feat: multisite with sufolders (#35)

With this commit multisite now also works with subpaths instead of subdomains.

It also simpified the multisite deployment in generall by adding a new MULTISITE environment variable. Depending on its value WORDPRESS_CONFIG_EXTRA gets set in the entrypoint. And the correct .htaccess gets deployed.

Closes #34

I am still new to coopcloud and welcome feedback on my approach. The second commit is not required for #34 so I can remove it again.

Reviewed-on: https://git.coopcloud.tech/coop-cloud/wordpress/pulls/35
Co-authored-by: p4u1 <p4u1_f4u1@riseup.net>
Co-committed-by: p4u1 <p4u1_f4u1@riseup.net>

htaccess.tmpl

@@ -0,0 +1,57 @@
+{{ if eq (env "MULTISITE") "" -}}
+# BEGIN WordPress
+
+RewriteEngine On
+RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
+RewriteBase /
+RewriteRule ^index\.php$ - [L]
+RewriteCond %{REQUEST_FILENAME} !-f
+RewriteCond %{REQUEST_FILENAME} !-d
+RewriteRule . /index.php [L]
+
+# END WordPress
+{{- end -}}
+
+{{- if eq (env "MULTISITE") "subfolder" -}}
+# BEGIN WordPress Multisite
+# Using subfolder network type: https://wordpress.org/documentation/article/htaccess/#multisite
+
+RewriteEngine On
+RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
+RewriteBase /
+RewriteRule ^index\.php$ - [L]
+
+# add a trailing slash to /wp-admin
+RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]
+
+RewriteCond %{REQUEST_FILENAME} -f [OR]
+RewriteCond %{REQUEST_FILENAME} -d
+RewriteRule ^ - [L]
+RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
+RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
+RewriteRule . index.php [L]
+
+# END WordPress Multisite
+{{- end -}}
+
+{{- if eq (env "MULTISITE") "subdomain" -}}
+# BEGIN WordPress Multisite
+# Using subdomain network type: https://wordpress.org/documentation/article/htaccess/#multisite
+
+RewriteEngine On
+RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
+RewriteBase /
+RewriteRule ^index\.php$ - [L]
+
+# add a trailing slash to /wp-admin
+RewriteRule ^wp-admin$ wp-admin/ [R=301,L]
+
+RewriteCond %{REQUEST_FILENAME} -f [OR]
+RewriteCond %{REQUEST_FILENAME} -d
+RewriteRule ^ - [L]
+RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
+RewriteRule ^(.*\.php)$ $1 [L]
+RewriteRule . index.php [L]
+
+# END WordPress Multisite
+{{- end }}