When this works, "Simple build-time configuring Zonemaster-GUI using 'config.ts'" in zonemaster/zonemaster#1442 must be updated correct instructions.

@tbleckert and @rhedman, do you see any issues with the solution in this PR?

2. Run npm run release to build the GUI.

Not npm run build first? Or is that done automatically?

Are the changes in src/layouts/BaseLayout.astro is to resolve the bug with missing favicon only? Or is it related to the core issue of this PR?

@tbleckert and @rhedman, do you see any issues with the solution in this PR?

I don't see any issues, looks good!

Not npm run build first? Or is that done automatically?

npm run release is defined as npm run build && node scripts/create_release.js, so yes, it is fine to only run npm run release.

Are the changes in src/layouts/BaseLayout.astro is to resolve the bug with missing favicon only? Or is it related to the core issue of this PR?

Sort of both. While fixing the issue addressed in this PR, I was trying to use the <base> element and I might have changed the favicon URLs then. Just to make sur that everything is loaded from a location within the subdirectory. While related to the ability for the GUI to be served from a subdirectory, it is also an unintended fix of issue #515.

1. Edit `config.ts` and override the `baseUrl` (e.g. `baseUrl: "/some/subdirectory"`) and the `apiBaseUrl` (e.g. `apiBaseUrl: "/some/subdirectory/api"`).

Is it possible to change so that apiBaseUrl is automatically adjusted to match updated baseUrl so that we can have one instead of two steps here?

Is it possible to change so that apiBaseUrl is automatically adjusted to match updated baseUrl so that we can have one instead of two steps here?

Maybe. But the release time is approaching quickly and I do not want to introduce any more changes than necessary. I am not familiar enough with JavaScript or TypeScript to implement such a change.

But your suggestion on the Apache configuration file looks good. I’ll implement it.

I’m not sure these suggestions are going to work. I tried going the <If> route previously but Apache did not like me setting DocumentRoot in an If block and rejected the configuration file with a somewhat cryptic error message.

There is a big difference between If and IfDefine blocks: If blocks are evaluated at each request, while IfDefine is evaluated when the configuration is being parsed. As far as I know, I can’t use anything else but IfDefine here.

Tried it, and Apache rejects the configuration file:

apachectl[1606]: AH00526: Syntax error on line 11 of /etc/apache2/sites-enabled/zonemaster.conf:
apachectl[1606]: Cannot parse condition clause: Variable 'BASE_URL' does not exist
apachectl[1596]: Action 'start' failed.
apachectl[1596]: The Apache error log may have more information.

I got a new suggestion from ChatGTP:

# Update this if the GUI is served from a subdirectory.
# Must start with a slash, no trailing slash.
Define BASE_URL "/"

# Serve the GUI (works for "/" and subdirs).
Alias "${BASE_URL}" "/var/www/html/zonemaster-web-gui/dist"

# --- API base URL as an *environment* variable ---

# Default when BASE_URL = "/"
SetEnv API_BASE_URL "/api"

# If BASE_URL is not "/", use "<base>/api"
<If "'${BASE_URL}' != '/'">
    SetEnv API_BASE_URL "${BASE_URL}/api"
</If>

I will check.

I will suggest a new conf file, if successful.

I propose the following to replace zonemaster.conf-example in the PR. In my proposal you only have to change one variable to change subdirectory and it is more concise. Also submitted as proposals below.

<VirtualHost *:80>

    # BASE_URL can be set and DEFAULT_LANGUAGE can be updated.

    # Uncomment the following line *only* if the GUI is served from a
    # subdirectory. The setting here must match the setting in config.ts.
    # Must start with a slash, but not end with a slash.
    # Define BASE_URL "/subdirectory" # Undefined by default

    # Default language must be updated if "defaultLanguage" in config.ts is
    # changed. Both must match.
    Define DEFAULT_LANGUAGE "en"


    # Nothing to set or update below. #

    DirectoryIndex index.html
    
    <IfDefine BASE_URL>
        Alias ${BASE_URL} /var/www/html/zonemaster-web-gui/dist
        Define API_BASE_URL "${BASE_URL}/api"
    </IfDefine>

    <IfDefine !BASE_URL>
        DocumentRoot /var/www/html/zonemaster-web-gui/dist
        Define API_BASE_URL "/api"
    </IfDefine>

    <Directory /var/www/html/zonemaster-web-gui/dist>
        Options Indexes FollowSymLinks
        AllowOverride None
        Require all granted

        RewriteEngine On
        <IfDefine BASE_URL>
            RewriteBase ${BASE_URL}/
        </IfDefine>

        # Rewrite /result/{anything} to {default_language}/result/id/index.html
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteRule ^result/[^/]+/?$ ${DEFAULT_LANGUAGE}/result/id/index.html [L]

        # Rewrite /{lang}/result/{anything} to /{lang}/result/id/index.html
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteRule ^([^/]+)/result/[^/]+/?$ $1/result/id/index.html [L]
    </Directory>

    <Location "${API_BASE_URL}">
        ProxyPass http://localhost:5000/
        ProxyPassReverse http://localhost:5000/
        ProxyPreserveHost On
    </Location>
</VirtualHost>

I have tested my proposal both with and without subdirectory and for me it has worked correctly.

Else things works well and I have updated the documentation accordingly (see zonemaster/zonemaster@d9fb884).

I propose the following to replace zonemaster.conf-example in the PR. In my proposal you only have to change one variable to change subdirectory and it is more concise. Also submitted as proposals below.

Okay, thanks for the proposal! I’ve committed it in the latest iteration.