[BUG] Alerting Webhooks incorrectly rejecting URL's

[sangdrax8]

Describe the bug
The Webhook URL in the Alerting destination seems to reject valid URLs.

Other plugins installed
Testing with the OD ELK distribution with no modifications.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Alerting'
2. Click on 'Destinations'
3. Click 'Add destination'
4. Give it a name and select "Slack"
5. Create a webhook with "https://chat.testing/api/v1/external/slack_incoming?api_key=EvV7edIz9P6y7Ud5RrdwSbWxDpfkdysyew"

It seems to accept it "https://chat.test/api/v1/external/slack_incoming?api_key=EvV7edIz9P6y7Ud5RrdwSbWxDpfkdysyew"

The only difference is the length of the fake domain used, which shouldn't change anything. Official domains for testing include .example and .invalid, which fail just like this one.

Expected behavior
Destination should be added

Desktop (please complete the following information):

• OS: Ubuntu 20.04
• Browser Chrome
• Version 91.0.4472.77

Additional context
I only tested enough to find out that the length of the domain would change the outcome. I don't know if there are other underlying issues with the URL, but the domain changing certainly shouldn't be affecting it.

[sangdrax8]

Any update on this? The fact that the alerting page can't be auto-refreshed makes me more dependent on notifications... yet this bug prevents me from doing that either. I am left with just e-mail, which right now is not watched nearly as closely.

[sangdrax8]

For anyone else who runs into this, I believe you can get around this issue by using the API to crate your destination. Although I haven't seen mine work just yet, I can create it. Now I am dealing with TLS issues, but that makes me believe it accepted the URL at least.