fs2-kafka v2.0.0-RC1

This is the first release candidate for fs2-kafka v2.0.0, based on cats-effect 3.0. It is available for Scala 2.12, 2.13, and 3.0.0-RC2.

Revised roadmap

Previously we planned to release two new major versions: 2.0, based on cats-effect 2, and 3.0 based on cats-effect 3. However we no longer intend to release a new major version based on cats-effect 2, so fs2-kafka 2.0 will be based on cats-effect 3. This release candidate is therefore the successor to v3.0.0-M3.

We expect to release fs2-kafka 3.0, with further breaking changes, in the second half of 2021. The 1.x series will continue to receive bug fixes and some new features may be backported, but development will focus on the 2.x and 3.x series.

Migrating from v1.x

Before updating to v2.0.0-RC1, you should first update to v1.5.0 and fix any deprecation warnings. This process can mostly be automated with ScalaFix using scalafix --rules=github:fd4s/fs2-kafka/Fs2Kafka?sha=v1.5.0. (See here for how to add ScalaFix to your project.)

Apart from the migration to cats-effect 3.0, v2.0.0-RC1 makes only a few source-breaking changes from v1.5.0. Again, the migration can mostly be automated with Scalafix, using scalafix --rules=github:fd4s/fs2-kafka/Fs2Kafka?sha=v2.0.0-RC1.

• Reordering of passthrough parameters (#466): the P type parameter in ProducerRecords, TransactionalProducerRecords and ProducerResult has been moved to the left.
• Moving resource instantiation out of settings classes (#581). Classes such as ProducerSettings no longer have a createProducer method (etc) - instead, this capability is represented by separately by the MkProducer trait. Most user code will be unaffected by this change.

It is not binary-compatible with previous releases.