SymPy Bot

This is a GitHub bot for SymPy. It runs on Render and uses the @sympy-bot GitHub user.

The bot makes sure that every pull request to SymPy has a release notes entry in the pull request description. It then automatically adds these notes to the release notes on the wiki when the pull request is merged.

See the guide on the SymPy wiki on how to write release notes.

The bot may also do other things in the future. If you have any suggestions or have found any bugs, please open an issue. Pull requests are welcome too.

Setting up the bot

This tutorial is very good on how to set up Heroku and write GitHub bots. This bot is based on it, although it uses Render instead of Heroku.

The bot is tied to Render, so any push to this repo is automatically deployed there. The Redner dashboard is at https://dashboard.render.com/

If the bot stops working, look at the logs on the Render dashboard.

Next, you need to set up the bot on GitHub. To do so, follow these steps:

1. Go to the webhooks settings (for instance, at https://github.com/sympy/sympy/settings/hooks), and create a new webhook.

   • Set the payload URL to the Render app URL (for instance, https://sympy-bot.onrender.com/)
   • Set the content type to application/json
   • Generate a random password for the secret. I used the keychain app on my Mac to generate a 20 character password with random characters. Save this secret, as you will need to enter it in Render as well.
   • Under "Which events would you like to trigger this webhook?" select "Let me select individual events.". Then make sure only Pull requests is checked.
   • Make sure Active is checked

2. Go to the Render dashboard and click on "Environment" on the left side. Create two config variables:

   • GH_SECRET: set this to the secret you created in step 1 above
   • GH_AUTH: set this to the personal access token for the sympy-bot user. If you don't have this or need to regenerate it, login as the bot user and go to the personal access token settings (at https://github.com/settings/tokens), and create a new token. VERY IMPORTANT: Give the token public_repo access only.

3. Give the sympy-bot user push access to the repo. This is required for the bot to set commit statuses and to push to the wiki. If you know how to allow it to do this without giving it as much access, please let me know. I have tried playing with using reviews instead of statuses, but I couldn't get it to work.

Testing

To test, push to a separate branch (master has branch protection) on this repo (you can also set up a separate testing deploy for your fork if you want). Then go to the Render dashboard and manually deploy the branch. We may at some point enable automatic deployments for PRs in Render.

Debugging Webhooks

To debug webhooks, you can go to the webhooks settings for the repo the bot is set up on (e.g., https://github.com/sympy/sympy/settings/hooks), and click the webhook for https://sympy-bot.onrender.com/. This will show you all recent webhooks that were delivered, with the exact JSON that was delivered as well as the headers and the response. Each webhook has a corresponding UUID (the delivery id), which is printed by the bot in the logs when it receives it.

Rate Limits

GitHub has a rate limit of 5000 requests per hour. A single bot action may result in multiple API requests. You can see the current rate limit and when it resets at https://sympy-bot.onrender.com/. If the bot detects that its rate limits are getting very low, it will post a warning comment on a pull request. Right now, the bot doesn't use the API very much, so we never get near the rate limits, unless someone were to attempt to spam it. However, in the future, this could become an issue if the bot is made to do more stuff.