Custom message color not supported for mattermost

[Thorsieger]

Describe the bug

When using a custom color for mattermost alert message, elastalert crash at startup.

To Reproduce

Add a rule with an mattermost alert and a custom notification color.

mattermost_msg_color: '#FF0000'

logs

Traceback (most recent call last):
  File "/usr/local/lib/python3.13/site-packages/elastalert/loaders.py", line 319, in load_options
    self.rule_schema.validate(rule)
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "/usr/local/lib/python3.13/site-packages/jsonschema/validators.py", line 451, in validate
    raise error
jsonschema.exceptions.ValidationError: '#FF0000' is not one of ['good', 'warning', 'danger']

Failed validating 'enum' in schema['properties']['mattermost_msg_color']:
    {'enum': ['good', 'warning', 'danger']}

On instance['mattermost_msg_color']:
    '#FF0000'

Expected behavior

Documentation state that you can use custom color hex code.

Installation method

• Helm

Additional context
same behavior for slack notifications.

Custom colors are not in the allowed values :

elastalert2/elastalert/schema.yaml

Line 681 in 391cea3

mattermost_msg_color: {enum: [good, warning, danger]}

[nsano-rururu]

@Thorsieger
We are looking forward to a pull request to add the mattermost_custom_msg_color setting and set it to take precedence over mattermost_custom_msg_color if mattermost_custom_msg_color is set.
I think you can do it with the following.
I don't use mattermost so I can't confirm it.

https://github.com/jertel/elastalert2/blob/master/elastalert/schema.yaml#L681

current

mattermost_msg_color: {enum: [good, warning, danger]}

after

mattermost_msg_color:  {type: string}

[nsano-rururu]

Someone made a similar pull request on Slack in the past. The request stopped responding midway and was closed.
#1375

[nsano-rururu]

@Thorsieger

I don't use mattermost, so if you can help me check the operation, I will submit a pull request.

Before submitting the pull request, I will upload a docker image with the modifications to my personal dockerhub, so I would like you to use that to check the operation.

I will update the documentation and fix the test code.

What do you think?

[Thorsieger]

Hello, thank you for the quick response.

I will be happy to try your docker image with the fix !

[nsano-rururu]

@Thorsieger
Please check the operation with the following docker image.
rururukenken/elastalert2:latest

[nsano-rururu]

Since there was no reply, the rururukenken/elastalert2:latest docker image is currently being deleted.