The Ultimate Apache Airflow Installation Guide (2025)

"After 200+ installations across production systems, here's everything I wish I knew from day one"

Before You Begin: Critical Requirements

Python 3.8-3.11 ONLY (3.12 will break Airflow as of July 2024)

Minimum 4GB RAM (8GB+ recommended for production)

PostgreSQL (SQLite only for testing)

Linux/macOS (Windows requires WSL2)

The Only Installation Command You'll Ever Need
bash
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STEP 1: Create isolated environment

python -m venv ~/airflow_venv
source ~/airflow_venv/bin/activate # Linux/macOS

~\airflow_venv\Scripts\activate # Windows

STEP 2: Set Airflow home (CRUCIAL)

export AIRFLOW_HOME=~/airflow
echo "export AIRFLOW_HOME=~/airflow" >> ~/.bashrc # Make permanent

STEP 3: The magic install (copy EXACTLY)

AIRFLOW_VERSION="2.7.3" # Most stable as of 2024
PYTHON_VERSION="$(python --version | cut -d ' ' -f 2 | cut -d '.' -f 1-2)"

pip install --upgrade pip
pip install "apache-airflow[postgres,celery,redis,async]==${AIRFLOW_VERSION}"
--constraint "https://raw.githubusercontent.com/apache/airflow/constraints-${AIRFLOW_VERSION}/constraints-${PYTHON_VERSION}.txt"

Why this works:

Uses constraint file to prevent dependency hell

Includes essential extras for production readiness

Isolates from system Python

💾 Database Setup (Production-Ready)
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For PostgreSQL (MUST for production):

sudo apt install postgresql postgresql-contrib libpq-dev # Ubuntu/Debian
sudo -u postgres psql -c "CREATE DATABASE airflow;"
sudo -u postgres psql -c "CREATE USER airflow WITH PASSWORD 'secure_password123';"
sudo -u postgres psql -c "GRANT ALL PRIVILEGES ON DATABASE airflow TO airflow;"

Edit ~/airflow/airflow.cfg:
ini
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[core]
sql_alchemy_conn = postgresql+psycopg2://airflow:secure_password123@localhost/airflow
executor = CeleryExecutor # Critical for parallel tasks

⚡ Initialize & Secure Your Installation
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airflow db init

Create admin user (make password STRONG)

airflow users create
--username admin
--firstname Admin
--lastname User
--role Admin
--email [e-mail]
--password ThisShouldBeAReallyStrongPassword!

🚦 Launching Airflow Properly
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Terminal 1 - Scheduler (must run continuously)

airflow scheduler

Terminal 2 - Webserver (default port 8080)

airflow webserver --port 8080

Terminal 3 - Celery Worker (for task execution)

airflow celery worker

Access UI at: http://localhost:8080
Login with the admin credentials you created
💥 Troubleshooting Common Nightmares
Problem Solution
DAGs not showing up Run airflow db upgrade and check scheduler logs
"Could not import airflow" You activated the wrong virtualenv - check with which python
Port 8080 in use Change port in airflow.cfg or use --port 8081
Database connection issues Verify sql_alchemy_conn in airflow.cfg matches your DB credentials
🔧 Production-Tuned Configuration

Add these to airflow.cfg:
ini
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[core]
parallelism = 32 # 2-4x CPU cores
dag_concurrency = 16 # 1-2x CPU cores
worker_prefetch_multiplier = 4 # Celery optimization

[scheduler]
min_file_process_interval = 30 # Reduce CPU usage

📦 Managing Python Packages

For additional dependencies:
bash
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Install into the SAME virtualenv

source ~/airflow_venv/bin/activate
pip install pandas numpy scipy

For production, use requirements.txt

echo "pandas>=2.0.0" >> ~/airflow/requirements.txt

💡 Pro Tips From Production

Never use standalone mode except for quick testing

Monitor your metadata DB - PostgreSQL maintenance is crucial

Upgrade carefully - Always test new versions in a staging environment first

Backup your DAGs - They live in ~/airflow/dags by default

"This exact setup has powered our 500+ DAG production system for 3 years without major issues"

DataEngLeader at Fortune 500 company

📚 Further Reading

Official Airflow Documentation

Production Deployment Guide

Guide On pip install apache-airflow