Running TYPO3 Cron inside the web container

This recipe provides two completely different techniques to do TYPO3 cron inside the web container.

Enable Linux cron on ddev start and have it run the TYPO3 cron every minute or
Just run a custom command (ddev cron) which will ddev exec the TYPO3 cron process every 60 seconds. (Run it in a separate window.)

Enable cronjob on start or on demand

Install the ddev cron custom command commands/web/cron in your .ddev/commands/web directory. Make sure that it's executable (chmod +x .ddev/commands/web/cron). This allows you to simulate a real cron job by just running ddev cron in a separate window and it
Place config.cron.yml in the .ddev directory (or add it to your .ddev/config.yaml); it will run the custom ddev cron command on project start, which will run a cronjob for typo3 scheduler:run every minute.
Change config.cron.yml to use your username instead of "root" in the first hook. (You can verify your in-container username with ddev exec id -un). (So for user rfay, - exec: echo '*/1 * * * * root TYPO3_CONTEXT=Development/Local /usr/bin/php /var/www/html/public/typo3/sysext/core/bin/typo3 scheduler:run' | sudo tee -a /etc/cron.d/typo3 would become - exec: echo '*/1 * * * * rfay TYPO3_CONTEXT=Development/Local /usr/bin/php /var/www/html/public/typo3/sysext/core/bin/typo3 scheduler:run' | sudo tee -a /etc/cron.d/typo3)

To run the TYPO3 cron process every 60 seconds, use the ddev cron custom command provided here.

Install commands/web/cron into your project's .ddev/commands/web directory.
Make it executable (chmod +x .ddev/commands/web/cron)
After starting the project, run ddev cron in a separate window and let it do its job.

Contributed by @thomaskieslich