Add creation of the conda-ci-linux-64 container (conda#10795)

* Add creation of the conda-ci-linux-64 container

The logic moved from https://github.com/ContinuumIO/docker-images

While the Dockerfile is untouched, the github action was updated to use
a build matrix, to publish to ghcr.io and to specify the Python version in
the image tag instead of the image name.

* Adapt to review findings

* Add Dockerfile linting with hadolint

.github/workflows/ci_image.yml

@@ -0,0 +1,37 @@
+name: Build and Publish Conda CI Images
+on:
+  schedule:
+    - cron:  '0 0 * * 0'
+  pull_request:
+    paths:
+      - 'ci/Dockerfile'
+      - '.github/workflows/ci_image.yml'
+  push:
+    paths:
+      - 'ci/Dockerfile'
+      - '.github/workflows/ci_image.yml'
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python: [3.7, 3.8, 3.9]
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: lint
+        uses: hadolint/[email protected]
+        with:
+          dockerfile: ./ci/Dockerfile
+
+      - name: build-push conda-ci-linux-64-python-${{ matrix.python }}
+        uses: docker/build-push-action@v2
+        with:
+          context: ./ci
+          file: ./ci/Dockerfile
+          build-args: PYTHON_VERSION=${{ matrix.python }}
+          tags: conda/conda-ci-linux-64:python${{ matrix.python }}-latest
+          push: ${{ github.ref == 'refs/heads/master' }}
+

ci/Dockerfile

@@ -0,0 +1,43 @@
+FROM debian:buster-slim
+
+ENV LANG=C.UTF-8 LC_ALL=C.UTF-8
+ENV PATH /opt/conda/bin:$PATH
+
+# hadolint ignore=DL3008
+RUN apt-get update --fix-missing && \
+    apt-get install -y --no-install-recommends tini wget build-essential bzip2 ca-certificates libglib2.0-0 libxext6 libsm6 libxrender1 git mercurial subversion sudo && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/* && \
+    useradd -m -s /bin/bash test_user && \
+    usermod -u 1001 test_user && \
+    groupmod -g 1001 test_user && \
+    echo "test_user ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers && \
+    wget --quiet https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh -O ~/miniconda.sh && \
+    /bin/bash ~/miniconda.sh -b -p /opt/conda && \
+    rm ~/miniconda.sh && \
+    /opt/conda/bin/conda clean --all --yes
+
+ARG PYTHON_VERSION=3.8
+
+# conda and test dependencies
+RUN /opt/conda/bin/conda install --update-all -y -c defaults \
+    conda conda-package-handling \
+    python=$PYTHON_VERSION pip pycosat requests ruamel_yaml cytoolz \
+    anaconda-client nbformat make \
+    pytest pytest-cov codecov radon pytest-timeout mock responses pexpect \
+    flake8 && \
+    /opt/conda/bin/conda clean --all --yes
+
+# conda-build and test dependencies
+RUN /opt/conda/bin/conda install --update-all -y -c defaults \
+        conda-build patch git \
+        perl pytest-xdist pytest-mock \
+        anaconda-client \
+        filelock jinja2 conda-verify pkginfo \
+        glob2 beautifulsoup4 chardet pycrypto \
+    && /opt/conda/bin/conda clean --all --yes
+
+USER test_user
+
+ENTRYPOINT ["/usr/bin/tini", "--"]
+CMD ["/bin/bash"]