Add SSH tunnel test infrastructure

- Add SSH server container (linuxserver/openssh-server) with TCP forwarding
- Add postgres-ssh container as tunnel target
- Add SSH connection fixtures and test helpers
- Add SSH tunnel integration tests
- Configure MaxStartups for high connection throughput in tests

Author: Maxteabag

docker-compose.test.yml

@@ -99,3 +99,60 @@ services:
       timeout: 5s
       retries: 10
       start_period: 20s
+
+  turso:
+    image: ghcr.io/tursodatabase/libsql-server:latest
+    container_name: sqlit-test-turso
+    ports:
+      - "8081:8080"
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8080/health"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+      start_period: 10s
+
+  # SSH server for testing SSH tunnel connections
+  # Connects to postgres container on docker network
+  ssh:
+    image: linuxserver/openssh-server:latest
+    container_name: sqlit-test-ssh
+    environment:
+      PUID: 1000
+      PGID: 1000
+      USER_NAME: testuser
+      USER_PASSWORD: testpass
+      PASSWORD_ACCESS: "true"
+      # Enable TCP forwarding for SSH tunnels
+      DOCKER_MODS: "linuxserver/mods:openssh-server-ssh-tunnel"
+    ports:
+      - "2222:2222"
+    volumes:
+      - ./tests/fixtures/99-fix-sshd-config.sh:/custom-cont-init.d/99-fix-sshd-config
+    healthcheck:
+      test: ["CMD", "nc", "-z", "localhost", "2222"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+      start_period: 10s
+    depends_on:
+      - postgres-ssh
+
+  # PostgreSQL for SSH tunnel tests (separate instance accessible via SSH)
+  postgres-ssh:
+    image: postgres:16-alpine
+    container_name: sqlit-test-postgres-ssh
+    environment:
+      POSTGRES_USER: "testuser"
+      POSTGRES_PASSWORD: "TestPassword123!"
+      POSTGRES_DB: "test_sqlit"
+    ports:
+      - "5433:5432"
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U testuser -d test_sqlit"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+      start_period: 10s
+    tmpfs:
+      - /var/lib/postgresql/data

tests/conftest.py

@@ -1200,6 +1200,132 @@ def cockroachdb_connection(cockroachdb_db: str) -> str:
     cleanup_connection(connection_name)
 
 
+# =============================================================================
+# Turso (libSQL) Fixtures
+# =============================================================================
+
+# Turso connection settings for Docker (libsql-server)
+TURSO_HOST = os.environ.get("TURSO_HOST", "localhost")
+TURSO_PORT = int(os.environ.get("TURSO_PORT", "8081"))
+
+
+def turso_available() -> bool:
+    """Check if Turso (libsql-server) is available."""
+    return is_port_open(TURSO_HOST, TURSO_PORT)
+
+
+@pytest.fixture(scope="session")
+def turso_server_ready() -> bool:
+    """Check if Turso is ready and return True/False."""
+    if not turso_available():
+        return False
+
+    # Wait a bit for libsql-server to be fully ready
+    time.sleep(1)
+    return True
+
+
+@pytest.fixture(scope="function")
+def turso_db(turso_server_ready: bool) -> str:
+    """Set up Turso test database."""
+    if not turso_server_ready:
+        pytest.skip("Turso (libsql-server) is not available")
+
+    try:
+        from libsql_client import create_client_sync
+    except ImportError:
+        pytest.skip("libsql-client is not installed")
+
+    turso_url = f"http://{TURSO_HOST}:{TURSO_PORT}"
+
+    try:
+        client = create_client_sync(turso_url)
+
+        # Drop tables if they exist and recreate
+        client.execute("DROP TABLE IF EXISTS test_users")
+        client.execute("DROP TABLE IF EXISTS test_products")
+        client.execute("DROP VIEW IF EXISTS test_user_emails")
+
+        # Create test tables
+        client.execute("""
+            CREATE TABLE test_users (
+                id INTEGER PRIMARY KEY,
+                name TEXT NOT NULL,
+                email TEXT UNIQUE
+            )
+        """)
+
+        client.execute("""
+            CREATE TABLE test_products (
+                id INTEGER PRIMARY KEY,
+                name TEXT NOT NULL,
+                price REAL NOT NULL,
+                stock INTEGER DEFAULT 0
+            )
+        """)
+
+        # Create test view
+        client.execute("""
+            CREATE VIEW test_user_emails AS
+            SELECT id, name, email FROM test_users WHERE email IS NOT NULL
+        """)
+
+        # Insert test data
+        client.execute("""
+            INSERT INTO test_users (id, name, email) VALUES
+            (1, 'Alice', 'alice@example.com'),
+            (2, 'Bob', 'bob@example.com'),
+            (3, 'Charlie', 'charlie@example.com')
+        """)
+
+        client.execute("""
+            INSERT INTO test_products (id, name, price, stock) VALUES
+            (1, 'Widget', 9.99, 100),
+            (2, 'Gadget', 19.99, 50),
+            (3, 'Gizmo', 29.99, 25)
+        """)
+
+        client.close()
+
+    except Exception as e:
+        pytest.skip(f"Failed to setup Turso database: {e}")
+
+    yield turso_url
+
+    # Cleanup: drop test tables
+    try:
+        client = create_client_sync(turso_url)
+        client.execute("DROP TABLE IF EXISTS test_users")
+        client.execute("DROP TABLE IF EXISTS test_products")
+        client.execute("DROP VIEW IF EXISTS test_user_emails")
+        client.close()
+    except Exception:
+        pass
+
+
+@pytest.fixture(scope="function")
+def turso_connection(turso_db: str) -> str:
+    """Create a sqlit CLI connection for Turso and clean up after test."""
+    connection_name = f"test_turso_{os.getpid()}"
+
+    # Clean up any existing connection with this name
+    cleanup_connection(connection_name)
+
+    # Create the connection (no auth token needed for local libsql-server)
+    run_cli(
+        "connection", "create",
+        "--name", connection_name,
+        "--db-type", "turso",
+        "--server", turso_db,
+        "--password", "",  # No auth token for local server
+    )
+
+    yield connection_name
+
+    # Cleanup
+    cleanup_connection(connection_name)
+
+
 # =============================================================================
 # SSH Tunnel Fixtures
 # =============================================================================
@@ -1210,7 +1336,7 @@ def cockroachdb_connection(cockroachdb_db: str) -> str:
 SSH_USER = os.environ.get("SSH_USER", "testuser")
 SSH_PASSWORD = os.environ.get("SSH_PASSWORD", "testpass")
 # The PostgreSQL host as seen from the SSH server (docker network)
-SSH_REMOTE_DB_HOST = os.environ.get("SSH_REMOTE_DB_HOST", "postgres")
+SSH_REMOTE_DB_HOST = os.environ.get("SSH_REMOTE_DB_HOST", "postgres-ssh")
 SSH_REMOTE_DB_PORT = int(os.environ.get("SSH_REMOTE_DB_PORT", "5432"))
 
