Rootless docker causes "failed to resolve address for github.com" - linux

Question

In my dockerfile i'm installing cryptography python dependency however when building wheel from rootless docker i'm getting following error:
...
generating cffi module 'build/temp.linux-x86_64-3.7/_openssl.c'
running build_rust
Updating crates.io index
warning: spurious network error (2 tries remaining): failed to resolve address for github.com: Name does not resolve; class=Net (12)
warning: spurious network error (1 tries remaining): failed to resolve address for github.com: Name does not resolve; class=Net (12)
error: failed to get `pyo3` as a dependency of package `cryptography-rust v0.1.0 (/tmp/pip-install-h22hlaqn/cryptography_a2037904c10949639ccf8a3b2519f187/src/rust)`
Caused by:
failed to fetch `https://github.com/rust-lang/crates.io-index`
Caused by:
network failure seems to have happened
if a proxy or similar is necessary `net.git-fetch-with-cli` may help here
https://doc.rust-lang.org/cargo/reference/config.html#netgit-fetch-with-cli
Caused by:
failed to resolve address for github.com: Name does not resolve; class=Net (12)
=============================DEBUG ASSISTANCE=============================
If you are seeing a compilation error please try the following steps to
successfully install cryptography:
1) Upgrade to the latest pip and try again. This will fix errors for most
users. See: https://pip.pypa.io/en/stable/installing/#upgrading-pip
2) Read https://cryptography.io/en/latest/installation.html for specific
instructions for your platform.
3) Check our frequently asked questions for more information:
https://cryptography.io/en/latest/faq.html
4) Ensure you have a recent Rust toolchain installed:
https://cryptography.io/en/latest/installation.html#rust
5) If you are experiencing issues with Rust for *this release only* you may
set the environment variable `CRYPTOGRAPHY_DONT_BUILD_RUST=1`.
=============================DEBUG ASSISTANCE=============================
...
The strangest thing that the same dockerfile compiles absolutely successfully when built from root user.
I'm using the most recent docker version on arch linux and have tried following instructions here: https://docs.docker.com/engine/security/rootless/ and installing AUR and in both cases had no luck.
That's my docker file:
FROM python:3.7-alpine
ENV LANG C.UTF-8
RUN apk update \
&& apk add --virtual build-deps gcc g++ musl-dev python3 python3-dev autoconf automake linux-headers make libffi-dev openssl-dev \
&& apk add --no-cache bash postgresql-dev libxml2-dev libxslt-dev jpeg-dev zlib-dev freetype-dev lcms2-dev openjpeg-dev tiff-dev tk-dev tcl-dev git openssh-client rust cargo
RUN mkdir -p /opt/carryall/app
RUN mkdir -p /opt/carryall/static
RUN mkdir -p /opt/carryall/media
WORKDIR /opt/carryall/app
RUN mkdir /root/.ssh/
ADD id_rsa /root/.ssh/id_rsa_temp
RUN cat /root/.ssh/id_rsa_temp | tr -d '\r' > /root/.ssh/id_rsa
RUN chmod 400 /root/.ssh/id_rsa
RUN touch /root/.ssh/known_hosts
RUN ssh-keyscan bitbucket.org >> /root/.ssh/known_hosts
ADD requirements.txt /opt/carryall/app/
RUN pip install --no-cache-dir -r /opt/carryall/app/requirements.txt
RUN apk del --purge build-deps \
&& rm -rf /root/.cache /tmp/*
ADD . /opt/carryall/app