9. Use Renovate to update dependencies#

9.1. Status#


9.2. Context#

To ensure that the 3rd-party JavaScript packages we depend on get updated routinely (for security patches, bug fixes, etc.), we use a service to regularly create pull requests that update them. These pull requests notify us that the dependency has been updated and trigger test runs to check if the dependency can be safely upgraded without breaking functionality.

Why we use a service like this:

  • Security problems are occasionally found in packages we use, and we want to upgrade to versions that fix them as soon as possible to avoid being targeted by attacks

  • It’s not uncommon to spend hours debugging a problem which turns out to be a bug in a package which was already fixed in a newer release

  • Upgrading existing dependencies in a pull request to add a feature or fix a bug distracts reviewers from the actual changes that had to be made

  • Manually creating pull requests to upgrade dependencies (and circling back to check the results) is an inefficient use of developer time given that this is easily automated

9.3. Decision/Consequence#

The Open edX community uses Renovate to automate updates for frontend dependencies.

9.4. Rejected Alternatives#

  1. Greenkeeper

    • With Greenkeeper, each package to be upgraded got its own pull request on every release, which was good for identifying the root cause of a test failure but resulted in a pretty high volume of PRs that needed to be reviewed (especially in repositories which normally don’t need to be updated very often). Renovate has configuration options to set the frequency of checking for new dependency releases, and to allow related packages to be updated in the same pull request. This may delay notification of security patch releases or make it harder to identify the exact cause of a test failure, but also makes it less likely that the PRs will be simply ignored for lack of time to deal with them all.

    • package-lock.json was updated with each pull request, which often caused merge conflicts as different PRs changed the file in slightly incompatible ways. Some of the Renovate configuration options can make such conflicts less frequent, and when auto-merging is enabled (for specific packages when tests pass), it automatically rebases other pending pull requests.

    • Greenkeeper was discontinued in June 2020