[luci_context] Move writing of LUCI_CONTEXT files to the engine core.

This removes an odd file-write from 'userspace' recipe code, but also
enables compuation of 'timeout' for the step much closer to the actual
step execution. Specifically, this avoids having 'timeout' also cover
the time that we block for resource contention when running multiple
greenlets in the recipe.

R=vadimsh, yiwzhang

Bug: 1127089
Change-Id: Iff59e7698e9556737a6144508c00cb3342811641
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/recipes-py/+/2441885
Reviewed-by: Yiwei Zhang <yiwzhang@google.com>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>
7 files changed
tree: 5e7bf3193955c9d82d87bc7ff7c657b8aac6aab8
  1. doc/
  2. infra/
  3. misc/
  4. recipe_engine/
  5. recipe_modules/
  6. recipe_proto/
  7. recipes/
  8. unittests/
  9. .gitattributes
  10. .gitignore
  11. .style.yapf
  12. .vpython
  13. AUTHORS
  14. codereview.settings
  15. CONTRIBUTORS
  16. LICENSE
  17. OWNERS
  18. PRESUBMIT.py
  19. README.md
  20. README.recipes.md
  21. recipes.py
README.md

Recipes

Recipes are a domain-specific language (embedded in python) for specifying sequences of subprocess calls in a cross-platform and testable way.

They allow writing build flows which integrate with the rest of LUCI.

Documentation for the recipe engine (including this file!). Take a look at the user guide for some hints on how to get started. See the implementation details doc for more detailed implementation information about the recipe engine.

Contributing

  • Sign the Google CLA.
  • Make sure your user.email and user.name are configured in git config.

Run the following to setup the code review tool and create your first review:

# Get `depot_tools` in $PATH if you don't have it
git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git $HOME/src/depot_tools
export PATH="$PATH:$HOME/src/depot_tools"

# Check out the recipe engine repo
git clone https://chromium.googlesource.com/infra/luci/recipes-py $HOME/src/recipes-py

# make your change
cd $HOME/src/recipes-py
git new-branch cool_feature
# hack hack
git commit -a -m "This is awesome"

# This will ask for your Google Account credentials.
git cl upload -s -r joe@example.com
# Wait for approval over email.
# Click "Submit to CQ" button or ask reviewer to do it for you.
# Wait for the change to be tested and landed automatically.

Use git cl help and git cl help <cmd> for more details.