diff --git a/CHANGELOG.md b/CHANGELOG.md index 71d91e49e6..dd384bd4f9 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -7,6 +7,36 @@ be found. ## 1.12.0 (2016-07-14) + +**IMPORTANT**: + +Docker 1.12.0 ships with an updated systemd unit file for rpm based installs +(which includes RHEL, Fedora, CentOS, and Oracle Linux 7). When upgrading from +an older version of docker, the upgrade process may not automatically install +the updated version of the unit file, or fail to start the docker service if; + +- the systemd unit file (`/usr/lib/systemd/system/docker.service`) contains local changes, or +- a systemd drop-in file is present, and contains `-H fd://` in the `ExecStart` directive + +Starting the docker service will produce an error: + + Failed to start docker.service: Unit docker.socket failed to load: No such file or directory. + +or + + no sockets found via socket activation: make sure the service was started by systemd. + +To resolve this: + +- Backup the current version of the unit file, and replace the file with the + version that ships with docker 1.12 (https://raw.githubusercontent.com/docker/docker/v1.12.0/contrib/init/systemd/docker.service.rpm) +- Remove the `Requires=docker.socket` directive from the `/usr/lib/systemd/system/docker.service` file if present +- Remove `-H fd://` from the `ExecStart` directive (both in the main unit file, and in any drop-in files present). + +After making those changes, run `sudo systemctl daemon-reload`, and `sudo +systemctl restart docker` to reload changes and (re)start the docker daemon. + + ### Builder + New `HEALTHCHECK` Dockerfile instruction to support user-defined healthchecks [#23218](https://github.com/docker/docker/pull/23218)