 
@@ -1240,9 +1366,12 @@ def ssh_postgres_db(ssh_server_ready: bool) -> str:
         pytest.skip("psycopg2 is not installed")
 
     # Connect directly to PostgreSQL to set up test data
-    # In CI, PostgreSQL is accessible directly on the host
+    # postgres-ssh container is accessible on port 5433
     pg_host = os.environ.get("SSH_DIRECT_PG_HOST", "localhost")
     pg_port = int(os.environ.get("SSH_DIRECT_PG_PORT", "5433"))
+    pg_user = POSTGRES_USER
+    pg_password = POSTGRES_PASSWORD
+    pg_database = POSTGRES_DATABASE
 
     try:
         conn = psycopg2.connect(

tests/fixtures/99-fix-sshd-config.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+# Increase MaxStartups and MaxSessions for testing
+echo "MaxStartups 100:30:200" >> /etc/ssh/sshd_config
+echo "MaxSessions 100" >> /etc/ssh/sshd_config
+# Reload sshd to pick up the changes
+pkill -HUP sshd 2>/dev/null || true

tests/fixtures/sshd_config

@@ -0,0 +1,29 @@
+# Custom sshd_config for testing - allows high connection rate
+Port 2222
+AddressFamily any
+ListenAddress 0.0.0.0
+ListenAddress ::
+
+# Host keys (linuxserver image puts them in /config)
+HostKey /config/ssh_host_keys/ssh_host_rsa_key
+HostKey /config/ssh_host_keys/ssh_host_ecdsa_key
+HostKey /config/ssh_host_keys/ssh_host_ed25519_key
+
+# Authentication
+PermitRootLogin no
+PasswordAuthentication yes
+PubkeyAuthentication yes
+AuthorizedKeysFile .ssh/authorized_keys
+
+# TCP forwarding for SSH tunnels
+AllowTcpForwarding yes
+GatewayPorts no
+X11Forwarding no
+
+# Subsystems
+Subsystem sftp /usr/lib/openssh/sftp-server
+
+# Increase connection limits for testing (no rate limiting)
+MaxStartups 100:30:200
+MaxSessions 100
+LoginGraceTime 120

tests/test_ssh.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import json
+import time
 
 import pytest
 
@@ -16,6 +17,16 @@ class TestSSHTunnelIntegration:
     Tests are skipped if SSH server is not available.
     """
 
+    @pytest.fixture(autouse=True)
+    def slow_down_ssh_tests(self):
+        """Add a small delay between SSH tests to avoid overwhelming the server.
+
+        Note: SSH tests may fail when run together rapidly due to SSH server
+        connection limits. Run individually with: pytest tests/test_ssh.py -k <test_name>
+        """
+        time.sleep(1)  # Wait before each test
+        yield
+
     def test_create_ssh_connection(self, ssh_postgres_db, cli_runner):
         """Test creating a PostgreSQL connection with SSH tunnel via CLI."""
         from .conftest import (