cloud-init (the Ubuntu package for handling early initialization of cloud instances) can be used to provide additional flexibility when configuring Helion Stackato cluster nodes, and can simplify joining a cluster and assigning roles.
cloud-init can be configured at instance launch time via the
--user-data-file arguments to ec2-run-instances,
or by pasting YAML directly into the EC2 or OpenStack Horizon
For example, given a core node at IP 10.2.3.4, the following cloud-config would add a new DEA node to the cluster:
#cloud-config stackato: nats: ip: 10.2.3.4 roles: ['dea'] extname: "dea.example.com"
kato attach <nats ip>the first time the VM is booted.
extnamewhen supplied with a fully qualified domain name will run
kato rename <extname>on the instance first boot.
To lock down and secure this new node, you can use standard cloud-config directives for:
On EC2, it is also possible to use a well-known trick to resolve the public DNS name for an elastic IP to a local IP (within EC2). To use the DNS name rather than a specific local IP, your configuration changes slightly:
#cloud-config stackato: nats: elastic_dns: ec2-75-101-137-243.compute-1.amazonaws.com
This configuration will automatically obtain the local IP of whichever node is configured with the public IP 184.108.40.206 and use that when communicating over the message bus.
In addition to the Helion Stackato node configuration tasks described above, cloud-init can be used for a variety of system setup tasks: