Shutting down my server
Attempting to use this for my Ubuntu server for WOL and shutdown. I'm using oznu/docker-homebridge setup on a pi Zero W. I'm able to WOL without problems, and ping is obviously working as the status is correct in the Home app. 

I'm unable to successfully perform a poweroff command via this accessory. I have tried a few things to see what's happening but I'm at a loss.

from config.json:
`        {
            "accessory": "NetworkDevice",
            "name": "Server",
            "mac": "<mac-address>",
            "ip": "x.x.x.x",
            "pingInterval": 45,
            "wakeGraceTime": 120,
            "shutdownGraceTime": 15,
            "shutdownCommand": "ssh -v user@x.x.x.x sudo poweroff"
        },`

This is what I see when I view the logs after switching off the server in the home app:

`[2018-7-10 13:53:45] [Server] NetworkDevice shutdown cycle started for "Server" (x.x.x.x)
[2018-7-10 13:53:45] [Server] Attempting to shut down "Server" (x.x.x.x) using "ssh -v user@x.x.x.x sudo poweroff"
[2018-7-10 13:53:45] [Server] NetworkDevice "Server" (x.x.x.x) went from status "Online" to "Shutting Down"
[2018-7-10 13:53:46] [Server] An error occured while trying to shut down "Server" (x.x.x.x): Error: Command failed: ssh -v user@x.x.x.x sudo poweroff
OpenSSH_7.5p1-hpn14v4, LibreSSL 2.6.3
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to x.x.x.x [x.x.x.x] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /config/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /config/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /config/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /config/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /config/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /config/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /config/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /config/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.5p1-hpn14v4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.4
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.4 pat OpenSSH* compat 0x04000000
debug1: Remote is NON-HPN aware
debug1: Authenticating to x.x.x.x:22 as 'USER'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:<DETAIL REMOVED>
debug1: read_passphrase: can't open /dev/tty: No such device or address
Host key verification failed.

[2018-7-10 13:53:46] [Server] NetworkDevice "Server" (x.x.x.x) went from status "Shutting Down" to "Online"`

I've managed to do this exact command from a terminal session within the docker container (using homebridge-config-ui-x), which seems to run as root. I am able to ssh into the server without a password, so my key is correctly installed. I have made sure my user on the server is full sudo access. 

What I can't figure out is "who" is performing the command. Is it run as root within the container? What's the difference between running the command in a terminal session, and running the command via the homebridge instance?

Pulling my (thinning) hair out, any help is appreciated 

Steve
