PostgreSQL Through SSH

Quick Guide: Python → PostgreSQL Through SSH

1. Architecture

Your setup is:

Windows PC
    │
    ▼
WSL2
    │
    │ SSH tunnel
    │ localhost:15432
    ▼
Ubuntu laptop
    │
    │ localhost:5432
    ▼
PostgreSQL 18.6
    │
    ▼
tompkins database

The important point:

• PostgreSQL port: 5432
• SSH tunnel port in WSL2: 15432
• 15432 is only the local endpoint of the tunnel.

---

2. Verify PostgreSQL on Ubuntu

On Ubuntu:

sudo -u postgres psql -c "SHOW port;"

Expected:

5432

PostgreSQL is listening on:

127.0.0.1:5432

---

3. Create the SSH tunnel

From WSL2:

ssh -L 15432:127.0.0.1:5432 admin@192.168.1.65

Keep this terminal open.

The syntax is:

-L LOCAL_PORT:REMOTE_HOST:REMOTE_PORT

So:

15432:127.0.0.1:5432
  │        │          │
  │        │          └── PostgreSQL on Ubuntu
  │        └───────────── Ubuntu's localhost
  └────────────────────── WSL2 local port

---

4. Test the tunnel with psql

Open a second WSL2 terminal:

psql -h 127.0.0.1 -p 15432 -U postgres -d tompkins

Then:

SELECT version();

You successfully tested this with:

PostgreSQL 18.6

Exit:

\q

---

5. Set up Python

In WSL2:

mkdir -p ~/python-postgres
cd ~/python-postgres

python3 -m venv .venv
source .venv/bin/activate

pip install psycopg2-binary

---

6. Python connection

test_connection.py:

import psycopg2

conn = psycopg2.connect(
    host="127.0.0.1",
    port=15432,
    dbname="tompkins",
    user="postgres",
    password="YOUR_PASSWORD"
)

print("Connected to PostgreSQL!")

cur = conn.cursor()

cur.execute("SELECT version();")

result = cur.fetchone()

print(result[0])

cur.close()
conn.close()

Run:

python3 test_connection.py

You successfully obtained:

Connected to PostgreSQL!
PostgreSQL 18.6 ...

---

7. What is happening?

Python connects to:

127.0.0.1:15432

SSH forwards that connection to:

Ubuntu 127.0.0.1:5432

PostgreSQL receives it normally.

So Python does not directly connect to:

192.168.1.65:5432

and PostgreSQL does not need to be exposed to the network.

---

8. Do you need to create the tunnel every time?

With the manual approach, yes.

Every time you need the connection:

ssh -L 15432:127.0.0.1:5432 admin@192.168.1.65

Then run Python in another terminal.

You can later simplify this with SSH configuration or background tunnels.

Current workflow

Terminal 1 — WSL2
ssh -L 15432:127.0.0.1:5432 admin@192.168.1.65


Terminal 2 — WSL2
cd ~/python-postgres
source .venv/bin/activate
python3 test_connection.py

This is the fundamental Python → SSH tunnel → remote PostgreSQL pattern.