Builder — Automated Site Deploy System

Builder is a three-part system that automates the build and deployment of static Next.js sites when content is published in a CRM. The parts are: site structure and build scripts, a webhook listener, and CRM(Contentful) triggers.

Table of Contents

Diagram: High level arch diagram

Part 1: Site Structure and Build Scripts

Each site lives in its own directory under

/home/builder/sites/

/home/builder/sites/
├── siteA/
│   ├── rebuild.sh
│   └── (Next.js project files)
├── siteB/
│   ├── rebuild.sh
│   └── (Next.js project files)

Each site has a

rebuild.sh

Example —

/home/builder/sites/siteA/rebuild.sh

#!/bin/bash
set -e

SITE_DIR="/home/builder/sites/siteA"
WEB_ROOT="/var/www/siteA"

echo "[$(date)] Starting build for siteA..."

cd "$SITE_DIR"
npm run build

echo "[$(date)] Build complete. Copying output..."
rm -rf "$WEB_ROOT"/*
cp -r "$SITE_DIR/out/." "$WEB_ROOT/"

echo "[$(date)] Deploy complete."

Key points:

• set -e

  stops the script immediately if any command fails, preventing a broken build from being copied to the web root

• npm run build

  requires

  output: 'export'

  in

  next.config.js

  so Next.js writes static files to

  /out

• The web root is cleared before copying to avoid stale files from previous builds

next.config.js

const nextConfig = {
    output: 'export',
    // ... rest of config
};

Part 2: Webhook Listener

The webhook listener receives HTTP requests from Nginx and triggers the appropriate site's

rebuild.sh

Installing webhook

sudo apt install webhook

hooks.json

Each site gets its own hook entry in

/etc/webhook/hooks.json

[
  {
    "id": "deploy-siteA",
    "execute-command": "/home/builder/sites/siteA/rebuild.sh",
    "command-working-directory": "/home/builder/sites/siteA"
  },
  {
    "id": "deploy-siteB",
    "execute-command": "/home/builder/sites/siteB/rebuild.sh",
    "command-working-directory": "/home/builder/sites/siteB"
  }
]

Adding a new site means adding a new object to this array and creating the corresponding

rebuild.sh

Running webhook as a service

Create a systemd service so webhook starts on boot and restarts on failure:

/etc/systemd/system/webhook.service

[Unit]
Description=Webhook listener
After=network.target

[Service]
User=builder
ExecStart=/usr/bin/webhook -hooks /etc/webhook/hooks.json -port 9000 -verbose
Restart=always

[Install]
WantedBy=multi-user.target

Enable and start it:

sudo systemctl enable webhook
sudo systemctl start webhook
sudo systemctl status webhook

Nginx configuration

Nginx exposes a single secret base path and routes each site's deploy to its corresponding webhook hook ID. The secret in the URL means the endpoints are not guessable:

location /hooks/YOUR-SECRET-HERE/deploy-siteA {
    proxy_pass http://127.0.0.1:9000/hooks/deploy-siteA;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
}

location /hooks/YOUR-SECRET-HERE/deploy-siteB {
    proxy_pass http://127.0.0.1:9000/hooks/deploy-siteB;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
}

The full public URLs become:

https://yourdomain.com/hooks/YOUR-SECRET-HERE/deploy-siteA
https://yourdomain.com/hooks/YOUR-SECRET-HERE/deploy-siteB

These are the URLs that Contentful will call in Part 3.

Testing a hook manually

curl -X POST https://yourdomain.com/hooks/YOUR-SECRET-HERE/deploy-siteA

Check the webhook logs to confirm it fired:

sudo journalctl -u webhook -f

Part 3: Contentful Webhook Triggers

Contentful can call a URL whenever content is published. Each site gets its own webhook in Contentful pointing to its deploy URL.

Setting up a webhook in Contentful

1. Go to Settings → Webhooks in your Contentful space
2. Click Add Webhook
3. Configure as follows:

Deploy siteA

https://yourdomain.com/hooks/YOUR-SECRET-HERE/deploy-siteA

POST

1. Repeat for each site, pointing each webhook at its own deploy URL

Trigger filter (recommended)

If multiple sites share the same Contentful space, you can add a filter so siteA only rebuilds when its own content is published, not every time anything is published in the space. Under Filters in the Contentful webhook config, add a condition such as:

Content type  equals  siteAPageType

This prevents unnecessary rebuilds when unrelated content is updated.

Full flow when an editor clicks Publish

Adding a new site

1. Create the site directory:

   mkdir /home/builder/sites/siteC

2. Add

   rebuild.sh

   with the correct paths
3. Add a new hook entry to

   /etc/webhook/hooks.json

4. Reload webhook:

   sudo systemctl restart webhook

5. Add a new

   location

   block to the Nginx config and reload Nginx
6. Add a new webhook in Contentful pointing to the new URL