VE 8.3: unable to send notification to discord webhook

[NullBy7e]

Hello,

I am unable to use the new feature to send notifications to a discord webhook.
I get the following:

Could not test target: https://discord.com/api/webhooks/1309266664881389629/2m26U8LC0Hh..<snip>: status code 400 (500)



I believe the JSON is correct as I've put this in a webhook tester and the message gets through.

Any ideas?

 

[dakralex]

Hey NullBy7e!

I could reproduce the problem by setting up a Discord webhook endpoint myself. It seems like that Discord has a problem with escaping characters and is more stricter on the webhook request body, so to fix this problem you can use the escape helper on the two properties in the request body like so:

{"content":null,"embeds":[{"title":"```{{ escape title }}```","description":"```{{ escape message }}```","color":null,"footer":{"text":"Proxmox"}}],"attachments":[]}

 

[NullBy7e]

Hi dakralex,

Thank you, escape did the trick!

Hopefully this will be of help to others when they encounter this issue.

 

[Lukas Wagner]

For further reference, I want to briefly illustrate why escape is needed.

If you use {{ message }} in the body template, it will be expanded to to the full notification message content. For illustrative purposes, let's assume that the notification content is

Backup finished.

Visit the web interface for more details.

Let's assume that you want to include this message in a JSON payload:

{
  "body": "{{ message }}"
}

When the body template is rendered, the result would be the following:

{
  "body": "Backup finished
 
Visit the web interface for more details"
}

As you can see, the result is a malformed JSON payload, because the message contained in {{ message }} contains line breaks and also potentially other characters that need to be escaped.

Now, if we change the body template as follows:

{
  "body": "{{ escape message }}"
}

then the control characters will be escaped properly, resulting in valid JSON:

{
  "body": "Backup finished\nVisit the web interface for more details"
}

I hope this helps!