cloud-init.yml — cloud-init user-data template for automated VM provisioning on OpenStack, Proxmox, or any cloud with cloud-init support
setup-host.sh — interactive post-install script for VMs that weren't provisioned with cloud-init
setup-openstack-secgroup.sh — creates an OpenStack security group with the right rules (SSH, mosh, ICMP)

Supported distributions

Debian 13 (Trixie) — recommended (matches opencode-devbox base image)
Ubuntu 24.04 LTS — also works

Other distributions will need manual adaptation.

Quick start

Option 1: Cloud-init (automated)

Customize cloud-init.yml — replace the SSH public key and optionally the hostname/timezone. Then use it during VM creation:

Proxmox: attach as cloud-init user-data
OpenStack: pass via --user-data flag (see full example below)
AWS/DigitalOcean/etc: paste into the "user data" field

Full OpenStack example

Cloud-init only handles guest configuration — flavor, image, network, and security group must be specified explicitly at creation time:

# List available flavors to choose appropriate sizing
openstack flavor list

# Create the security group first (one-time, see below)
./setup-openstack-secgroup.sh

# Basic — boot from default storage
openstack server create \
  --flavor c4m8 \
  --image debian-13-trixie \
  --network my-network \
  --security-group opencode-devbox \
  --key-name my-ssh-key \
  --user-data cloud-init.yml \
  devbox-vm

If your cloud offers NVMe-backed (performance) volumes, boot from one for faster Docker and build I/O:

# Performance — boot from NVMe volume (40GB, preserved on instance deletion)
openstack server create \
  --flavor c4m8 \
  --network my-network \
  --security-group opencode-devbox \
  --key-name my-ssh-key \
  --user-data cloud-init.yml \
  --block-device source=image,id=$(openstack image show debian-13-trixie -f value -c id),dest=volume,size=40,shutdown=preserve,bootindex=0,volume_type=performance \
  devbox-vm

The VM boots with Docker installed, firewall configured (or skipped on OpenStack), and your SSH key authorized. Log in as the devbox user.

Console password (optional)

The cloud-init template uses SSH key authentication only — no password is set by default. This is sufficient for normal use since the devbox user has passwordless sudo.

A password is only needed for:

Emergency console access — logging in via OpenStack Horizon console (noVNC) or Proxmox VNC when SSH is unreachable
su - devbox — switching to the devbox user from another account

To enable console access, uncomment the chpasswd block in cloud-init.yml before deploying:

chpasswd:
  expire: false
  users:
    - name: devbox
      password: your-password-here
      type: text

For an already-running VM, set a password via SSH:

sudo passwd devbox

Option 2: Post-install script (manual)

On a fresh Debian/Ubuntu VM:

curl -fsSL https://gitea.jordbo.se/joakimp/opencode-devbox/raw/branch/main/deploy/setup-host.sh | bash

Or clone and run:

git clone https://gitea.jordbo.se/joakimp/opencode-devbox
cd opencode-devbox/deploy
./setup-host.sh

What gets installed

Docker Engine (from Docker's official apt repo, not distro's docker.io)
Docker Compose plugin (v2)
tmux, mosh, git
ufw firewall with SSH (22) and mosh (UDP 60000-61000) allowed — skipped on OpenStack (detected automatically; use security groups instead)
IPv4 DNS preference (works around Docker Hub IPv6 connectivity issues)

OpenStack security groups

On OpenStack, firewalling is handled by security groups rather than ufw. The setup-host.sh script detects OpenStack automatically and skips ufw configuration.

To create the required security group:

./setup-openstack-secgroup.sh

This creates a security group named opencode-devbox with rules for SSH (TCP 22), mosh (UDP 60000-61000), and ICMP. Apply it to your instance:

# New instance
openstack server create --security-group opencode-devbox ...

# Existing instance
openstack server add security group <instance-name> opencode-devbox

VM sizing recommendations

Use case	vCPU	RAM	Disk
Minimum	2	4 GB	20 GB
Recommended	4	8 GB	40 GB
Heavy use (Rust/Python builds, multi-project)	8	16 GB	80 GB

After VM setup

mkdir -p ~/opencode-devbox && cd ~/opencode-devbox
curl -sL https://gitea.jordbo.se/joakimp/opencode-devbox/raw/branch/main/docker-compose.yml -o docker-compose.yml
curl -sL https://gitea.jordbo.se/joakimp/opencode-devbox/raw/branch/main/.env.example -o .env
vim .env                                           # configure provider and keys
docker compose up -d
docker compose exec -u developer devbox opencode