In the following section you can find example configuration files to achieve specific c3os setups.
By default c3os requires multiple nodes. As for the c3os decentralized nature, it requires co-ordination between at least 2 nodes to achieve consensus on IPs, network setting, etc.
In order to create single-node cluster, we need to force both the role and the ip by disabling DHCP:
c3os:
network_token: "...."
role: "master"
vpn:
# EdgeVPN environment options
DHCP: "false"
ADDRESS: "10.1.0.2/24"
Note, the same setup can be used to specify master nodes in a set, as to join nodes it is still possible without specifying any extra setting:
c3os:
network_token: "...."
As always, IPs here are arbitrary as they are virtual ips in the VPN which is created between the cluster nodes.
c3os can be also used without any VPN and P2P network. Infact, k3s is already pre-installed, and it is sufficient to not specify any c3os block in the cloud init configuration.
For example, to start k3s as a server with c3os it’s sufficient to specify the k3s service in the config file:
#node-config
k3s:
enabled: true
And similarly for an agent:
#node-config
k3s-agent:
enabled: true
env:
K3S_TOKEN: ...
K3S_URL: ...
This is will setup k3s single-node + VPN with a static ip (10.1.0.2).
c3os:
network_token: "...."
role: "master"
vpn:
# EdgeVPN environment options
DHCP: "false"
ADDRESS: "10.1.0.2/24"
stages:
initramfs:
- name: "Set user and password"
users:
c3os:
passwd: "c3os"
Sometimes you might want to create a single cloud-init file for a set of machines, and also make sure each node has a different hostname.
The cloud-config syntax supports templating, so one could automate hostname generation based on the machine id which is generated for each host:
#node-config
stages:
initramfs:
- name: "Setup hostname"
hostname: "node-{{ trunc 4 .MachineID }}"