Allow environment variables via shortcode in hugo

[jorgemoralespou]

Is your feature request related to a problem? Please describe.

In classic renderer one could use ENV_ prefix to use environment variables. This is not possible in hugo renderer.

Per the docs:

If using the hugo renderer there is no builtin equivalent for this feature, although you could provide your own shortcode for Hugo to use which implements it if desired.

An easy shortcode env.html can be created with this content:

{{- $name := "" }}
{{- if .IsNamedParams }}
  {{- $name = .Get "name" }}
{{- else }}
  {{- $name = .Get 0 }}
{{- end }}
{{ getenv $name }}

But then in hugo, security feature prevents from reading variables not defined in config.toml. Erroring with something like this:

Error: error building site: render: failed to render pages: render of "/opt/workshop/content/05-configure-vscode.md" failed: "/opt/eduk8s/etc/themes/educates/layouts/_default/single.html:18:13": execute of template failed: template: _default/single.html:18:13: executing "main" at <.Content>: error calling Content: "/opt/workshop/content/05-configure-vscode.md:26:13": failed to render shortcode "env": failed to process shortcode: "/opt/workshop/layouts/shortcodes/env.html:7:3": execute of template failed: template: shortcodes/env.html:7:3: executing "shortcodes/env.html" at <getenv $name>: error calling getenv: access denied: "LITELLM_API_KEY" is not whitelisted in policy "security.funcs.getenv"; the current security configuration is:

[security]
  enableInlineShortcodes = false

  [security.exec]
    allow = ['^(dart-)?sass(-embedded)?$', '^go$', '^git$', '^npx$', '^postcss$', '^tailwindcss$']
    osEnv = ['(?i)^((HTTPS?|NO)_PROXY|PATH(EXT)?|APPDATA|TE?MP|TERM|GO\w+|(XDG_CONFIG_)?HOME|USERPROFILE|SSH_AUTH_SOCK|DISPLAY|LANG|SYSTEMDRIVE)$']

  [security.funcs]
    getenv = ['^HUGO_', '^CI$']

  [security.http]
    methods = ['(?i)GET|POST']
    urls = ['.*']

Describe the solution you'd like

I would like to be able to use environment variables that are defined in the platform to render content, like it was possible in classic renderer.

Describe alternatives you've considered

No response

Additional information

No response

[GrahamDumpleton]

Create a workshop/config.yaml file and put in it:

params:
- name: OPENAI_MODEL
  value: undefined

You can then use:

{{< param OPENAI_MODEL >}}

The definition in the workshop/config.yaml will cause the corresponding environment variable to be injected as a parameter and be available to use with param short code.

The ENV_ hack in Classic renderer was reluctantly done because of people not wanting to use the more explicit way of declaring what environment variables should be converted to params (which provided default values, renaming etc). In Hugo it was dropped to push people back to be more explicit about it.

See:

• https://docs.educates.dev/en/stable/workshop-content/workshop-instructions.html#adding-custom-data-variables