Ubuntu Production Deployment Guide (LXC on Proxmox)

Environment: Ubuntu 24.04 LXC | Residential ISP

Stack: React + Kotlin Micronaut + PostgreSQL

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1. LXC Provisioning (Proxmox Host)

Run these on your Proxmox Host to create the containers using Ubuntu 24.04:

# Update templates and download Ubuntu 24.04
pveam update
pveam download local ubuntu-24.04-standard_24.04-1_amd64.tar.zst

# Database (2GB RAM, 16GB Disk)
pct create 200 local:vztmpl/ubuntu-24.04-standard_24.04-1_amd64.tar.zst --hostname pg-db --memory 2048 --net0 name=eth0,bridge=vmbr0,ip=dhcp --rootfs local:16 --unprivileged 1
# Backend (2GB RAM, 10GB Disk)
pct create 201 local:vztmpl/ubuntu-24.04-standard_24.04-1_amd64.tar.zst --hostname kt-backend --memory 2048 --net0 name=eth0,bridge=vmbr0,ip=dhcp --rootfs local:10 --unprivileged 1
# Frontend/Nginx (1GB RAM, 8GB Disk)
pct create 202 local:vztmpl/ubuntu-24.04-standard_24.04-1_amd64.tar.zst --hostname react-frontend --memory 1024 --net0 name=eth0,bridge=vmbr0,ip=dhcp --rootfs local:8 --unprivileged 1
# Cloudflare Tunnel (512MB RAM, 2GB Disk)
pct create 203 local:vztmpl/ubuntu-24.04-standard_24.04-1_amd64.tar.zst --hostname cf-tunnel --memory 512 --net0 name=eth0,bridge=vmbr0,ip=dhcp --rootfs local:2 --unprivileged 1

# Start all
pct start 200 && pct start 201 && pct start 202 && pct start 203

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2. Configuration by Container

Database (LXC 200 - Ubuntu)

pct enter 200
apt update && apt install -y postgresql
# Allow connections from Backend (LXC 201)
echo "listen_addresses = '*'" >> /etc/postgresql/16/main/postgresql.conf
echo "host all all 192.168.1.0/24 md5" >> /etc/postgresql/16/main/pg_hba.conf
systemctl restart postgresql

Backend: Kotlin Micronaut (LXC 201 - Ubuntu)

pct enter 201
# Install Java 17/21
apt update && apt install -y openjdk-21-jre-headless
# Deploy Micronaut JAR
# (Copy your .jar file via 'pct push 201 myapp.jar /opt/myapp.jar')
# Run as systemd service

Frontend: React + Nginx (LXC 202 - Ubuntu)

pct enter 202
apt update && apt install -y nginx
# Copy build artifacts to /var/www/html
# Update /etc/nginx/sites-available/default to handle React routing and proxy /api

location / {
    try_files $uri /index.html;
}

location /api/ {
    proxy_pass http://192.168.1.201:8080/; # Point to Backend LXC
}

Cloudflare Tunnel (LXC 203 - Ubuntu)

pct enter 203
apt update && apt install -y curl
curl -L --output cloudflared.deb https://github.com/cloudflare/cloudflared/releases/latest/download/cloudflared-linux-amd64.deb
dpkg -i cloudflared.deb
# Authenticate and run:
cloudflared tunnel run --token YOUR_TOKEN

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3. Connectivity Matrix

Service	Hostname	Internal IP	External Route
PostgreSQL	pg-db	192.168.1.200	None (Internal Only)
Micronaut	kt-backend	192.168.1.201	None (Proxied by Nginx)
React	react-frontend	192.168.1.202	Proxied by Cloudflare
CF Tunnel	cf-tunnel	192.168.1.203	Outbound Gateway

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4. Production Hardening

• Static IPs: Assign static IPs to LXCs in Proxmox Dashboard for reliable communication between services.
• Fail2Ban: Install on the Nginx LXC.
• Backups: Use Proxmox Snapshots and pg_dump to an external NFS share.