The Sensu Slack handler is a Sensu Event Handler that sends event data to a configured Slack channel.

Assets are the best way to make use of this handler. If you're not using an asset, please consider doing so! If you're using sensuctl 5.13 or later, you can use the following command to add the asset:

sensuctl asset add sensu/sensu-slack-handler

If you're using an earlier version of sensuctl, you can download the asset definition from this project's Bonsai Asset Index page.

slack-handler.json

{
    "api_version": "core/v2",
    "type": "Handler",
    "metadata": {
        "namespace": "default",
        "name": "slack"
    },
    "spec": {
        "type": "pipe",
        "command": "sensu-slack-handler --channel '#general' --timeout 20 --username 'sensu' ",
        "env_vars": [
            "SLACK_WEBHOOK_URL=https://www.webhook-url-for-slack.com"
        ],

        "timeout": 30,
        "filters": [
            "is_incident"
        ],
        "runtime_assets": ["sensu-slack-handler"]
    }
}

sensuctl create -f slack-handler.json

sensu-slack-handler.yml

---
api_version: core/v2
type: Handler
metadata:
  namespace: default
  name: slack
spec:
  type: pipe
  command: 'sensu-slack-handler --channel ''#general'' --timeout 20 --username ''sensu'' '
  env_vars:
  - SLACK_WEBHOOK_URL=https://www.webhook-url-for-slack.com
  timeout: 30
  filters:
  - is_incident
  runtime_assets:
  - sensu-slack-handler

sensuctl create -f slack-handler.yml

Example Sensu Go check definition:

check-dummy-app-healthz.json

{
    "api_version": "core/v2",
    "type": "CheckConfig",
    "metadata": {
        "namespace": "default",
        "name": "dummy-app-healthz"
    },
    "spec": {
        "command": "check-http -u http://localhost:8080/healthz",
        "subscriptions":[
            "dummy"
        ],
        "publish": true,
        "interval": 10,
        "handlers": [
            "slack"
        ]
    }
}

check-dummy-app-healthz.yml

---
api_version: core/v2
type: CheckConfig
metadata:
  namespace: default
  name: dummy-app-healthz
spec:
  command: check-http -u http://localhost:8080/healthz
  subscriptions:
  - dummy
  publish: true
  interval: 10
  handlers:
  - slack

Security Note: The Slack webhook url is treated as a security sensitive configuration option in this example and is loaded into the handler config as an env_var instead of as a command argument. Command arguments are commonly readable from the process table by other unprivaledged users on a system (ex: ps and top commands), so it's a better practise to read in sensitive information via environment variables or configuration files on disk. The --webhook-url flag is provided as an override for testing purposes.

Help:

The Sensu Go Slack handler for notifying a channel

Usage:
  sensu-slack-handler [flags]

Flags:
  -c, --channel string       The channel to post messages to (default "#general")
  -h, --help                 help for handler-slack
  -i, --icon-url string      A URL to an image to use as the user avatar (default "http://s3-us-west-2.amazonaws.com/sensuapp.org/sensu.png")
  -t, --timeout int          The amount of seconds to wait before terminating the handler (default 10)
  -u, --username string      The username that messages will be sent as (default "sensu")
  -w, --webhook-url string   The webhook url to send messages to, defaults to value of SLACK_WEBHOOK_URL env variable

The preferred way of installing and deploying this plugin is to use it as an [asset]. If you would like to compile and install the plugin from source, or contribute to it, download the latest version of the sensu-slack-handler from releases, or create an executable script from this source.

From the local path of the slack-handler repository:

go build -o /usr/local/bin/sensu-slack-handler main.go