Remote Provision

Planning: dapsman prod provision

What Prod Provision Does

dapsman prod provision creates a remote VM on an OpenStack provider and installs Docker on it, leaving it ready for prod deploy. It runs entirely from the toolkit container, which has OpenStack CLI tools and SSH keys.

Steps:

1. Sources the provider’s OpenRC file to authenticate with OpenStack
2. Sources the instance vars file (e.g. hosting/ramnode_openstack_instance_vars.sh) for image, flavor, network, etc.
3. Generates an SSH keypair in the toolkit if one doesn’t exist
4. Uploads the public key to OpenStack if not already registered
5. Runs scripts/openstack-create-instance.sh, which creates (or reuses) the server and assigns an IP
6. The instance boots with scripts/openstack-cloud-init.yaml as user-data, which installs Docker and performs initial server setup

The provision workflow is intentionally minimal — it gets Docker running and nothing else. Project-specific setup happens during prod deploy.

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cloud-init (scripts/openstack-cloud-init.yaml)

Cloud-init runs once on first boot. It currently:

• Installs Docker CE and Docker Compose plugin
• Enables Docker at boot
• Adds the ubuntu user to the docker group (when present)
• Creates a 2GB swapfile at /swapfile (if not already present) and adds it to /etc/fstab
• Sets vm.swappiness=10 via /etc/sysctl.d/99-daps.conf

Why swap

Small VPS instances (1-4GB RAM) running WordPress + MySQL + Redis have no memory headroom during active use (theme editing, plugin updates, etc.). Without swap, the Linux OOM killer terminates the largest process — typically mysqld — causing a database unavailability error to site visitors.

2GB swap is a fixed value (not proportional to RAM) because swap on a cloud VPS is slow — it’s a safety net to absorb memory spikes, not a performance resource. 2GB is sufficient for Daps’s target instance sizes. For larger instances (8GB+) swap is rarely needed anyway.

vm.swappiness=10 tells the kernel to strongly prefer keeping data in RAM and only use swap as a last resort, which is the right behavior for a server workload.

Idempotency

The swapfile step is guarded with if [[ ! -f /swapfile ]] so it’s a no-op if the file already exists. In practice cloud-init only runs once per instance so this guard is defensive rather than necessary.

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Existing Instances

The cloud-init changes only apply to newly provisioned instances. To add swap to an existing instance, SSH in and run:

fallocate -l 2G /swapfile
chmod 600 /swapfile
mkswap /swapfile
swapon /swapfile
echo '/swapfile none swap sw 0 0' >> /etc/fstab
echo 'vm.swappiness=10' > /etc/sysctl.d/99-daps.conf
sysctl -p /etc/sysctl.d/99-daps.conf