Generate a redirects file compatible with the http.redir plugin from Caddy.

Add the module import to your Hugo config file:

module:
  imports:
    # other imports
    - path: github.com/hacdias/hugo-caddy-redirs

Then enable the output file for home:

# Optional: disable the generation of HTML aliases.
disableAliases: true

# Mandatory
outputs:
  home:
    - html # Default
    - rss # Default
    - redir

This will create a redirects.txt file on the root of your website. Now you can add a rule to your Caddy configuration to use this file as the 301 redirects:

redir 301 {
  import /the/public/path/redirects.txt
}

Thanks to @jlelse for the improvement on adding the version with and without the trailing slash.

MIT