Docker Engine 26.0.0 Release Notes: Bug Fixes, API Updates, and Packaging

> > By default, IPv6 will remain enabled on a container's loopback interface when the container is not connected to an IPv6-enabled network. > For example, containers that are only connected to an IPv4-only network now have the `::1` address on their loopback interface. > > To disable IPv6 in a container, > use option `--sysctl net.ipv6.conf.all.disable_ipv6=1` in the `create` or `run` command, > or the equivalent `sysctls` option in the service configuration section of a Compose file. > > If IPv6 is not available in a container because it has been explicitly disabled for the container, > or the host's networking stack does not have IPv6 enabled (or for any other reason) > the container's `/etc/hosts` file will not include IPv6 entries. - Fix `ADD` Dockerfile instruction failing with `lsetxattr <file>: operation not supported` when unpacking archive with xattrs onto a filesystem that doesn't support them. [moby/moby#47175](https://github.com/moby/moby/pull/47175) - Fix `docker container start` failing when used with `--checkpoint`. [moby/moby#47456](https://github.com/moby/moby/pull/47456) - Restore IP connectivity between the host and containers on an internal bridge network. [moby/moby#47356](https://github.com/moby/moby/pull/47356) - Do not enforce new validation rules for existing swarm networks. [moby/moby#47361](https://github.com/moby/moby/pull/47361) - Restore DNS names for containers in the default "nat" network on Windows. [moby/moby#47375](https://github.com/moby/moby/pull/47375) - Print hint when invoking `docker image ls` with ambiguous argument. [docker/cli#4849](https://github.com/docker/cli/pull/4849) - Cleanup `@docker_cli_[UUID]` files on OpenBSD. [docker/cli#4862](https://github.com/docker/cli/pull/4862) - Add explicit [deprecation notice](https://github.com/docker/cli/blob/v26.0.0/docs/deprecated.md#unauthenticated-tcp-connections) message when using remote TCP connections without TLS. [docker/cli#4928](https://github.com/docker/cli/pull/4928), [moby/moby#47556](https://github.com/moby/moby/pull/47556) - Use IPv6 nameservers from the host's `resolv.conf` as upstream resolvers for Docker Engine's internal DNS, rather than listing them in the container's `resolv.conf`. [moby/moby#47512](https://github.com/moby/moby/pull/47512) - containerd image store: Isolate images with different containerd namespaces when `--userns-remap` option is used. [moby/moby#46786](https://github.com/moby/moby/pull/46786) - containerd image store: Fix image pull not emitting `Pulling fs layer` status. [moby/moby#47432](https://github.com/moby/moby/pull/47432) ### API - To preserve backwards compatibility, read-only mounts are not recursive by default when using older clients (API version < v1.44). [moby/moby#47391](https://github.com/moby/moby/pull/47391) - `GET /images/{id}/json` omits the `Created` field (previously it was `0001-01-01T00:00:00Z`) if the `Created` field is missing from the image config. [moby/moby#47451](https://github.com/moby/moby/pull/47451) - Populate a missing `Created` field in `GET /images/{id}/json` with `0001-01-01T00:00:00Z` for API version <= 1.43. [moby/moby#47387](https://github.com/moby/moby/pull/47387) - The `is_automated` field in the `POST /images/search` endpoint results is always `false` now. Consequently, searching for `is-automated=true` will yield no results, while `is-automated=false` will be a no-op. [moby/moby#47465](https://github.com/moby/moby/pull/47465) - Remove `Container` and `ContainerConfig` fields from the `GET /images/{name}/json` response. [moby/moby#47430](https://github.com/moby/moby/pull/47430) ### Packaging updates - Update BuildKit to [v0.13.1](https://github.com/moby/buildkit/releases/tag/v0.13.1). [moby/moby#47582](https://github.com/moby/moby/pull/47582)

This section of the Docker Engine 26.0.0 release notes details various bug fixes and enhancements, including fixes for `ADD` instruction failures, `docker container start` issues with checkpoints, and IP connectivity problems. It addresses issues with swarm networks, DNS resolution on Windows, and provides a hint for ambiguous arguments with `docker image ls`. Deprecation notices are added for remote TCP connections without TLS. The section also covers API updates related to read-only mounts, the `Created` field in image JSON responses, and the removal of fields from the `GET /images/{name}/json` response. Finally, it mentions packaging updates, including an update to BuildKit v0.13.1.