Self-Hosted PaaS on a VPS: What to Check Before Installing Coolify, Dokploy, or CapRover

Start with the server size

A self-hosted PaaS runs the platform itself plus your applications, databases, reverse proxy, build process, logs, and backups. A server that is fine for one static website may struggle with multiple containers.

Before installation, estimate RAM, CPU, disk, and bandwidth needs. Leave headroom for builds, updates, and temporary spikes.

Prepare DNS correctly

Most self-hosted PaaS platforms depend heavily on DNS. You may need a dashboard subdomain, app subdomains, wildcard records, or separate records for staging and production.

Decide where DNS is managed before installation. Editing records in the wrong DNS provider is one of the most common causes of failed deployments.

• Confirm active nameservers.
• Create a dashboard subdomain.
• Plan app subdomains.
• Decide whether wildcard DNS is needed.
• Document all DNS records before changing them.

Check ports and firewall rules

A deployment platform usually needs ports 80 and 443 for web traffic, plus SSH for administration. Some tools may use additional internal ports, but those should not automatically be public.

Review firewall rules and cloud provider security groups before assuming the application is broken.

Plan SSL before deploying apps

Self-hosted PaaS tools often automate SSL, but automation still depends on correct DNS and reachable HTTP or DNS validation. If SSL fails, the problem is often outside the app.

Make sure domains resolve to the VPS and that no conflicting reverse proxy is already using ports 80 or 443.

Decide where databases live

Running databases on the same VPS is convenient, but it increases the importance of backups and resource monitoring. For production workloads, consider whether managed databases or a separate database server are more appropriate.

If you keep databases on the same VPS, do not expose database ports publicly and test restore procedures early.

Set up backups before the first real deployment

Backups are often added after something goes wrong. That is backwards. A self-hosted PaaS should have backups for application data, databases, environment variables, and platform configuration.

A backup that has never been restored is only a theory. Test at least one restore workflow before relying on it.

Monitor logs, disk, and renewals

Self-hosted platforms can generate logs quickly. Docker images, build cache, database files, and backups can fill disk space faster than expected.

Set up basic monitoring for disk usage, memory, CPU load, SSL expiry, and failed containers. Even simple alerts are better than discovering a full disk from a customer report.