# Copyright 2019 The inspec-gcp-cis-benchmark Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
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title 'Ensure That the Log Metric Filter and Alerts Exist for VPC Network Route Changes'

gcp_project_id = input('gcp_project_id')
cis_version = input('cis_version')
cis_url = input('cis_url')
control_id = '2.8'
control_abbrev = 'logging'

control "cis-gcp-#{control_id}-#{control_abbrev}" do
  impact 'low'

  title "[#{control_abbrev.upcase}] Ensure That the Log Metric Filter and Alerts Exist for VPC Network Route Changes"

  desc 'It is recommended that a metric filter and alarm be established for Virtual Private Cloud (VPC) network route changes.'
  desc 'rationale', "Google Cloud Platform (GCP) routes define the paths network traffic takes from a VM instance to another destination. The other destination can be inside the organization VPC network (such as another VM) or outside of it. Every route consists of a destination and a next hop. Traffic whose destination IP is within the destination range is sent to the next hop for delivery.

  Monitoring changes to route tables will help ensure that all VPC traffic flows through an expected path."

  tag cis_scored: true
  tag cis_level: 2
  tag cis_gcp: control_id.to_s
  tag cis_version: cis_version.to_s
  tag project: gcp_project_id.to_s
  tag nist: %w[AU-3 AU-12]

  ref 'CIS Benchmark', url: cis_url.to_s
  ref 'GCP Docs', url: 'https://cloud.google.com/logging/docs/logs-based-metrics/'
  ref 'GCP Docs', url: 'https://cloud.google.com/monitoring/custom-metrics/'
  ref 'GCP Docs', url: 'https://cloud.google.com/monitoring/alerts/'
  ref 'GCP Docs', url: 'https://cloud.google.com/logging/docs/reference/tools/gcloud-logging'
  ref 'GCP Docs', url: 'https://cloud.google.com/storage/docs/access-control/iam'
  ref 'GCP Docs', url: 'https://cloud.google.com/sdk/gcloud/reference/beta/logging/metrics/create'
  ref 'GCP Docs', url: 'https://cloud.google.com/sdk/gcloud/reference/alpha/monitoring/policies/create'

  log_filter = 'resource.type=global AND jsonPayload.event_subtype="compute.routes.delete" OR jsonPayload.event_subtype="compute.routes.insert"'
  describe "[#{gcp_project_id}] VPC Route changes filter" do
    subject { google_project_metrics(project: gcp_project_id).where(metric_filter: log_filter) }
    it { should exist }
  end

  google_project_metrics(project: gcp_project_id).where(metric_filter: log_filter).metric_types.each do |metrictype|
    describe.one do
      filter = "metric.type=\"#{metrictype}\" resource.type=\"global\""
      google_project_alert_policies(project: gcp_project_id).where(policy_enabled_state: true).policy_names.each do |policy|
        condition = google_project_alert_policy_condition(policy: policy, filter: filter)
        describe "[#{gcp_project_id}] VPC Route changes alert policy" do
          subject { condition }
          it { should exist }
        end
      end
    end
  end
end
