Update README and add deployment instructions

Author: pavlo-liapin

DEPLOYMENT.md

@@ -0,0 +1,111 @@
+## 1. Start a new droplet with the pre-installed Ruby
+
+* Navigate to the Digital Ocean dashboard and choose the appropriate project from the left menu.
+* Click on _Create > Droplets_ to initiate the setup process.
+
+![Screenshot 2024-02-16 at 11 22 56](https://github.com/vault12/zax/assets/1370944/b1dfd86f-63a5-49bb-939d-a2148bbe4a64)
+
+* Under _Choose an Image_, select _Marketplace_ and then opt for the _Ruby On Rails_ image. Ensure it's the appropriate version (e.g., Version 7.0.4.2, OS Ubuntu 22.04).
+
+![Screenshot 2024-02-16 at 11 24 53](https://github.com/vault12/zax/assets/1370944/5009c912-e256-4c48-8590-14572d98facf)
+
+* For authentication, choose the _SSH Key_ option and select your preferred SSH key.
+* Click _Create Droplet_ and patiently wait for the droplet to be provisioned.
+* You can find more details about the package on the [Ruby on Rails Droplet](https://marketplace.digitalocean.com/apps/ruby-on-rails) page.
+
+## 2. SSH into the Droplet
+
+Once the droplet is ready, access it via SSH using the following command:
+
+```bash
+ssh root@your_droplet_ip
+```
+
+Replace `your_droplet_ip` with the actual IP address of your newly created droplet.
+
+## 3. Install Redis
+
+Install Redis on the server by following the Digital Ocean guide [How To Install and Secure Redis on Ubuntu 20.04](https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-redis-on-ubuntu-20-04). Here are the summarized steps:
+
+* **Install Redis package**. Run `apt install redis-server`.
+* **Update Redis configuration**. Edit `/etc/redis/redis.conf` and set the `supervised` directive to `systemd`.
+* **Restart Redis service**. Run `systemctl restart redis.service` to apply the changes.
+
+## 4. Install and configure Zax
+
+* In the SSH console, sign in as the predefined **rails** user:
+
+```bash
+su - rails
+```
+
+* Clone [Zax repository](https://github.com/vault12/zax), navigate into the directory and run the script to install dependencies:
+
+```bash
+git clone https://github.com/vault12/zax.git
+cd zax
+./install_dependencies.sh
+```
+
+* Whitelist your hostname for production use
+
+By default, Rails 6 applications reject all requests that are not made to the configured host. So you need to uncomment and modify line 11 in the [production configuration file](https://github.com/vault12/zax/blob/main/config/environments/production.rb#L11) `config/environments/production.rb`, uncomment the following line and insert your own URL to allow access to the app from your host:
+
+```ruby
+config.hosts << "zax.example.com" # use your host name
+```
+
+* Disable Zax Dashboard to serve as frontend (optional)
+
+If you want to disable access to the [Zax Dashboard](https://github.com/vault12/zax-dashboard) which provides a convenient UI, set the `public_file_server` variable on line 64 in the [production configuration file](https://github.com/vault12/zax/blob/main/config/environments/production.rb#L64) (`config/environments/production.rb`) to `false`. This action will prevent the Ruby server from serving files from the `public/` directory.
+
+```ruby
+config.public_file_server.enabled = false
+```
+
+* Exit from the **rails** user session by entering `exit`.
+
+## 4. Modify Rails service to serve Zax
+
+* Open `/etc/systemd/system/rails.service` and update the `WorkingDirectory` and `ExecStart` directives as follows:
+
+```bash
+WorkingDirectory=/home/rails/zax/
+ExecStart=/bin/bash -lc 'rails s --binding=localhost --environment production'
+```
+
+Save the changes and exit the editor.
+
+## 5. Add a DNS record for your domain with your registrar
+
+To configure DNS for your domain, log in to your domain registrar's website and access the DNS management section. Add an A record by specifying your domain name and your droplet's IP address. Save the changes and wait for DNS propagation, which may take some time.
+
+## 6. Configure Nginx and secure it with Let's Encrypt
+
+* **Edit the Nginx configuration file**. In `/etc/nginx/sites-available/rails`), replace `server_name _;` with the correct host name (e.g. `server_name zax.example.com;`).
+
+* **Secure Nginx with Let's Encrypt**. Follow the instructions in the Digital Ocean tutorial [How To Secure Nginx with Let's Encrypt on Ubuntu 20.04](https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-20-04) to obtain and install SSL/TLS certificates for your domain. Here are the summarized steps:
+
+1. Allow `Nginx Full` through the firewall and delete the rule for `Nginx HTTP`:
+
+```bash
+ufw allow 'Nginx Full'
+ufw delete allow 'Nginx HTTP'
+```
+
+2. Obtain SSL certificate using Certbot with Nginx plugin:
+
+```bash
+certbot --nginx -d zax.example.com
+```
+
+3. Reload the systemd daemon and restart the Rails service to apply the changes:
+
+```bash
+systemctl daemon-reload
+systemctl restart rails.service
+```
+
+## 7. Verify the installation
+
+Open https://zax.example.com in your browser to ensure Zax Dashboard is served over HTTPS.

README.md

@@ -132,6 +132,10 @@ To make Zax accept connections from all hosts:
 rails s -p 8080 --binding=0.0.0.0
 ```
 
+#### Deployment
+
+For instructions on deploying a custom Zax relay node on [Digital Ocean](https://www.digitalocean.com), refer to [DEPLOYMENT.md](DEPLOYMENT.md).
+
 #### Testing Zax
 
 To test groups of tests you can run any of these commands: