Docker Runtime and Networking Enhancements

- cgroup2: use "systemd" cgroup driver by default when available [moby/moby#40846](https://github.com/moby/moby/pull/40846) - new storage driver: fuse-overlayfs [moby/moby#40483](https://github.com/moby/moby/pull/40483) - Update containerd binary to v1.4.3 [moby/moby#41732](https://github.com/moby/moby/pull/41732) - `docker push` now defaults to `latest` tag instead of all tags [moby/moby#40302](https://github.com/moby/moby/pull/40302) - Added ability to change the number of reconnect attempts during connection loss while pulling an image by adding max-download-attempts to the config file [moby/moby#39949](https://github.com/moby/moby/pull/39949) - Add support for containerd v2 shim by using the now default `io.containerd.runc.v2` runtime [moby/moby#41182](https://github.com/moby/moby/pull/41182) - cgroup v1: change the default runtime to io.containerd.runc.v2. Requires containerd v1.3.0 or later. v1.3.5 or later is recommended [moby/moby#41210](https://github.com/moby/moby/pull/41210) - Start containers in their own cgroup namespaces [moby/moby#38377](https://github.com/moby/moby/pull/38377) - Enable DNS Lookups for CIFS Volumes [moby/moby#39250](https://github.com/moby/moby/pull/39250) - Use MemAvailable instead of MemFree to estimate actual available memory [moby/moby#39481](https://github.com/moby/moby/pull/39481) - The `--device` flag in `docker run` will now be honored when the container is started in privileged mode [moby/moby#40291](https://github.com/moby/moby/pull/40291) - Enforce reserved internal labels [moby/moby#40394](https://github.com/moby/moby/pull/40394) - Raise minimum memory limit to 6M, to account for higher memory use by runtimes during container startup [moby/moby#41168](https://github.com/moby/moby/pull/41168) - vendor runc v1.0.0-rc92 [moby/moby#41344](https://github.com/moby/moby/pull/41344) [moby/moby#41317](https://github.com/moby/moby/pull/41317) - info: add warnings about missing blkio cgroup support [moby/moby#41083](https://github.com/moby/moby/pull/41083) - Accept platform spec on container create [moby/moby#40725](https://github.com/moby/moby/pull/40725) - Fix handling of looking up user- and group-names with spaces [moby/moby#41377](https://github.com/moby/moby/pull/41377) ### Networking - Support host.docker.internal in dockerd on Linux [moby/moby#40007](https://github.com/moby/moby/pull/40007) - Include IPv6 address of linked containers in /etc/hosts [moby/moby#39837](https://github.com/moby/moby/pull/39837) - `--ip6tables` enables IPv6 iptables rules (only if experimental) [moby/moby#41622](https://github.com/moby/moby/pull/41622) - Add alias for hostname if hostname != container name [moby/moby#39204](https://github.com/moby/moby/pull/39204) - Better selection of DNS server (with systemd) [moby/moby#41022](https://github.com/moby/moby/pull/41022) - Add docker interfaces to firewalld docker zone [moby/moby#41189](https://github.com/moby/moby/pull/41189) [moby/libnetwork#2548](https://github.com/moby/libnetwork/pull/2548) - Fixes DNS issue on CentOS8 [docker/for-linux#957](https://github.com/docker/for-linux/issues/957) - Fixes Port Forwarding on RHEL 8 with Firewalld running with FirewallBackend=nftables [moby/libnetwork#2496](https://github.com/moby/libnetwork/issues/2496) - Fix an issue reporting 'failed to get network during CreateEndpoint' [moby/moby#41189](https://github.com/moby/moby/pull/41189) [moby/libnetwork#2554](https://github.com/moby/libnetwork/pull/2554) - Log error instead of disabling IPv6 router advertisement failed [moby/moby#41189](https://github.com/moby/moby/pull/41189) [moby/libnetwork#2563](https://github.com/moby/libnetwork/pull/2563) - No longer ignore `--default-address-pool` option in certain cases [moby/moby#40711](https://github.com/moby/moby/pull/40711)

This section outlines updates to Docker's runtime and networking components. Runtime enhancements include default cgroup driver changes, the addition of a fuse-overlayfs storage driver, an updated containerd binary, defaulting `docker push` to the `latest` tag, and support for containerd v2 shim. There are also improvements in memory management, device flag handling in privileged mode, and updated runc version. Networking updates introduce support for `host.docker.internal` on Linux, IPv6 address inclusion for linked containers, and improved DNS server selection. It also features better integration with firewalld and various bug fixes related to network creation and IPv6.