Codespaces: Scheduled prebuild configurations

Repository administrators can now configure how often/when prebuild configurations for a given branch should be updated. Prebuilds enable developers to startup Codespaces in seconds – regardless of repository size or complexity – by building your development environment beforehand. Previously, prebuild configurations were updated on every push made to a prebuild-enabled branch. During public beta, we heard from many repo admins requiring more control on how often their configurations should be updated based on their team’s processes as well costs associated with running Actions workflows to keep configurations up to date.

With this feature, admins can now make more nuanced trade-offs between environment “freshness” and Actions usage. For example, an admin working in a large organization may decide to update their prebuild configuration every hour rather than on every push to get the most economy and efficiency out of their Actions usage. While creating or updating prebuilds for a given repo and branch, repository admins can choose from three triggers to initiate a refresh:

• Every push (default): With this setting, prebuild configurations are updated on every push made to the given branch. This ensures that new Codespaces always contain the latest configuration, including any recently added or updated dependencies.
• On configuration change: With this setting, prebuild configurations are updated only when configuration files (ex. devcontainer) change. This ensures that developers always have access to a Codespace based on the latest configuration without having to run Actions workflows on every push made to the repo.
• Scheduled: With this setting, you can have your prebuild configurations update on a custom schedule only, regardless of any pushes made to the branch or updates made to associated configuration files. This can further reduce consumption of Actions minutes and give admins even more control on how often configurations should be updated.

For more information, see Configuring prebuilds for your repository