How To Install varnish-selector on Debian 12
Introduction
In this tutorial we learn how to install varnish-selector on Debian 12.
What is varnish-selector
varnish-selector is:
Varnish Module (VMOD) for matching strings against sets of fixed strings. A VMOD object may also function as an associative array, mapping the matched string to one or more of a backend, another string, an integer, or a regular expression. The string may also map to a subroutine that can be invoked.
The VMOD is intended to support a variety of use cases that are typical for VCL deployments, such as:
- Determining the backend based on the Host header or the prefix of the URL.
- Rewriting the URL or a header.
- Generating redirect responses, based on a header or the URL.
- Permitting or rejecting request methods.
- Matching the Basic Authentication credentials in an Authorization request header.
- Matching media types in the Content-Type header of a backend response to determine if the content is compressible.
- Accessing data by string match, as in an associative array, or by numeric index, as in a standard array.
- Dispatching subroutine calls based on string matches.
- Executing conditional logic that depends on features of the request or response that can be determined by matching headers or URLs.
Operations such as these are commonly implemented in native VCL with an if-elsif-elsif sequence of string comparisons or regex matches. As the number of matches increases, such a sequence becomes cumbersome and scales poorly – the time needed to execute the sequence increases with the number of matches to be performed. With the VMOD, the strings to be matched are declared in a tabular form in vcl_init, and the operation is executed in a few lines.
There are three methods to install varnish-selector on Debian 12. We can use apt-get, apt and aptitude. In the following sections we will describe each method. You can choose one of them.
Install varnish-selector Using apt-get
Update apt database with apt-get using the following command.
sudo apt-get update
After updating apt database, We can install varnish-selector using apt-get by running the following command:
sudo apt-get -y install varnish-selector
Install varnish-selector Using apt
Update apt database with apt using the following command.
sudo apt update
After updating apt database, We can install varnish-selector using apt by running the following command:
sudo apt -y install varnish-selector
Install varnish-selector Using aptitude
If you want to follow this method, you might need to install aptitude first since aptitude is usually not installed by default on Debian. Update apt database with aptitude using the following command.
sudo aptitude update
After updating apt database, We can install varnish-selector using aptitude by running the following command:
sudo aptitude -y install varnish-selector
How To Uninstall varnish-selector on Debian 12
To uninstall only the varnish-selector package we can use the following command:
sudo apt-get remove varnish-selector
Uninstall varnish-selector And Its Dependencies
To uninstall varnish-selector and its dependencies that are no longer needed by Debian 12, we can use the command below:
sudo apt-get -y autoremove varnish-selector
Remove varnish-selector Configurations and Data
To remove varnish-selector configuration and data from Debian 12 we can use the following command:
sudo apt-get -y purge varnish-selector
Remove varnish-selector configuration, data, and all of its dependencies
We can use the following command to remove varnish-selector configurations, data and all of its dependencies, we can use the following command:
sudo apt-get -y autoremove --purge varnish-selector
Dependencies
varnish-selector have the following dependencies:
References
Summary
In this tutorial we learn how to install varnish-selector package on Debian 12 using different package management tools: apt, apt-get and aptitude.
