"Failed to get a tun/tap device" when starting a lighthouse on digital ocean droplet

Encounter the following fetal error when starting a lighthouse using a digital ocean droplet running CentOS 7 x86

/opt/nebula/nebula -config /opt/nebula/config.yml
INFO[0000] Firewall rule added                           firewallRule="map[caName: caSha: direction:outgoing endPort:0 groups:[] host:any ip:<nil> proto:0 startPort:0]"
INFO[0000] Firewall rule added                           firewallRule="map[caName: caSha: direction:incoming endPort:0 groups:[] host:any ip:<nil> proto:1 startPort:0]"
INFO[0000] Firewall rule added                           firewallRule="map[caName: caSha: direction:incoming endPort:443 groups:[laptop home] host: ip:<nil> proto:6 startPort:443]"
INFO[0000] Firewall started                              firewallHash=853d3005de969aa0cb1100731e983a740ab4218f89c78189edd389ff5e05ae99
FATA[0000] Failed to get a tun/tap device                error="no such file or directory"

[root ~]# cat /etc/redhat-release 
CentOS Linux release 7.3.1611 (Core)

[root ~]# lsmod
Module                  Size  Used by
ext4                  578819  1 
mbcache                14958  1 ext4
jbd2                  102940  1 ext4
ata_generic            12910  0 
pata_acpi              13038  0 
virtio_net             28024  0 
virtio_blk             18156  2 
virtio_scsi            18361  0 
crct10dif_pclmul       14289  0 
crct10dif_common       12595  1 crct10dif_pclmul
crc32c_intel           22079  0 
ata_piix               35038  0 
serio_raw              13462  0 
virtio_pci             22913  0 
virtio_ring            21524  4 virtio_blk,virtio_net,virtio_pci,virtio_scsi
virtio                 15008  4 virtio_blk,virtio_net,virtio_pci,virtio_scsi
libata                218730  3 pata_acpi,ata_generic,ata_piix
floppy                 69417  0 

[root ~]# uname -a
Linux xxxxx 3.10.0-327.4.5.el7.x86_64 #1 SMP Mon Jan 25 22:07:14 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

The documentation no mention about tun device, am I missing some setup steps?

[root@admundo ~]# cat /opt/nebula/config.yml 
# This is the nebula example configuration file. You must edit, at a minimum, the static_host_map, lighthouse, and firewall sections
# Some options in this file are HUPable, including the pki section. (A HUP will reload credentials from disk without affecting existing tunnels)

# PKI defines the location of credentials for this node. Each of these can also be inlined by using the yaml ": |" syntax.
pki:
  # The CAs that are accepted by this node. Must contain one or more certificates created by 'nebula-cert ca'
  ca: /opt/nebula/ca.crt
  cert: /opt/nebula/host.crt
  key: /opt/nebula/host.key
  #blacklist is a list of certificate fingerprints that we will refuse to talk to
  #blacklist:
  #  - c99d4e650533b92061b09918e838a5a0a6aaee21eed1d12fd937682865936c72

# The static host map defines a set of hosts with fixed IP addresses on the internet (or any network).
# A host can have multiple fixed IP addresses defined here, and nebula will try each when establishing a tunnel.
# The syntax is:
#   "{nebula ip}": ["{routable ip/dns name}:{routable port}"]
# Example, if your lighthouse has the nebula IP of 192.168.100.1 and has the real ip address of 100.64.22.11 and runs on port 4242:
static_host_map:
  "192.168.200.10": ["188.226.141.122:4242"]

lighthouse:
  # am_lighthouse is used to enable lighthouse functionality for a node. This should ONLY be true on nodes
  # you have configured to be lighthouses in your network
  am_lighthouse: true
  # serve_dns optionally starts a dns listener that responds to various queries and can even be
  # delegated to for resolution
  #serve_dns: false
  #dns:
    # The DNS host defines the IP to bind the dns listener to. This also allows binding to the nebula node IP.
    #host: 0.0.0.0
    #port: 53
  # interval is the number of seconds between updates from this node to a lighthouse.
  # during updates, a node sends information about its current IP addresses to each node.
  interval: 60
  # hosts is a list of lighthouse hosts this node should report to and query from
  # IMPORTANT: THIS SHOULD BE EMPTY ON LIGHTHOUSE NODES
  hosts:
  #  - "192.168.100.1"

# Port Nebula will be listening on. The default here is 4242. For a lighthouse node, the port should be defined,
# however using port 0 will dynamically assign a port and is recommended for roaming nodes.
listen:
  host: 0.0.0.0
  port: 4242
  # Sets the max number of packets to pull from the kernel for each syscall (under systems that support recvmmsg)
  # default is 64, does not support reload
  #batch: 64
  # Configure socket buffers for the udp side (outside), leave unset to use the system defaults. Values will be doubled by the kernel
  # Default is net.core.rmem_default and net.core.wmem_default (/proc/sys/net/core/rmem_default and /proc/sys/net/core/rmem_default)
  # Maximum is limited by memory in the system, SO_RCVBUFFORCE and SO_SNDBUFFORCE is used to avoid having to raise the system wide
  # max, net.core.rmem_max and net.core.wmem_max
  #read_buffer: 10485760
  #write_buffer: 10485760

