Sourced from github.com/docker/docker's releases.

v28.0.0

28.0.0

For a full list of pull requests and changes in this release, refer to the relevant GitHub milestones:

• docker/cli, 28.0.0 milestone
• moby/moby, 28.0.0 milestone
• Deprecated and removed features, see Deprecated Features.
• Changes to the Engine API, see API version history.

New

• Add ability to mount an image inside a container via --mount type=image. moby/moby#48798
  • You can also specify --mount type=image,image-subpath=[subpath],... option to mount a specific path from the image. docker/cli#5755
• docker images --tree now shows metadata badges. docker/cli#5744
• docker load, docker save, and docker history now support a --platform flag allowing you to choose a specific platform for single-platform operations on multi-platform images. docker/cli#5331
• Add OOMScoreAdj to docker service create and docker stack. docker/cli#5145
• docker buildx prune now supports reserved-space, max-used-space, min-free-space and keep-bytes filters. moby/moby#48720
• Windows: Add support for running containerd as a child process of the daemon, instead of using a system-installed containerd. moby/moby#47955

Networking

• The docker-proxy binary has been updated, older versions will not work with the updated dockerd. moby/moby#48132
  • Close a window in which the userland proxy (docker-proxy) could accept TCP connections, that would then fail after iptables NAT rules were set up.
  • The executable rootlesskit-docker-proxy is no longer used, it has been removed from the build and distribution.
• DNS nameservers read from the host's /etc/resolv.conf are now always accessed from the host's network namespace. moby/moby#48290
  • When the host's /etc/resolv.conf contains no nameservers and there are no --dns overrides, Google's DNS servers are no longer used, apart from by the default bridge network and in build containers.
• Container interfaces in bridge and macvlan networks now use randomly generated MAC addresses. moby/moby#48808
  • Gratuitous ARP / Neighbour Advertisement messages will be sent when the interfaces are started so that, when IP addresses are reused, they're associated with the newly generated MAC address.
  • IPv6 addresses in the default bridge network are now IPAM-assigned, rather than being derived from the MAC address.
• The deprecated OCI prestart hook is now only used by build containers. For other containers, network interfaces are added to the network namespace after task creation is complete, before the container task is started. moby/moby#47406
• Add a new gw-priority option to docker run, docker container create, and docker network connect. This option will be used by the Engine to determine which network provides the default gateway for a container. On docker run, this option is only available through the extended --network syntax. docker/cli#5664
• Add a new netlabel com.docker.network.endpoint.ifname to customize the interface name used when connecting a container to a network. It's supported by all built-in network drivers on Linux. moby/moby#49155
  • When a container is created with multiple networks specified, there's no guarantee on the order networks will be connected to the container. So, if a custom interface name uses the same prefix as the auto-generated names, for example eth, the container might fail to start.
  • The recommended practice is to use a different prefix, for example en0, or a numerical suffix high enough to never collide, for example eth100.
  • This label can be specified on docker network connect via the --driver-opt flag, for example docker network connect --driver-opt=com.docker.network.endpoint.ifname=foobar ….
  • Or via the long-form --network flag on docker run, for example docker run --network=name=bridge,driver-opt=com.docker.network.endpoint.ifname=foobar …
• If a custom network driver reports capability GwAllocChecker then, before a network is created, it will get a GwAllocCheckerRequest with the network's options. The custom driver may then reply that no gateway IP address should be allocated. moby/moby#49372

Port publishing in bridge networks

• dockerd now requires ipset support in the Linux kernel. moby/moby#48596
  • The iptables and ip6tables rules used to implement port publishing and network isolation have been extensively modified. This enables some of the following functional changes, and is a first step in refactoring to enable native nftables support in a future release. moby/moby#48815
  • If it becomes necessary to downgrade to an earlier version of the daemon, some manual cleanup of the new rules will be necessary. The simplest and surest approach is to reboot the host, or use iptables -F and ip6tables -F to flush all existing iptables rules from the filter table before starting the older version of the daemon. When that is not possible, run the following commands as root:
    • iptables -D FORWARD -m set --match-set docker-ext-bridges-v4 dst -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT; ip6tables -D FORWARD -m set --match-set docker-ext-bridges-v6 dst -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
    • iptables -D FORWARD -m set --match-set docker-ext-bridges-v4 dst -j DOCKER; ip6tables -D FORWARD -m set --match-set docker-ext-bridges-v6 dst -j DOCKER
    • If you were previously running with the iptables filter-FORWARD policy set to ACCEPT and need to restore access to unpublished ports, also delete per-bridge-network rules from the DOCKER chains. For example, iptables -D DOCKER ! -i docker0 -o docker0 -j DROP.
• Fix a security issue that was allowing remote hosts to connect directly to a container on its published ports. moby/moby#49325
• Fix a security issue that was allowing neighbor hosts to connect to ports mapped on a loopback address. moby/moby#49325

... (truncated)

• af898ab Merge pull request #49495 from vvoland/update-buildkit
• d67f035 vendor: github.com/moby/buildkit v0.20.0
• 00ab386 Merge pull request #49491 from vvoland/update-buildkit
• 1fde8c4 builder-next: fix cdi manager
• cde9f07 vendor: github.com/moby/buildkit v0.20.0-rc3
• 89e1429 Merge pull request #49490 from thaJeztah/dockerfile_linting
• b2b5590 Dockerfile: fix linting warnings
• 62bc597 Merge pull request #49480 from thaJeztah/docs_api_1.48
• 670cd81 Merge pull request #49485 from vvoland/c8d-list-panic
• a3628f3 docs/api: add documentation for API v1.48
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