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6th chunk of `content/manuals/engine/release-notes/18.09.md`
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In Docker versions prior to 18.09, containerd was managed by the Docker engine daemon. In Docker Engine 18.09, containerd is managed by systemd. Since containerd is managed by systemd, any custom configuration to the `docker.service` systemd
configuration which changes mount settings (for example, `MountFlags=slave`) breaks interactions between the Docker Engine daemon and containerd, and you will not be able to start containers.

Run the following command to get the current value of the `MountFlags` property for the `docker.service`:

```console
$ sudo systemctl show --property=MountFlags docker.service
MountFlags=
```

Update your configuration if this command prints a non-empty value for `MountFlags`, and restart the docker service.


### New features

* Updated API version to 1.39 [moby/moby#37640](https://github.com/moby/moby/pull/37640)
* Added support for remote connections using SSH [docker/cli#1014](https://github.com/docker/cli/pull/1014)
* Builder: added prune options to the API [moby/moby#37651](https://github.com/moby/moby/pull/37651)
* Added "Warnings" to `/info` endpoint, and move detection to the daemon [moby/moby#37502](https://github.com/moby/moby/pull/37502)
* Allows BuildKit builds to run without experimental mode enabled. Buildkit can now be configured with an option in daemon.json [moby/moby#37593](https://github.com/moby/moby/pull/37593) [moby/moby#37686](https://github.com/moby/moby/pull/37686) [moby/moby#37692](https://github.com/moby/moby/pull/37692) [docker/cli#1303](https://github.com/docker/cli/pull/1303)  [docker/cli#1275](https://github.com/docker/cli/pull/1275)
* Added support for build-time secrets using a `--secret` flag when using BuildKit [docker/cli#1288](https://github.com/docker/cli/pull/1288)
* Added SSH agent socket forwarder (`docker build --ssh $SSHMOUNTID=$SSH_AUTH_SOCK`) when using BuildKit [docker/cli#1438](https://github.com/docker/cli/pull/1438) / [docker/cli#1419](https://github.com/docker/cli/pull/1419)
* Added `--chown` flag support for `ADD` and `COPY` commands on Windows [moby/moby#35521](https://github.com/moby/moby/pull/35521)
* Added `builder prune` subcommand to prune BuildKit build cache [docker/cli#1295](https://github.com/docker/cli/pull/1295) [docker/cli#1334](https://github.com/docker/cli/pull/1334)
* BuildKit: Adds configurable garbage collection policy for the BuildKit build cache [docker/engine#59](https://github.com/docker/engine/pull/59) / [moby/moby#37846](https://github.com/moby/moby/pull/37846)
* BuildKit: Adds support for `docker build --pull ...` when using BuildKit [moby/moby#37613](https://github.com/moby/moby/pull/37613)
* BuildKit: Adds support or "registry-mirrors" and "insecure-registries" when using BuildKit [docker/engine#59](https://github.com/docker/engine/pull/59) / [moby/moby#37852](https://github.com/moby/moby/pull/37852)
* BuildKit: Enables net modes and bridge. [moby/moby#37620](https://github.com/moby/moby/pull/37620)
* Added `docker engine` subcommand to manage the lifecycle of a Docker Engine running as a privileged container on top of containerd, and to allow upgrades to Docker Engine Enterprise [docker/cli#1260](https://github.com/docker/cli/pull/1260)
* Exposed product license in `docker info` output [docker/cli#1313](https://github.com/docker/cli/pull/1313)
* Showed warnings produced by daemon in `docker info` output [docker/cli#1225](https://github.com/docker/cli/pull/1225)
* Added "local" log driver [moby/moby#37092](https://github.com/moby/moby/pull/37092)
* Amazon CloudWatch: adds `awslogs-endpoint` logging option [moby/moby#37374](https://github.com/moby/moby/pull/37374)
* Added support for global default address pools [moby/moby#37558](https://github.com/moby/moby/pull/37558) [docker/cli#1233](https://github.com/docker/cli/pull/1233)
* Configured containerd log-level to be the same as dockerd [moby/moby#37419](https://github.com/moby/moby/pull/37419)
* Added configuration option for cri-containerd [moby/moby#37519](https://github.com/moby/moby/pull/37519)
Title: Docker Engine 18.09: New Features and Containerd Management
Summary
This section of the Docker 18.09 release notes highlights changes to containerd management and introduces new features. Containerd is now managed by systemd, requiring configuration updates for custom mount settings. New features include API version updates (1.39), SSH remote connection support, builder prune options, warnings in the `/info` endpoint, BuildKit enhancements (running without experimental mode, build-time secrets, SSH agent socket forwarder), `--chown` flag support for Windows, `builder prune` subcommand, configurable garbage collection for BuildKit cache, `docker build --pull` support with BuildKit, support for registry mirrors and insecure registries with BuildKit. Additional features include the `docker engine` subcommand, product license exposure in `docker info`, daemon warnings in `docker info`, "local" log driver, Amazon CloudWatch logging options, global default address pools, and containerd log-level configuration.