November 2018 Archives

Modern Perl CGI

The contemporarily unique strengths of CGI as a deployment strategy are that CGI scripts ⓐ can just be dumped in the filesystem to deploy them and ⓑ do not have any of the issues of long-running processes: they tie up no resources when not in use and are extremely reliable because of the execution model, in which global state always starts from a blank slate when serving a request and there is no process that outlives the request and could wedge itself. Anyone who consciously chooses CGI over alternative deployment strategies nowadays probably has a fire-and-forget use case where the script will be seeing too little traffic to be worth any effort to tend to it regularly.

In his article about modern CGI, Grinnz suggested using Mojolicious rather than as a framework for writing CGI scripts. Mojolicious is explicitly intended for users who are willing to keep changing their own application code in order to enjoy a framework whose API design can be changed (hopefully for the better) without sacrificing the framework’s code quality. In the Venn diagram of the CGI-for-deployment and Mojolicious-for-framework audiences, there is no overlap. So I consider Mojolicious an oxymoronic alternative to

A much better alternative to is simply raw Plack. It is lower-level than Mojolicious, so the code will be more verbose, but Plack’s stance on compatibility matches a fire-and-forget use case far better. CGI::Alternatives does not do a great job of selling that option, so let’s just see what it would look like in practice for the given example.

About Aristotle

user-pic Waxing philosophical