(fix) Improve collabora's regex (#1108)

* Improve collabora's regex

* Also allow root domains, and disallow `--`

* Shorten regex steps a bit

charts/stable/collabora-online/SCALE/questions.yaml

@@ -79,7 +79,7 @@ questions:
           schema:
             type: string
             default: 'nextcloud.domain.tld|othernextcloud.domain.tld'
-            valid_chars: '^([a-z]{1,}\.[a-z]{1,}\.[a-z]{1,})((\|[a-z]{1,}\.[a-z]{1,}\.[a-z]{1,}))*$'
+            valid_chars: '^(([a-z\d](-?[a-z\d]){0,62})\.)*(([a-z\d](-?[a-z\d]){0,62})\.)([a-z](-?[a-z\d]){1,62})((\|((([a-z\d](-?[a-z\d]){0,62})\.)*(([a-z\d](-?[a-z\d]){0,62})\.)([a-z](-?[a-z\d]){1,62})))*)$'
             required: true
         - variable: username
           label: "Username for WebUI"
@@ -118,7 +118,8 @@ questions:
           schema:
             type: string
             default: 'collabora.domain.tld'
-            valid_chars: '^([a-z]{1,}\.[a-z]{1,}\.[a-z]{1,})$'
+            valid_chars: '^(([a-z\d](-?[a-z\d]){0,62})\.)*(([a-z\d](-?[a-z\d]){0,62})\.)([a-z](-?[a-z\d]){1,62})$'
+
 # Include{containerConfig}
 
   - variable: service

docs/apps/stable/collabora-online/validation.md

@@ -3,19 +3,39 @@
 __`Domain(s) using collabora`__
 Accepted formats are:
 
-- Single domain (eg. `cloud.mydomain.com`)
-- Multiple domains (eg. `cloud.mydomain.com|nextcloud.mydomain.com`) - Each domain is separated with `|`
+- Single FQDN (eg. `cloud.mydomain.com` or `mydomain.com`)
+- Multiple FQDN (eg. `cloud.mydomain.com|nextcloud.mydomain.com` or `mydomain.com|cname.mydomain.com`) - Each FQDN is separated with `|`
 
-Regex used to match those: `^([a-z]{1,}\.[a-z]{1,}\.[a-z]{1,})((\|[a-z]{1,}\.[a-z]{1,}\.[a-z]{1,}))*$`
-You can try live [here](https://regex101.com/r/AQFh2g/1)
+Each FQDN is split into parts
+* Hostname (`cname`.domain.com) _Optional_
+  * Can have from 1 up to 127 levels deep cnames.
+  * Can contain [0-9], [a-z] and `-`.
+  * Must be at least 1 char and no longer than 63 chars.
+  * Must start with [a-z], [0-9].
+  * Must NOT end with `-`.
+* Domain (cname.`domain`.com)
+  * Can contain [0-9], [a-z] and `-`.
+  * Must be at least 1 chars and no longer than 63 chars.
+  * Must start with [a-z], [0-9].
+  * Must NOT end with `-`.
+* Top-Level-Domains (cname.domain.`com`)
+  * Can contain [0-9], [a-z] and `-`.
+  * Must be at least 2 chars and no longer than 63 chars.
+  * Must start with [a-z].
+  * Must NOT end with `-`.
+
+Regex used to match those: `^(([a-z\d](-?[a-z\d]){0,62})\.)*(([a-z\d](-?[a-z\d]){0,62})\.)([a-z](-?[a-z\d]){1,62})((\|((([a-z\d](-?[a-z\d]){0,62})\.)*(([a-z\d](-?[a-z\d]){0,62})\.)([a-z](-?[a-z\d]){1,62})))*)$`
+You can try live [here](https://regex101.com/r/rIxhye/1)
 
 __`Server Name`__
 Accepted formats are:
 
-- Single domain (eg. `collabora.mydomain.com`)
+- Single FQDN (eg. `collabora.mydomain.com` or `mydomain.com`)
 
-Regex used to match this: `^([a-z]{1,}\.[a-z]{1,}\.[a-z]{1,})$`
-You can try live [here](https://regex101.com/r/xCjpW7/1)
+_Same rules apply for FQDN as in the section above_
+
+Regex used to match this: `^(([a-z\d](-?[a-z\d]){0,62})\.)*(([a-z\d](-?[a-z\d]){0,62})\.)([a-z](-?[a-z\d]){1,62})$`
+You can try live [here](https://regex101.com/r/0HpkSI/1)
 
 __`Password for WebUI`__
 Accepted formats are: