Managing and customizing Nginx

About Nginx

Applications deployed with Cloud 66 use Nginx as their web server, and its configuration is dependant on the resources of your server(s). Nginx is a high performance, open source web server used by some of the biggest web services in the world.

Boolean variables

To ensure correct boolean condition checks within your template, always explicitly compare the variable with true or false (even if you are checking for true).

Good syntax:

• if passenger != true
• if passenger != false
• if passenger == true
• if passenger == false

Bad syntax:

• if passenger
• if !passenger

Default Cloud 66 Nginx error page

When there is a problem with your upstream server (ie. a container), requests will be passed to the default Cloud 66 error page. From there, you can visit the problematic server page in Cloud 66 dashboard to troubleshoot.

You can customise this page by following this guide.

Default Nginx configuration

The following table outlines the default configuration of Nginx.

Nginx CustomConfig variables

The following variables are available for use in your Nginx CustomConfig.

Nginx worker configuration

Nginx now supports autodetection of CPU cores (and other system resources) so there is no need to configure your worker processes differently depending on your cloud.

Customizing Nginx configurations

• Check your template for Liquid syntax errors
• Count the number of cores on the server
• Compile the Nginx configuration based on the information from the server
• Upload the configuration to the server
• Reload Nginx

Reloading Nginx does not interrupt the serving of traffic. This process will be stopped if an error is encountered. For example, if you have 3 web servers in your application, if the first server fails to be updated, the process will be halted for the other 2 servers to avoid complete service disruption.

Working examples

Customizing the Nginx error page

There are two ways for you to create a custom Nginx 50X error page:

1. Using a static page on your own server
   • Make your custom error page (for example 50x/) available in your container (for example in /usr/app), and simply mount this folder to the host (for example with /var/containers:/usr/app). The path used in the next step would then be /var/containers/50x/
   • Customize your Nginx configuration and replace the 50X/ location block with following:

    location = /50x/
    {
        root /var/containers/;
    }

1. Using external static page
   • Upload your file to a server which is accessible from your server
   • Customize your Nginx configuration and replace the 50X/ location block with the following:

    location = /50x/
    {
        proxy_pass {url-of-your-custom-page};
    }

Enabling HTTP2

Nginx supports HTTP2 and this can be enabled on your application by editing your CustomConfig as follows:

Update the listen directive in the server block from this:

server {
        listen 443;
        ssl on;

...to this:

server {
        listen 443 ssl http2;