Docker Engine 29.3 Ships with Native gRPC Support and BuildKit v0.28

Docker Engine 29.3.0 has been released with native gRPC support, BuildKit v0.28.0, and backward-compatibility improvements that extend the minimum supported API version back to Docker 19.03. The release continues Docker's cadence of monthly point releases that add features while maintaining stability for production environments.

Native gRPC Support

Docker Engine's listening socket now natively handles gRPC connections alongside the existing REST API. This enables richer, bidirectional communication between Docker clients and the daemon, with support for streaming responses that are more efficient than the long-polling mechanisms used by the REST API for operations like container log tailing and build progress tracking.

The gRPC interface is opt-in and coexists with the REST API — existing tooling and scripts continue to work without modification. Container orchestration tools and monitoring systems can use the gRPC interface for lower-latency interactions with the Docker daemon.

BuildKit v0.28.0

The integrated BuildKit build engine has been updated to version 0.28.0, which includes improvements to cache management, multi-platform build performance, and Dockerfile frontend capabilities. A new bind-create-src option for the --mount flag allows bind mounts to automatically create the source directory on the host if it doesn't exist — eliminating a common error when mounting paths in CI environments where directory structures aren't pre-created.

Backward Compatibility

The minimum API version has been lowered from v1.44 to v1.40, corresponding to Docker Engine 19.03. This means older Docker clients can communicate with Docker Engine 29.3 without version negotiation failures — important for environments where upgrading all clients simultaneously isn't practical. CLI plugin hooks now fire on command failure in addition to success, enabling plugins to provide diagnostic hints when commands fail.

Bug Fixes

A notable fix addresses DNS configuration corruption during daemon reloads. Previously, reloading the Docker daemon configuration (via SIGHUP or the /reload API) could corrupt the DNS resolver configuration for running containers, causing intermittent name resolution failures. The fix ensures that DNS configuration is atomically updated during reloads. Network endpoint handling has also been improved, with POST /networks/{id}/connect now correctly applying the MacAddress field in EndpointSettings.