Telemetry: track Sphinx extensions and html_theme variables

[humitos]

Pretty simple implementation to track Sphinx's extensions and theme. This is not the best implementation, but I think it could be good as a first start.

The new doctool key added will have this shape:

  "doctool": {
    "extensions": [
      "readthedocs_ext.readthedocs",
      "notfound.extension",
      "autoapi.extension",
      "sphinx_tabs.tabs",
      "sphinx-prompt",
      "sphinxemoji.sphinxemoji"
    ],
    "name": "sphinx",
    "theme": "sphinx_rtd_theme"
  },

Closes #9627
Requires: readthedocs/readthedocs-sphinx-ext#117

---

📚 Documentation previews 📚

• User's documentation (docs): https://docs--9639.org.readthedocs.build/en/9639/

• Developer's documentation (dev): https://dev--9639.org.readthedocs.build/en/9639/

[humitos]

This is how it looks the output now that we are using app.extensions. Note that it considers all the extensions, including the default ones:

 "doctool": {
    "extensions": [
      "sphinx.ext.mathjax",
      "sphinx.builders.html",
      "sphinx.builders.applehelp",
      "sphinx.builders.changes",
      "sphinx.builders.epub3",
      "sphinx.builders.devhelp",
      "sphinx.builders.dummy",
      "sphinx.builders.gettext",
      "sphinx.builders.htmlhelp",
      "sphinx.builders.latex",
      "sphinx.builders.linkcheck",
      "sphinx.builders.manpage",
      "sphinx.builders.qthelp",
      "sphinx.builders.texinfo",
      "sphinx.builders.text",
      "sphinx.builders.websupport",
      "sphinx.builders.xml",
      "sphinx.config",
      "sphinx.domains.c",
      "sphinx.domains.changeset",
      "sphinx.domains.cpp",
      "sphinx.domains.javascript",
      "sphinx.domains.math",
      "sphinx.domains.python",
      "sphinx.domains.rst",
      "sphinx.domains.std",
      "sphinx.directives",
      "sphinx.directives.code",
      "sphinx.directives.other",
      "sphinx.directives.patches",
      "sphinx.extension",
      "sphinx.io",
      "sphinx.parsers",
      "sphinx.registry",
      "sphinx.roles",
      "sphinx.transforms.post_transforms",
      "sphinx.transforms.post_transforms.code",
      "sphinx.transforms.post_transforms.images",
      "sphinx.transforms.post_transforms.compat",
      "sphinx.util.compat",
      "sphinx.environment.collectors.dependencies",
      "sphinx.environment.collectors.asset",
      "sphinx.environment.collectors.metadata",
      "sphinx.environment.collectors.title",
      "sphinx.environment.collectors.toctree",
      "sphinx.environment.collectors.indexentries",
      "alabaster",
      "readthedocs_ext.readthedocs",
      "sphinx_autorun"
    ],
    "html_theme": "sphinx_rtd_theme",
    "name": "sphinx"
  },

[humitos]

It requires this diff to test it locally:

diff --git a/readthedocs/doc_builder/python_environments.py b/readthedocs/doc_builder/python_environments.py
index 1d2a8ffef..0bee30074 100644
--- a/readthedocs/doc_builder/python_environments.py
+++ b/readthedocs/doc_builder/python_environments.py
@@ -215,8 +215,10 @@ class Virtualenv(PythonEnvironment):
                 ),
                 self.project.get_feature_value(
                     Feature.USE_SPHINX_RTD_EXT_LATEST,
-                    positive='readthedocs-sphinx-ext',
-                    negative='readthedocs-sphinx-ext<2.2',
+                    # positive='readthedocs-sphinx-ext',
+                    # negative='readthedocs-sphinx-ext<2.2',
+                    positive='git+https://github.com/readthedocs/readthedocs-sphinx-ext@humitos/telemetry-extensions-theme#egg=readthedocs-sphinx-ext',
+                    negative='git+https://github.com/readthedocs/readthedocs-sphinx-ext@humitos/telemetry-extensions-theme#egg=readthedocs-sphinx-ext',
                 ),
             ])
             if not self.project.has_feature(Feature.USE_SPHINX_LATEST):

[ericholscher]

I dislike adding more features to our extension, but I do feel like the Sphinx run is the right place to gather this data.

[humitos]

I dislike adding more features to our extension, but I do feel like the Sphinx run is the right place to gather this data.

Yeah. Also, this approach will only works while we have control over the builds and automatically install our extension. We could think about a different of doing this in the future, but I think it's fine for now.