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Cloud-Init User Data with Flight Solo

User data (otherwise known as "cloud-init data" or "cloud data") is a way of giving data to an instance for it to run as part of the startup process. This page will describe how to provide user data specific to Flight Solo to customise and configure your cluster.

When present, the file /opt/flight/ will be read and used to configure the Flight Solo image on first boot. The best way of creating this file on boot is by creating it with user data and providing the desired configuration keys to be written to the file.

The cloud-init write_files directive is used to create the file which is read in. A basic user data script that creates this file would look like:

Minimal Cloud Config Script
  - content: |
      OPTION="value" # (1)!
    path: /opt/flight/
    permissions: '0600'
    owner: root:root

  1. Replace OPTION with a config option described below

Flight Solo Config Options

The available options for the Flight Solo cloud-init file are as follows.


Sets the target address that Flight Hunter on the node will send to at startup. It is recommended that this is the local IP of whichever server is going to be used to manage the inventory of hosts.

Example Usage


Set the broadcast address which Flight Hunter will send to.

Example Usage


Sets the auth key that is used by Flight Hunter, this is used by both the hunt process and send command. Use this to secure your hunter inventory by only allowing hosts to push their information to it with a matching key.

Example Usage


Sets label to be used for the node in Flight Hunter.

Example Usage


Sets the prefix to be used for the node in Flight Hunter.

Example Usage


This option is superseded by LABEL if both are provided


Sets the regex for auto-parse rules in the Flight Hunter server.

Example Usage 1 - Match any incoming hostnames including 'example-domain'
Example Usage 2 - Parse all hosts that make it into the buffer


If set then this node will share the root user's pub ssh key over the local network on port 1234. This means that any solo images with SERVER set to this node will attempt to grab its public key to allow root SSH between your cluster.

Example Usage


Set to json text which is used to answer profile configure questions, the format should be the same as for the profile configure sub-option --answers. Any answers not supplied will be set to their default values.

Example Usage
PROFILE_ANSWERS='{ "cluster_type": "openflight-slurm-standalone", "cluster_name": "mycluster1" }'


Set automatic application of identities to nodes. When a node connects with hunter, if it matches one of the regular expressions then the corresponding identity will be applied.

Example Usage - Match hunter labels containing 'node' and apply the 'compute' identity to them, match hunter labels with 'gateway' in them and apply 'login' identity
AUTOAPPLY="node: compute, gateway: login"


AUTOAPPLY can only start if a cluster type has already been configured on this node. The configuration of the Flight Profile can be done before launching client nodes or set with PROFILE_ANSWERS.


Set prefix start numbers based on node name. When a node connects with hunter, if it has a prefix which matches one of the regular expressions then it will be given a number, starting with the start number and incrementing until there is an unused number.

Example Usage - Increment counts for 'node' from '001' and 'gpu' from '01'
PREFIX_STARTS="node: '001', gpu: '01'"


Many of these relate to command line options that are explained in more detail in the Flight Hunter documentation.


If set then this will set automatic removal of nodes from hunter and profile upon shutdown. This is especially beneficial for auto-scaling scenarios where a node shutting down usually means the resource is being destroyed and therefore tidying it from the cluster environment is required.

Example Usage