🧪 PostgreSQL + MinIO Measurement Database (Nix Flake)

A reproducible development environment providing a PostgreSQL measurement database with MinIO object storage, designed for local experiments and data-driven workflows.

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Overview

This flake sets up:

• 🐘 PostgreSQL 15 — local database instance for structured measurement data
• 🪣 MinIO — lightweight, S3-compatible object storage
• 🧩 Automatic initialization of postgresql.conf and pg_hba.conf from external files
• 💾 Persistent local data directories under ./data/

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🧱 Directory Structure

arbok_database/
├── flake.nix
├── config/
│   ├── postgresql.conf       # Custom PostgreSQL configuration template
│   └── pg_hba.conf           # Host-based authentication config
├── data/                     # Created automatically by shellHook
│   ├── pgdata/               # PostgreSQL data directory (after initdb)
│   ├── pgsock/               # UNIX socket directory for PostgreSQL
│   └── minio/                # MinIO data storage root
└── minio.log                 # Runtime log written when MinIO starts

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⚙️ Getting Started

1️⃣ Enter the dev shell

nix develop

### Start/Stop PostgreSQL
pg_ctl -D "$PGDATA" -o "-k $PGSOCKET" -l logfile start
pg_ctl -D "$PGDATA" -o "-k $PGSOCKET" stopi

Start/Stop MinIO

MinIO starts automatically when entering the shell. You can stop it manually using:

stopminio

Connect via SQLAlchemy

Example pythin connection using TCP:

from sqlalchemy import create_engine

engine = create_engine("postgresql+psycopg2://localhost:5432/postgres")

or via Unix socket:

socket_dir = "/path/to/data/pgsock"
engine = create_engine(f"postgresql+psycopg2:///postgres?host={socket_dir}")

Tips

• Data is stored under ./data, so you can safely rebuild or re-enter the flake shell withoutloosing data
• Logs are written to data/mini.log
• The configuration files (postgresql.conf and pg_hba.conf`) can be customized outside the flake and are imported and configured automatically