how to configure sensu keepalive to throw an alert to slack - docker

Question

I want to send out an slack alert. when a client fails a keep alive check.
What is the process to do it? can I know how to do it? I am using hiroakis/docker-sensu-server docker image.

Answer 1

On the slack side:
on the slack side you have to create a new incoming webhook to your desired channel.
On the sensu side:
you create a new handler that uses the webhook.
then you have to assign this handler to be used for the checks you desire in their check configuration file.
If you need a proxy to connect to the internet keep in mind to put that one in the handler as well or in a more elegant way pass it on via the config file.
eg. you can use this handler:
#!/usr/bin/env ruby
# Copyright 2014 Dan Shultz and contributors.
#
# Released under the same terms as Sensu (the MIT license); see LICENSE
# for details.
#
# In order to use this plugin, you must first configure an incoming webhook
# integration in slack. You can create the required webhook by visiting
# https://{your team}.slack.com/services/new/incoming-webhook
#
# After you configure your webhook, you'll need the webhook URL from the integration.
require 'rubygems' if RUBY_VERSION < '1.9.0'
require 'sensu-handler'
require 'json'
class Slack < Sensu::Handler
option :json_config,
description: 'Configuration name',
short: '-j JSONCONFIG',
long: '--json JSONCONFIG',
default: 'slack'
def slack_webhook_url
get_setting('webhook_url')
end
def slack_channel
get_setting('channel')
end
def slack_proxy_addr
get_setting('proxy_addr')
end
def slack_proxy_port
get_setting('proxy_port')
end
def slack_message_prefix
get_setting('message_prefix')
end
def slack_bot_name
get_setting('bot_name')
end
def slack_surround
get_setting('surround')
end
def markdown_enabled
get_setting('markdown_enabled') || true
end
def incident_key
#event['client']['name'] + '/' + #event['check']['name']
end
def get_setting(name)
settings[config[:json_config]][name]
end
def handle
description = #event['check']['notification'] || build_description
post_data("*Check*\n#{incident_key}\n\n*Description*\n#{description}")
end
def build_description
[
#event['check']['output'].strip,
#event['client']['address'],
#event['client']['subscriptions'].join(',')
].join(' : ')
end
def post_data(notice)
uri = URI(slack_webhook_url)
if (defined?(slack_proxy_addr)).nil?
http = Net::HTTP.new(uri.host, uri.port)
else
http = Net::HTTP::Proxy(slack_proxy_addr, slack_proxy_port).new(uri.host, uri.port)
end
http.use_ssl = true
begin
req = Net::HTTP::Post.new("#{uri.path}?#{uri.query}")
text = slack_surround ? slack_surround + notice + slack_surround : notice
req.body = payload(text).to_json
response = http.request(req)
verify_response(response)
rescue Exception => e
puts "An error has ocurred when posting to slack: #{e.message}"
end
end
def verify_response(response)
case response
when Net::HTTPSuccess
true
else
fail response.error!
end
end
def payload(notice)
{
icon_url: 'http://sensuapp.org/img/sensu_logo_large-c92d73db.png',
attachments: [{
text: [slack_message_prefix, notice].compact.join(' '),
color: color
}]
}.tap do |payload|
payload[:channel] = slack_channel if slack_channel
payload[:username] = slack_bot_name if slack_bot_name
payload[:attachments][0][:mrkdwn_in] = %w(text) if markdown_enabled
end
end
def color
color = {
0 => '#36a64f',
1 => '#FFCC00',
2 => '#FF0000',
3 => '#6600CC'
}
color.fetch(check_status.to_i)
end
def check_status
#event['check']['status']
end
end
and then pass a config file like this on to it
{
"handlers": {
"slack": {
"command": "/etc/sensu/handlers/slack.rb",
"type": "pipe",
"filters": [
],
"severities": [
"ok",
"critical"
]
}
}
}
which then would also include which severities to be handled by that handler