yml and sphinx to build an empty rtd website

.gitlab-ci.yml

-image: python:3.9-slim-buster
-pages:
-  stage: deploy
+stages:
+  # --- Docker build stage ---
+  # The first stage contains jobs used to build
+  # docker images 'ready to use' for build/install.
+  # Requirement for jobs in this stage :
+  # - should build and push a docker image to siconos project registry
+  # - should be allowed to failed (in order to avoid blocking of last stage jobs)
+  # - should run only when commit message contains [docker build]
+  # - use Dockerfile from ci_gitlab/dockerfiles/<image-name>
+  #
+  - docker-build
+  # --- Doc stages ---
+  # Build documentation (run doxygen, sphinx, ...)
+  - doc-build
+  # Publish html pages
+  - doc-deploy 
+
+
+ubuntu20.4-doc:docker-build:
+  variables:
+    IMAGE_NAME: ubuntu20.04-doc
+  image:
+    name: gcr.io/kaniko-project/executor:debug
+    entrypoint: [""]
+  variables:
+    GIT_STRATEGY: clone
+  stage: docker-build
+  script:
+    - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
+    - sed -i "s|REGISTRY_PATH|$CI_PROJECT_PATH|g" $CI_PROJECT_DIR/ci/Dockerfile
+    - /kaniko/executor --context $CI_PROJECT_DIR --dockerfile ci/Dockerfile --destination $CI_REGISTRY_IMAGE/$IMAGE_NAME:latest
+  rules:
+   - if: $CI_COMMIT_MESSAGE =~ /^\[docker-build\]/
+     when: always
+   - when: never
 
+# --- Build doc/web site and publish it ---
+doc:build:
+  variables:
+    IMAGE_NAME: $CI_REGISTRY_IMAGE/ubuntu20.04-doc
   script:
-    - pip install -U sphinx
-    - pip install sphinx_rtd_theme
-    - pip install recommonmark
-    - sphinx-build -d _public/doctrees docs/ _build/html
-    - mv _build/html/* public
+    - sphinx-build -b html -d build/doctrees docs/ build
+  artifacts:
+    paths:
+      - build/
+pages:
 
+  image: python:alpine
+  script:
+  - mv build  public
   artifacts:
     paths:
     - public
-  rules:
-    - if: $CI_COMMIT_REF_NAME == $CI_DEFAULT_BRANCH
+  stage: doc-deploy 
+  needs: ["doc:build"]

ci/Dockerfile

+FROM ubuntu:20.04
+ENV TZ=Europe/Paris
+RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone && apt update  && apt install -y -qq \
+        ntp \
+        git-core \
+        make \
+        vim \
+        libpython3-dev \
+        python3 \
+        python3-pip \
+        python3-packaging \
+        graphviz doxygen texlive-latex-base && apt autoclean -y && apt autoremove -y&& rm -rf /var/lib/apt/lists/*
+WORKDIR /home
+COPY requirements4doc.txt /home
+RUN pip3 install -U -r /home/requirements4doc.txt

ci/requirements4doc.txt

+sphinx-rtd-theme
+sphinxcontrib-bibtex
+sphinxcontrib-websupport
+sphinx-rtd-theme
+
+

docs/conf.py

+# Configuration file for the Sphinx documentation builder.
+#
+# This file only contains a selection of the most common options. For a full
+# list see the documentation:
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
+
+# -- Path setup --------------------------------------------------------------
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+# import os
+# import sys
+# sys.path.insert(0, os.path.abspath('.'))
+
+
+# -- Project information -----------------------------------------------------
+
+project = 'hysop'
+copyright = '2021, hysop team'
+author = 'hysop team'
+
+# The full version, including alpha/beta/rc tags
+release = '1.0.0'
+
+
+# -- General configuration ---------------------------------------------------
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+]
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This pattern also affects html_static_path and html_extra_path.
+exclude_patterns = []
+
+
+# -- Options for HTML output -------------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+html_theme = 'alabaster'
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
\ No newline at end of file

docs/index.rst

+.. hysop documentation master file, created by
+   sphinx-quickstart on Thu Nov  4 13:58:20 2021.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Welcome to hysop's documentation!
+=================================
+
+.. toctree::
+   :maxdepth: 2
+   :caption: Contents:
+
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`