.TH nebula.yml "5" "July 2021" "nebula 1.4.0"

.SH NAME
.B nebula.yml
- nebula configuration files

.SH DESCRIPTION

Configuration file for nebula(1) are written in YAML. Each section is described below:

.SS pki
The PKI section defines the location of credentials
.IP ca
  Path to the CA certificate
.IP cert
  Path to this node's certificate file
.IP key
  Path to this node's key file

.SS static_host_map
The static host map defines a set of hosts with fixed IP addresses on the internet. Multiple addresses may be defined and Nebula will try each when establishing a tunnel.

.SS lighthouse
The lighthouse section allows the entablement and configuration of lighthouse behavior. In Nebula, lighthouses are nodes with ip fixed addresses which other nodes can use to located each other.

.IP am_lighthouse
Enables lighthouse behavior on this node. Should ONLY be true on nodes you have configured to be lighthouses on your network.

.IP interval
Number of seconds between updates from this node to a lighthouse. When a lighthouse receives an update, it sends information about its current IP address to each node.

.IP hosts
A list of lighthouse nodes this node should report to and query from. Should be empty on lighthouse nodes.

.IP serve_dns
Starts a DNS listener which responds to various queries (VAGUE) and be delegated for resolution.

.SS listen
Control the port and interface on which nebula listens.

.IP host
Set the ip to which nebula binds

.IP port
Set the port to which nebula binds

.SS punchy

.IP punch
Continue to punch inbound/outbound at a regular interval to avoid expiration of firewall NAT mapping

.IP respond
Configure the node to reach out and connect to you if your hole punching fails. This is extremely useful if one node is behind a difficult NAT, such as a symmetric NAT.

.IP delay
Delay a punch response for misbehaving NATs, default is 1 second, respond must be true to take effect

.SS cipher
Choose between the available ciphers for your network. Options are "chachapoly" or "aes." Must be identical across all nodes on a network.

.SS sshd
SSHD can expose information and administrative function via ssh

.IP enabled
If true, this enables SSHD administration

.IP listen
Host and port to listen on. (Port 22 is not allowed.)

.IP host_key
A file containing a list of authorized public keys

.IP authorized_users
A list of users each with an array of keys

.SS tun

.IP disabled
When tun is disabled, a lighthouse can be started without a local run interface (and therefore without root)

.IP dev
The name of the device

.IP drop_local_broadcast
Toggles forwarding of local broadcast packets, the address of which depends on the ip/mask encoded in the pki.cert

.IP drop_multicast
Drop the forwarding of multicast packets

.IP tx_queue
Sets the transmit queue length. (If you notice lots of transmit drops on the tun it may help to raise this number. Defaults to 500.

.IP mtu
Default MTU for every packet, safe setting is (and the default) 1300 for internet based traffic.

.IP unsafe_routes
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.

.SS logging
Configure logging

.IP level
Configure the logging level. Must be one of panic, fatal, error, warning, info, or debug.

.IP format
Either json or text

.IP disable_timestamp
Disables timestamp logging. Useful when redirected into to a logging system which appends a time stamp. Defaults to false.

.SS stats
Enable a statistics exporter.

.IP type
Type of statistics exporter. Either "prometheus" or "graphite"

.IP interval
Interval to provide updates for either graphite or prometheus.

.IP prefix
Prefix for graphite

.IP protocol
Protocol for graphite

.IP host
Listener for graphite

.IP listen
IP and port to bind the prometheus listener

.IP path
Path on which metrics are supplied in prometheus

.IP namespace
Prometheus namespace

.IP subsystem
Prometheus subsystem

.IP message_metrics
Enables counter metrics for meta packets. (e.g. message.tx.handshake)

.IP lighthouse_metrics
Enables detailed counter metrics for lighthouse packets (e.g. lighthouse.rx.HostQuery)

.SS handshakes
Handshakes are sent to all known addresses at each interval with a linear back off.

.IP try_interval
Nebula waits try_interval after the first attempt, 2 * try_interval on the second attempt, until the handshake is older than timeout. This allows you to control this interval.

.IP retries
Number of retries before timing out

.IP trigger_buffer
Size of the buffer channel for quickly sending handshakes after receiving the response for lighthouse queries

.SS firewall
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)

.IP outbound
Section containing rules which apply to traffic send from this node. See the rules section.

.IP inbound
Section containing rules which apply to traffic send to this node from other hosts. See the rules section.

.SS rules
Rules are written in the outbound and inbound sections described above.

.IP proto
  Protocol. One of "any", "tcp", "udp", or "icmp"

.IP host
  "any" or literal hostname

.IP group
  "any" or literal group name

.IP groups
  Same as group but accepts a list of values. Certificate has to contain all groups to pass.

.IP cidr
  a CIDR, "0.0.0.0/0" is any

.IP ca_name
  An issuing CA name
.IP ca_sum
  An issuing CA shasum

.SH EXAMPLES

.P
There is a example configuration file in the FILES section below.

.P
Configuration files placed in /etc/nebula can take advantage of the built-in systemd templates. For example, if you have a nebula configuration /etc/nebula/office.yml

  [#] systemctl enable nebula@office.service

.SH FILES

.IP /etc/nebula
Contains configuration files for nebula(1). This provides a designated place to store configuration data and credentials. Configuration files placed in this directory can take advantage of the provided systemd template unit.

.IP /usr/share/doc/nebula/examples/config.yml
See this example configuration file.

.SH SEE ALSO
  nebula(1), nebula-cert(1)