# SSH Tunneling
You can connect Postgres, MySQL, MSSQL, MongoDB, and other databases that are hosted under a private network via SSH tunnels.
Follow the instruction below to configure SSH tunneling in UI Bakery:
1. Start by navigating to the data source connection window - choose your data source and select the **Enable SSH tunnel** checkbox.
{% hint style="success" %}
For already connected data sources, you just need to open their settings.
{% endhint %}
2. Now, you need to configure your *bastion host* to allow UI Bakery to establish an SSH tunnel:
1. Create a **UI Bakery user** (UI Bakery will connect to your bastion as this user):
```bash
# Use this command if you use Amazon Linux
sudo adduser uibakery --password NP
# Use this command if you use any other Linux/Mac
sudo adduser uibakery --disabled-password
```
2. Next, create the required `authorized_keys` file and configure its permissions:
# Login as root user
sudo su
# Create the authorized_keys file if it does not exist
mkdir -p /home/uibakery/.ssh
touch /home/uibakery/.ssh/authorized_keys
# Set required permissions and make uibakery user an owner of this file
chmod 644 /home/uibakery/.ssh/authorized_keys
chown uibakery:uibakery /home/uibakery/.ssh/authorized_keys
3. Now, go back to the data source connection window, copy the **SSH public key**, and paste it to the `authorized_keys` file:
```bash
# Use any text editor and insert previously copied ssh public key in authorized_keys file
vim /home/uibakery/.ssh/authorized_keys
```
{% hint style="info" %}
The same steps apply for on-premise deployments as well.
{% endhint %}
3. Once connected, return to UI Bakery and specify your **bastion host** and **port number** under the *Enable SSH tunnel* checkbox.
{% hint style="info" %}
Usually, *bastion host* is either the domain or IP address of the virtual machine and *port number* is the SSH port (22) of the server that holds the database.
{% endhint %}
4. Next, specify the **Bastion user** you created in Step 2 (a).
5. Finally, scroll up to the *Connection settings* section and specify all the required fields.
:information\_source: Please note that in the **Host** field you either need to specify:
* *localhost* (if the bastion and database are on the same virtual machine) or
* your *private network IP address* (if bastion and database are on different virtual machines with mutual access and the 3306 port is open)
6. Click **Test connection** to check whether the data source can be connected, and then click **Connect Datasource**.
