kwesterfeld2 and satterly Fix alert payload formatting issue where template text could introduc…
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caused the json.loads() to fail.  The code now properly logs with a traceback any issues
with template formatting, and in DEBUG will print what its doing and what the template
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README.md
alerta_slack.py
setup.py

README.md

Slack Plugin

Send alerts to Slack.

Slack Message

For help, join Gitter chat

Installation

Clone the GitHub repo and run:

$ python setup.py install

Or, to install remotely from GitHub run:

$ pip install git+https://github.com/alerta/alerta-contrib.git#subdirectory=plugins/slack

Note: If Alerta is installed in a python virtual environment then plugins need to be installed into the same environment for Alerta to dynamically discover them.

Configuration

Add slack to the list of enabled PLUGINS in alertad.conf server configuration file and set plugin-specific variables either in the server configuration file or as environment variables.

PLUGINS = ['slack']

To configure the Slack plugin start by setting up an incoming webhook integration for your Slack channel and adding the following configuration settings to alertad.conf:

SLACK_WEBHOOK_URL = 'https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX'
SLACK_ATTACHMENTS = True  # default=False
SLACK_CHANNEL = '' # if empty then uses channel from incoming webhook configuration
SLACK_CHANNEL_ENV_MAP = { 'Production' : '#alert-prod' } # Default=None (optionnal) Allow to specify a channel on a per-environment basis. SLACK_CHANNEL is used a default value

ICON_EMOJI = '' # default :rocket:
ALERTA_USERNAME = '' # default alerta

The DASHBOARD_URL setting should be configured to link Slack messages to the Alerta console:

DASHBOARD_URL = ''  # default="not set"

The SLACK_SUMMARY_FMT configuration variable is a Jinja2 template string and accepts any Jinja2 syntax. The formatter has access to the following variables in the template environment:

| Variable | Description | | alert | For all alert details | | status | The updated alert status | | config | alerta configuration | | color | The computed severity color | | channel | The computed channel | | emoji | The computed emojii |

If you have Jinja2 available you can try customizing the message like this:

SLACK_SUMMARY_FMT = '*[{{ alert.status|capitalize }}]* [{{ alert.severity|capitalize }}] Event {{ alert.event }} on *{{ alert.environment }} - {{ alert.resource }}*: {{alert.value}}\n{{alert.text}}\nAlert Console: <{{ config.DASHBOARD_URL }}|click here> / Alert: <{{ config.DASHBOARD_URL }}/#/alert/{{ alert.id }}|{{ alert.id[:8] }}>'

Slack Payload

Sometimes the defaults chosen by the plugin won't be flexible enough. In this case, it is possible to use the full capability of the Slack post message API, documented here: https://api.slack.com/methods/chat.postMessage.

To utilize the API, one must craft the HTTP POST payload, which is possible by utilizing the Jinja2 template format mechanism, and supplying a SLACK_PAYLOAD configuration. Each part of the template can be fully customized by template expansion.

You can utilize the full power of the Slack API with this approach, including adding images, interactive buttons and menus.

Example:

SLACK_PAYLOAD = {
  "channel": "{{ channel }}",
  "emoji": ":fire:",
  "text": "*[{{ alert.environment }}]* :: _{{ status }}_ :: _{{ alert.severity|capitalize }}_ :: _{{ alert.value }}_\n```{{ alert.text }}```",
  "attachments": [{
    "color": "{{ color }}",
    "fields": [
      {"title": "Resource", "value": "{{ alert.resource }}", "short": False },
      {"title": "Services", "value": "{{ alert.service|join(', ') }}", "short": False },
      {"title": "Event", "value": "{{ alert.event }}", "short": True },
      {"title": "Origin", "value": "{{ alert.origin }}", "short": True },
    ],
    "actions": [
      { "type": "button", "text": "Alert Console", "url": "{{ config.DASHBOARD_URL }}/#/alert/{{ alert.id }}" },
    ]
 }]
}

Slack Apps API

To use the Slack "Apps" API instead of an Incoming Webhook, create an application and obtain its OAuth token. Use that to set SLACK_TOKEN and specify the URL endpoint to the new API entrypoint this way:

SLACK_WEBHOOK_URL = 'https://slack.com/api/chat.postMessage'
SLACK_TOKEN = 'xoxp-903711738716-407999999999-433333333331-a844444444488888888822222222220c'

Ensure SLACK_CHANNEL is set for the default channel for alerts. You may still use SLACK_CHANNEL_ENV_MAP.

References

License

Copyright (c) 2016 Nick Satterly. Available under the MIT License.