🛠️ Building a Production-Grade Home Cloud on Oracle's $0 Always Free Tier

What can you actually run on a $0/month Always Free cloud server?

In this post, I document the end-to-end journey of turning an Oracle Cloud 1 GB AMD Micro instance (amd10) in Tokyo into a multi-service personal cloud hub — complete with Dual-Stack DNS ad-blocking, Google Single Sign-On (SSO), lossless Hi-Res music streaming, a Rust-powered REST & AI MCP API, and a Hugo static blog.

🏗️ Architecture & Network Blueprint

graph TD
    Internet["🌐 Internet / Home Network / Mobile"] --> Caddy["🔒 Caddy (Auto Let's Encrypt SSL)"]
    
    subgraph OCI Cloud Instance (amd10 - Tokyo)
        Caddy -->|/| VietCal["📅 VietCalendar REST & MCP (Rust :8080)"]
        Caddy -->|files.*| Oauth["🔑 OAuth2-Proxy (Google SSO :4180)"]
        Oauth --> FileBrowser["📁 FileBrowser Cloud Drive (:8082)"]
        Caddy -->|music.*| Navidrome["🎵 Navidrome Lossless FLAC (:4533)"]
        Caddy -->|blog.*| Hugo["📝 Hugo Static Site (:443)"]
        Caddy -->|adguard.*| AdGuardWeb["🛡️ AdGuard Dashboard (:3000)"]
        
        Router["🏠 Home Router (Fiber IPv4 & IPv6)"] --> AdGuardDNS["🛡️ AdGuard DNS Server (:53 & :853 DoT)"]
    end

⚡ 1. Reclaiming Hardware RAM (The crashkernel Discovery)

On a standard 1 GB VM, Linux kdump can silently reserve up to 448 MB RAM (nearly half the server’s memory!).

By disabling crashkernel=no in GRUB:

• Reclaimed physical RAM from 512 MB → 946 MB.
• Added a 2.5 GB swap file with zram/swappiness tuning.
• Result: Plenty of headroom to run 6 concurrent services simultaneously.

🛡️ 2. Whole-Home Dual-Stack Ad-Blocking & Private DNS

We provisioned a dual-stack network with reserved static addresses:

• Public IPv4: 152.70.xxx.xxx (Always Free Reserved Static IP)
• Public IPv6: 2603:c021:8022:100::xxxx (Always Free /56 Prefix)
• Android / iOS Private DNS (DoT): <your-domain>.duckdns.org on Port 853 with automatic Let’s Encrypt TLS.
• Router DNS: Configured on our home fiber router, blocking ads and tracking telemetry across Smart TVs, iPhones, laptops, and IoT devices.

📅 3. VietCalendar: High-Performance Rust & AI MCP Server

Running on native Rust (Axum framework):

• Computes accurate Vietnamese Solar-to-Lunar conversions and public holiday schedules.
• Exposes an interactive Swagger OpenAPI UI at /swagger-ui/.
• Exposes a Universal Model Context Protocol (MCP) endpoint at /mcp/sse for AI assistants like Antigravity and Claude.
• RAM footprint: An astonishing < 1 MB RAM!

🎵 4. Navidrome: Bit-Perfect Lossless FLAC Streaming

• Deployed Navidrome in Go to stream Hi-Res 24-bit / 96kHz FLAC and ALAC audio.
• Full Subsonic API compatibility with audiophile mobile apps:
  • Android: Symfonium (bit-perfect USB DAC output).
  • iOS: Amperfy and play:Sub.
• RAM footprint: ~48 MB RAM.

📁 5. FileBrowser with Google Single Sign-On (SSO)

• Self-hosted cloud drive on the 38 GB free NVMe disk.
• Secured by OAuth2-Proxy: Whitelisted strictly to personal Google accounts. No passwords required — 1 click “Sign In with Google” logs you in directly.
• Seamless Synergy: Uploading audio files into the Music/ folder in FileBrowser automatically syncs them into Navidrome for streaming!
• Blog Synergy: Markdown posts created in the Blog/ folder auto-publish to this website!

📝 6. Hugo + PaperMod: Sub-Millisecond Static Tech Blog

• Static site generator built with Hugo and the PaperMod theme.
• Served directly by Caddy with gzip/zstd compression.
• 0 MB RAM runtime overhead and instant sub-second auto-rebuilding whenever a Markdown post is saved.

📊 Live Server Resource Breakdown (amd10)

All 6 services running concurrently on 1 single core and 1 GB RAM:

💻 Infrastructure as Code & Open Source

The complete automated provisioning runbook, security lists, and Terraform configurations are open-sourced on GitHub:

👉 https://github.com/vinhthang/oci

Written on and served from amd10 in Tokyo.