Merge pull request #1059 from cantino/gap_detector_agent

Add GapDetectorAgent, an Agent that alerts when no data has been received
This commit is contained in:
Andrew Cantino 2015-10-17 11:16:32 -07:00
commit 9aacb8e5f5
3 changed files with 180 additions and 1 deletions

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@ -0,0 +1,67 @@
module Agents
class GapDetectorAgent < Agent
default_schedule "every_10m"
description <<-MD
The Gap Detector Agent will watch for holes or gaps in a stream of incoming Events and generate "no data alerts".
The `value_path` value is a [JSONPath](http://goessner.net/articles/JsonPath/) to a value of interest. If either
this value is empty, or no Events are received, during `window_duration_in_days`, an Event will be created with
a payload of `message`.
MD
event_description <<-MD
Events look like:
{
"message": "No data has been received!",
"gap_started_at": "1234567890"
}
MD
def validate_options
unless options['message'].present?
errors.add(:base, "message is required")
end
unless options['window_duration_in_days'].present? && options['window_duration_in_days'].to_f > 0
errors.add(:base, "window_duration_in_days must be provided as an integer or floating point number")
end
end
def default_options
{
'window_duration_in_days' => "2",
'message' => "No data has been received!"
}
end
def working?
true
end
def receive(incoming_events)
incoming_events.sort_by(&:created_at).each do |event|
memory['newest_event_created_at'] ||= 0
if !interpolated['value_path'].present? || Utils.value_at(event.payload, interpolated['value_path']).present?
if event.created_at.to_i > memory['newest_event_created_at']
memory['newest_event_created_at'] = event.created_at.to_i
memory.delete('alerted_at')
end
end
end
end
def check
window = interpolated['window_duration_in_days'].to_f.days.ago
if memory['newest_event_created_at'].present? && Time.at(memory['newest_event_created_at']) < window
unless memory['alerted_at']
memory['alerted_at'] = Time.now.to_i
create_event payload: { message: interpolated['message'],
gap_started_at: memory['newest_event_created_at'] }
end
end
end
end
end

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@ -7,7 +7,7 @@ module Agents
description <<-MD
The Peak Detector Agent will watch for peaks in an event stream. When a peak is detected, the resulting Event will have a payload message of `message`. You can include extractions in the message, for example: `I saw a bar of: {{foo.bar}}`, have a look at the [Wiki](https://github.com/cantino/huginn/wiki/Formatting-Events-using-Liquid) for details.
The `value_path` value is a [JSONPaths](http://goessner.net/articles/JsonPath/) to the value of interest. `group_by_path` is a hash path that will be used to group values, if present.
The `value_path` value is a [JSONPath](http://goessner.net/articles/JsonPath/) to the value of interest. `group_by_path` is a JSONPath that will be used to group values, if present.
Set `expected_receive_period_in_days` to the maximum amount of time that you'd expect to pass between Events being received by this Agent.

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require 'spec_helper'
describe Agents::GapDetectorAgent do
let(:valid_params) {
{
'name' => "my gap detector agent",
'options' => {
'window_duration_in_days' => "2",
'message' => "A gap was found!"
}
}
}
let(:agent) {
_agent = Agents::GapDetectorAgent.new(valid_params)
_agent.user = users(:bob)
_agent.save!
_agent
}
describe 'validation' do
before do
expect(agent).to be_valid
end
it 'should validate presence of message' do
agent.options['message'] = nil
expect(agent).not_to be_valid
end
it 'should validate presence of window_duration_in_days' do
agent.options['window_duration_in_days'] = ""
expect(agent).not_to be_valid
agent.options['window_duration_in_days'] = "wrong"
expect(agent).not_to be_valid
agent.options['window_duration_in_days'] = "1"
expect(agent).to be_valid
agent.options['window_duration_in_days'] = "0.5"
expect(agent).to be_valid
end
end
describe '#receive' do
it 'records the event if it has a created_at newer than the last seen' do
agent.receive([events(:bob_website_agent_event)])
expect(agent.memory['newest_event_created_at']).to eq events(:bob_website_agent_event).created_at.to_i
events(:bob_website_agent_event).created_at = 2.days.ago
expect {
agent.receive([events(:bob_website_agent_event)])
}.to_not change { agent.memory['newest_event_created_at'] }
events(:bob_website_agent_event).created_at = 2.days.from_now
expect {
agent.receive([events(:bob_website_agent_event)])
}.to change { agent.memory['newest_event_created_at'] }.to(events(:bob_website_agent_event).created_at.to_i)
end
it 'ignores the event if value_path is present and the value at the path is blank' do
agent.options['value_path'] = 'title'
agent.receive([events(:bob_website_agent_event)])
expect(agent.memory['newest_event_created_at']).to eq events(:bob_website_agent_event).created_at.to_i
events(:bob_website_agent_event).created_at = 2.days.from_now
events(:bob_website_agent_event).payload['title'] = ''
expect {
agent.receive([events(:bob_website_agent_event)])
}.to_not change { agent.memory['newest_event_created_at'] }
events(:bob_website_agent_event).payload['title'] = 'present!'
expect {
agent.receive([events(:bob_website_agent_event)])
}.to change { agent.memory['newest_event_created_at'] }.to(events(:bob_website_agent_event).created_at.to_i)
end
it 'clears any previous alert' do
agent.memory['alerted_at'] = 2.days.ago.to_i
agent.receive([events(:bob_website_agent_event)])
expect(agent.memory).to_not have_key('alerted_at')
end
end
describe '#check' do
it 'alerts once if no data has been received during window_duration_in_days' do
agent.memory['newest_event_created_at'] = 1.days.ago.to_i
expect {
agent.check
}.to_not change { agent.events.count }
agent.memory['newest_event_created_at'] = 3.days.ago.to_i
expect {
agent.check
}.to change { agent.events.count }.by(1)
expect(agent.events.last.payload).to eq ({ 'message' => 'A gap was found!',
'gap_started_at' => agent.memory['newest_event_created_at'] })
expect {
agent.check
}.not_to change { agent.events.count }
end
end
end