery/flower/start /start-flower RUN sed -i 's/\r//' /start-flower RUN chmod +x /start-flower  WORKDIR /app  ENTRYPOINT ["/entrypoint"] 

when I try to build my dockerfile it shows:

Building wheel for cryptography (PEP 517): finished with status 'error'   ERROR: Command errored out with exit status 1:      error: Can not find Rust compiler   ----------------------------------------   ERROR: Failed building wheel for cryptography  

I tried to solve but i couldn't. I am newbie in docker.Please help how to get rid of this problem.

Answer 1

cryptography < 3.5:

You can skip the rust installation and other related dependencies by adding the line below before apk add commands:

ENV CRYPTOGRAPHY_DONT_BUILD_RUST=1 

cryptography >= 3.5: Thanks @riptusk331

After this version rust will be required. Either install a specific version <3.5 or follow cryptography installation instructions. It is stated in the attached link that they are very aggressively explained in the docs.

Answer 2

Since the error is...

error: Can not find Rust compiler 

...the solution is to install the rust compiler. You'll also need cargo, the Rust package manager, and it looks like your Dockerfile is missing openssl-dev.

The following builds successfully for me:

FROM python:3.7-alpine  ENV PYTHONUNBUFFERED 1  RUN apk add --update \   build-base \   cairo \   cairo-dev \   cargo \   freetype-dev \   gcc \   gdk-pixbuf-dev \   gettext \   jpeg-dev \   lcms2-dev \   libffi-dev \   musl-dev \   openjpeg-dev \   openssl-dev \   pango-dev \   poppler-utils \   postgresql-client \   postgresql-dev \   py-cffi \   python3-dev \   rust \   tcl-dev \   tiff-dev \   tk-dev \   zlib-dev  RUN pip install cryptography 

Note that the above apk add ... command line is largely the same as what you've got; I've just simplified the multiple apk add ... statements into a single apk add execution.