Customizing Nextcloud Themes and Emails for Multiple Domains

If you're managing a Nextcloud instance that caters to multiple brands or organizations, chances are you'd like to customize the user experience for each domain. Imagine providing distinct themes, logos, and email settings for each of the domains in your Nextcloud setup. This can enhance the branding and user experience for clients accessing Nextcloud from different domains, making it feel more personalized and tailored to each organization.

In this article, we’ll dive into how you can achieve individual themes and email settings per domain on your Nextcloud installation. We'll break down the process step-by-step, covering how to modify the configuration files and handle multiple themes, all while using PHP logic to ensure each domain is served its respective branding.

Why Use Different Themes Per Domain?

Whether you’re hosting Nextcloud for multiple clients, departments, or projects, each domain often corresponds to a different audience. You may want to:

• Customize logos, color schemes, and backgrounds for each client’s domain.
• Adjust email settings, such as the sender's address and domain, to match the branding of each domain.
• Provide different landing pages or introductory messages to users based on which domain they access.

This level of customization helps make your Nextcloud instance more professional and versatile.

Prerequisites

Before we dive into the technical details, ensure that you have:

• Administrative access to your Nextcloud installation.
• Basic familiarity with editing PHP files on your server.
• Access to your Nextcloud’s file system, particularly the config.php file.

It’s important to note that we’ll be modifying core configuration files, so back them up before proceeding. These changes should work across most Nextcloud setups, including those installed via Snap packages.

Step 1: Setting Up Trusted Domains

First, you need to set up multiple domains in your Nextcloud instance. Nextcloud uses a config.php file that resides in /path/to/nextcloud/config/ to manage settings, including trusted domains.

For snap installation, the config.php file is located in /var/snap/nextcloud/current/nextcloud/config/ folder.

To allow multiple domains, you need to list them as trusted domains in config.php. Here's an example of how to do it:

<?php
$CONFIG = array (
  'trusted_domains' =>
  array (
    0 => 'localhost',
    1 => 'example1.com',
    2 => 'example2.com',
  ),
);

This tells Nextcloud that requests from these domains are valid. If you don't add them here, users who try to access your Nextcloud instance through any unlisted domain will be blocked by a security check.

Step 2: Using Dynamic Configurations Based on Domain

Next, we will leverage PHP’s dynamic capabilities to serve different configurations based on the domain being accessed. For this, we’ll use a switch statement in a separate configuration file domains.config.php to conditionally load different themes and email settings for each domain.

Here’s an example setup:

<?php
$current_domain = $_SERVER['HTTP_HOST'] ?? 'cloud.example.com';

if (isset($current_domain)) {
    switch ($current_domain) {
        case 'cloud.example1.com':
            return [
                'theme' => 'theme1',
                'mail_from_address' => 'noreply',
                'mail_domain' => 'example1.com',
                'mail_smtpname' => 'noreply@example1.com',
                'mail_smtppassword' => '********',
            ];
        case 'cloud.example2.com':
            return [
                'theme' => 'theme2',
                'mail_from_address' => 'noreply',
                'mail_domain' => 'example2.com',
                'mail_smtpname' => 'noreply@example2.com',
                'mail_smtppassword' => '********',
            ];
        default:
            return [
                'theme' => 'default_theme',
                'mail_from_address' => 'noreply',
                'mail_domain' => 'default.com',
                'mail_smtpname' => 'noreply@default.com',
                'mail_smtppassword' => '********',
            ];
    }
}

In this example:

• $current_domain checks which domain is being used to access the Nextcloud instance.
• The switch statement returns different configurations for each domain, such as email settings and theme names.

Step 3: Creating Themes for Each Domain

Now that you’ve set up the logic to handle multiple domains, the next step is to create themes for each domain. Each theme directory should reside under /themes/ in your Nextcloud directory. For instance, if you want to set up two themes, create directories like this:

/path/to/nextcloud/themes/theme1/
/path/to/nextcloud/themes/theme2/

Within each theme directory, you can customize the following:

• Logo: Place your custom logo in /theme1/core/img/logo.png and /theme2/core/img/logo.png.
• CSS: You can add custom CSS files under /theme1/core/css/ and /theme2/core/css/ to change the color scheme, fonts, and other styling elements.

In your config.php file (or domains.config.php), you can then define the theme for each domain, as shown in the switch statement earlier. Nextcloud will load the appropriate theme directory based on the domain the user accesses.

Step 4: Customizing Email Settings for Each Domain

Apart from themes, you can also customize email settings based on the domain, allowing emails to appear as though they come from the specific domain being accessed. This can be crucial for maintaining brand consistency across multiple organizations or clients.

In the example configuration, we specified different SMTP settings for each domain, including:

• mail_from_address: The "from" address that users will see.
• mail_domain: The domain part of the "from" email (e.g., example1.com).
• mail_smtpname and mail_smtppassword: Credentials for the SMTP server handling outgoing emails.

This ensures that users on example1.com will receive emails from noreply@example1.com, while users on example2.com will get emails from noreply@example2.com.

Step 5: Testing and Troubleshooting

After setting up domain-specific themes and email configurations, it’s important to thoroughly test the setup:

• Access each domain and verify that the correct theme is loaded.
• Send test emails to ensure that the SMTP configuration for each domain works as expected.

In case of issues, check the Nextcloud logs (/path/to/nextcloud/data/nextcloud.log) to identify and resolve errors related to theming or email settings.

Final Thoughts

Customizing themes and email settings for multiple domains on Nextcloud can significantly improve user experience and branding. By using PHP’s dynamic capabilities and leveraging environment variables for security, you can easily manage different configurations for each domain.

This solution is highly scalable and can be extended further to include custom landing pages, language settings, or user group management specific to each domain. Whether you’re a developer managing a multi-tenant Nextcloud instance or a business providing Nextcloud as a service, this setup offers flexibility and personalization options to cater to diverse client needs.

By following these steps, you'll be well on your way to offering a tailored Nextcloud experience for each domain you manage.

Sources

• https://help.nextcloud.com/t/howto-individual-themes-per-domain/27585