Cloud-Init Configuration

Final cloud-init Used

This is the production cloud-init applied during node deployment:

#cloud-config

hostname: needed-lion

package_update: true
package_upgrade: true

packages:
  - curl
  - vim
  - htop
  - net-tools
  - ca-certificates

write_files:
  - path: /etc/sysctl.d/99-disable-ipv6.conf
    content: |
      net.ipv6.conf.all.disable_ipv6=1
      net.ipv6.conf.default.disable_ipv6=1
      net.ipv6.conf.lo.disable_ipv6=1

runcmd:
  - sysctl --system
  - timedatectl set-timezone UTC

final_message: "Node ready 🚀"

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What Each Section Does

Section	Purpose
hostname	Sets the node hostname
package_update / package_upgrade	Ensures OS is fully updated
packages	Installs essential tools
write_files	Creates sysctl config to disable IPv6
runcmd	Applies sysctl settings, sets timezone

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Critical Warning

:::danger Do NOT add a users block

# ❌ NEVER do this with MAAS
users:
  - name: ubuntu
    ...

MAAS automatically injects the SSH public key you configured in your profile. If you define a users block in cloud-init, it overrides MAAS's key injection and you will be locked out (SSH Permission Denied).

✔ Remove the users block entirely — MAAS handles it. :::

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Adapting for Each Node

Change the hostname field per node:

# set-hog
hostname: set-hog

# fast-skunk
hostname: fast-skunk

# fast-heron
hostname: fast-heron

All other settings remain identical across nodes.