# Punchy continues to punch inbound/outbound at a regular interval to avoid expiration of firewall nat mappings
punchy: true
# punch_back means that a node you are trying to reach will connect back out to you if your hole punching fails
# this is extremely useful if one node is behind a difficult nat, such as symmetric
#punch_back: true

# Cipher allows you to choose between the available ciphers for your network.
# IMPORTANT: this value must be identical on ALL NODES/LIGHTHOUSES. We do not/will not support use of different ciphers simultaneously!
#cipher: chachapoly

# Local range is used to define a hint about the local network range, which speeds up discovering the fastest
# path to a network adjacent nebula node.
#local_range: "172.16.0.0/24"

# sshd can expose informational and administrative functions via ssh this is a
#sshd:
  # Toggles the feature
  #enabled: true
  # Host and port to listen on, port 22 is not allowed for your safety
  #listen: 127.0.0.1:2222
  # A file containing the ssh host private key to use
  # A decent way to generate one: ssh-keygen -t ed25519 -f ssh_host_ed25519_key -N "" < /dev/null
  #host_key: ./ssh_host_ed25519_key
  # A file containing a list of authorized public keys
  #authorized_users:
    #- user: steeeeve
      # keys can be an array of strings or single string
      #keys:
        #- "ssh public key string"

# Configure the private interface. Note: addr is baked into the nebula certificate
tun:
  # Name of the device
  dev: nebula1
  # Toggles forwarding of local broadcast packets, the address of which depends on the ip/mask encoded in pki.cert
  drop_local_broadcast: false
  # Toggles forwarding of multicast packets
  drop_multicast: false
  # Sets the transmit queue length, if you notice lots of transmit drops on the tun it may help to raise this number. Default is 500
  tx_queue: 500
  # Default MTU for every packet, safe setting is (and the default) 1300 for internet based traffic
  mtu: 1300
  # Route based MTU overrides, you have known vpn ip paths that can support larger MTUs you can increase/decrease them here
  routes:
    #- mtu: 8800
    #  route: 10.0.0.0/16
  # Unsafe routes allows you to route traffic over nebula to non-nebula nodes
  # Unsafe routes should be avoided unless you have hosts/services that cannot run nebula
  # NOTE: The nebula certificate of the "via" node *MUST* have the "route" defined as a subnet in its certificate
  unsafe_routes:
    #- route: 172.16.1.0/24
    #  via: 192.168.100.99
    #  mtu: 1300 #mtu will default to tun mtu if this option is not sepcified

# TODO
# Configure logging level
logging:
  # panic, fatal, error, warning, info, or debug. Default is info
  level: info
  # json or text formats currently available. Default is text
  format: text

#stats:
  #type: graphite
  #prefix: nebula
  #protocol: tcp
  #host: 127.0.0.1:9999
  #interval: 10s

  #type: prometheus
  #listen: 127.0.0.1:8080
  #path: /metrics
  #namespace: prometheusns
  #subsystem: nebula
  #interval: 10s

# Nebula security group configuration
firewall:
  conntrack:
    tcp_timeout: 120h
    udp_timeout: 3m
    default_timeout: 10m
    max_connections: 100000

  # The firewall is default deny. There is no way to write a deny rule.
  # Rules are comprised of a protocol, port, and one or more of host, group, or CIDR
  # Logical evaluation is roughly: port AND proto AND (ca_sha OR ca_name) AND (host OR group OR groups OR cidr)
  # - port: Takes `0` or `any` as any, a single number `80`, a range `200-901`, or `fragment` to match second and further fragments of fragmented packets (since there is no port available).
  #   code: same as port but makes more sense when talking about ICMP, TODO: this is not currently implemented in a way that works, use `any`
  #   proto: `any`, `tcp`, `udp`, or `icmp`
  #   host: `any` or a literal hostname, ie `test-host`
  #   group: `any` or a literal group name, ie `default-group`
  #   groups: Same as group but accepts a list of values. Multiple values are AND'd together and a certificate would have to contain all groups to pass
  #   cidr: a CIDR, `0.0.0.0/0` is any.
  #   ca_name: An issuing CA name
  #   ca_sha: An issuing CA shasum

  outbound:
    # Allow all outbound traffic from this node
    - port: any
      proto: any
      host: any

  inbound:
    # Allow icmp between any nebula hosts
    - port: any
      proto: icmp
      host: any

    # Allow tcp/443 from any host with BOTH laptop and home group
    - port: 443
      proto: tcp
      groups:
        - laptop
        - home

slackhq / nebula

"Failed to get a tun/tap device" when starting a lighthouse on digital ocean droplet #178