Introducing Request Flow: use Redirection.io, Varnish, reverse proxy with no effort

Clever Cloud exists to ease developers’ life. For many years, you can use Varnish in front of your application just by adding a varnish.vcl file in your repository. For some months, you can also use Redirection.io as a reverse proxy to handle redirects, rewrites, and more. In our latest release, we’ve gone a step further with Request Flow, available in new runtimes first :

• frankenphp
• linux
• python with uv
• static
• v

Easier Redirection.io and Varnish activation

First, we’ve removed some barriers to use Redirection.io and Varnish:

• To setup Varnish add a clevercloud/varnish.vcl file or define it with CC_VARNISH_FILE environment variable
• To setup Redirection.io, CC_REDIRECTIONIO_PROJECT_KEY is now the only required environment variable

Request Flow: automatic port configuration, easy ordering

In recent runtimes where Clever Cloud manage the port configuration (frankenphp, static), nothing else is needed. By default, Clever Cloud will configure the reverse proxy to listen on port 8080 and redirect to port 9000. So in runtimes where the user controls the port configuration, the application must listen on port 9000 once Redirection.io or Varnish is activated.

If both are activated:

• Varnish is exposed first: listens on port 8080, forward to Redirection.io on port 8081
• Redirection.io listens on port 8081, forward to the application on port 9000

If you prefer to invert the order and expose Redirection.io first, set CC_REQUEST_FLOW environment variable to redirectionio,varnish.

Use any reverse proxy with Request Flow

Last but not least, you can use any other middleware in the Request Flow. Just add custom value in the CC_REQUEST_FLOW chain and ports will be automatically configured accordingly. For example, if you set CC_REQUEST_FLOW=redirectionio,custom,varnish:

• Redirection.io listens on port 8080, forward to custom middleware on port 8081
• Custom middleware must listen on port 8081, forward to Varnish on port 8082
• Varnish listens on port 8082, forward to the application on port 9000

You can define the custom middleware command to start with CC_REQUEST_FLOW_CUSTOM environment variable, for example:

CC_REQUEST_FLOW_CUSTOM="./custom_reverse_proxy --listen @@LISTEN_PORT@@ --forward @@FORWARD_PORT@@"

As Request Flow is a new feature on Clever Cloud, feel free to give us feedback.