The `/etc/docker` directory is used both by the dockerd daemon
and the docker cli (if installed on the saem host as the daemon).
In situations where the `/etc/docker` directory does not exist,
and an initial `key.json` (legacy trust key) is generated (at the
default location), the `/etc/docker/` directory was created with
0700 permissions, making the directory only accessible by `root`.
Given that the `0600` permissions on the key itself already protect
it from being used by other users, the permissions of `/etc/docker`
can be less restrictive.
This patch changes the permissions for the directory to `0755`, so
that the CLI (if executed as non-root) can also access this directory.
> **NOTE**: "strictly", this patch is only needed for situations where no _custom_
> location for the trustkey is specified (not overridden with `--deprecated-key-path`),
> but setting the permissions only for the "default" case would make
> this more complicated.
```bash
make binary shell
make install
ls -la /etc/ | grep docker
dockerd
^C
ls -la /etc/ | grep docker
drwxr-xr-x 2 root root 4096 Sep 14 12:11 docker
```
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
