feat: prometheus-exporter_dnsmasq (#561)

* feat: prometheus-exporter_dnsmasq

* fix: prometheus-exporter_dnsmasq/README.md

---------

Co-authored-by: Jean-Baptiste Simillon <jb.simillon@fr.clara.net>

docs/severity.md

@@ -79,6 +79,7 @@
 - [organization_usage](#organization_usage)
 - [otel-collector_kubernetes-common](#otel-collector_kubernetes-common)
 - [prometheus-exporter_active-directory](#prometheus-exporter_active-directory)
+- [prometheus-exporter_dnsmasq](#prometheus-exporter_dnsmasq)
 - [prometheus-exporter_docker-state](#prometheus-exporter_docker-state)
 - [prometheus-exporter_kong](#prometheus-exporter_kong)
 - [prometheus-exporter_oracledb](#prometheus-exporter_oracledb)
@@ -874,6 +875,15 @@
 |Active-directory active directory services|X|-|-|-|-|
 
 
+## prometheus-exporter_dnsmasq
+
+|Detector|Critical|Major|Minor|Warning|Info|
+|---|---|---|---|---|---|
+|Dnsmasq heartbeat|X|-|-|-|-|
+|Dnsmasq hits|X|-|-|-|-|
+|Dnsmasq hit rate|-|X|X|-|-|
+
+
 ## prometheus-exporter_docker-state
 
 |Detector|Critical|Major|Minor|Warning|Info|

modules/prometheus-exporter_dnsmasq/README.md

@@ -0,0 +1,117 @@
+# DNSMASQ SignalFx detectors
+
+<!-- START doctoc generated TOC please keep comment here to allow auto update -->
+<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
+:link: **Contents**
+
+- [How to use this module?](#how-to-use-this-module)
+- [What are the available detectors in this module?](#what-are-the-available-detectors-in-this-module)
+- [How to collect required metrics?](#how-to-collect-required-metrics)
+ - [Metrics](#metrics)
+- [Related documentation](#related-documentation)
+
+<!-- END doctoc generated TOC please keep comment here to allow auto update -->
+
+## How to use this module?
+
+This directory defines a [Terraform](https://www.terraform.io/)
+[module](https://www.terraform.io/language/modules/syntax) you can use in your
+existing [stack](https://github.com/claranet/terraform-signalfx-detectors/wiki/Getting-started#stack) by adding a
+`module` configuration and setting its `source` parameter to URL of this folder:
+
+```hcl
+module "signalfx-detectors-prometheus-exporter-dnsmasq" {
+ source = "github.com/claranet/terraform-signalfx-detectors.git//modules/prometheus-exporter_dnsmasq?ref={revision}"
+
+ environment = var.environment
+ notifications = local.notifications
+}
+```
+
+Note the following parameters:
+
+* `source`: Use this parameter to specify the URL of the module. The double slash (`//`) is intentional and required.
+ Terraform uses it to specify subfolders within a Git repo (see [module
+ sources](https://www.terraform.io/language/modules/sources)). The `ref` parameter specifies a specific Git tag in
+ this repository. It is recommended to use the latest "pinned" version in place of `{revision}`. Avoid using a branch
+ like `master` except for testing purpose. Note that every modules in this repository are available on the Terraform
+ [registry](https://registry.terraform.io/modules/claranet/detectors/signalfx) and we recommend using it as source
+ instead of `git` which is more flexible but less future-proof.
+
+* `environment`: Use this parameter to specify the
+ [environment](https://github.com/claranet/terraform-signalfx-detectors/wiki/Getting-started#environment) used by this
+ instance of the module.
+ Its value will be added to the `prefixes` list at the start of the [detector
+ name](https://github.com/claranet/terraform-signalfx-detectors/wiki/Templating#example).
+ In general, it will also be used in the `filtering` internal sub-module to [apply
+ filters](https://github.com/claranet/terraform-signalfx-detectors/wiki/Guidance#filtering) based on our default
+ [tagging convention](https://github.com/claranet/terraform-signalfx-detectors/wiki/Tagging-convention) by default.
+
+* `notifications`: Use this parameter to define where alerts should be sent depending on their severity. It consists
+ of a Terraform [object](https://www.terraform.io/language/expressions/type-constraints#object) where each key represents an available
+ [detector rule severity](https://docs.splunk.com/observability/alerts-detectors-notifications/create-detectors-for-alerts.html#severity)
+ and its value is a list of recipients. Every recipients must respect the [detector notification
+ format](https://registry.terraform.io/providers/splunk-terraform/signalfx/latest/docs/resources/detector#notification-format).
+ Check the [notification binding](https://github.com/claranet/terraform-signalfx-detectors/wiki/Notifications-binding)
+ documentation to understand the recommended role of each severity.
+
+These 3 parameters along with all variables defined in [common-variables.tf](common-variables.tf) are common to all
+[modules](../) in this repository. Other variables, specific to this module, are available in
+[variables-gen.tf](variables-gen.tf).
+In general, the default configuration "works" but all of these Terraform
+[variables](https://www.terraform.io/language/values/variables) make it possible to
+customize the detectors behavior to better fit your needs.
+
+Most of them represent usual tips and rules detailed in the
+[guidance](https://github.com/claranet/terraform-signalfx-detectors/wiki/Guidance) documentation and listed in the
+common [variables](https://github.com/claranet/terraform-signalfx-detectors/wiki/Variables) dedicated documentation.
+
+Feel free to explore the [wiki](https://github.com/claranet/terraform-signalfx-detectors/wiki) for more information about
+general usage of this repository.
+
+## What are the available detectors in this module?
+
+This module creates the following SignalFx detectors which could contain one or multiple alerting rules:
+
+|Detector|Critical|Major|Minor|Warning|Info|
+|---|---|---|---|---|---|
+|Dnsmasq heartbeat|X|-|-|-|-|
+|Dnsmasq hits|X|-|-|-|-|
+|Dnsmasq hit rate|-|X|X|-|-|
+
+## How to collect required metrics?
+
+This module deploys detectors using metrics reported by the
+scraping of a server following the [OpenMetrics convention](https://openmetrics.io/) based on and compatible with [the Prometheus
+exposition format](https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#openmetrics-text-format).
+
+They are generally called `Prometheus Exporters` which can be fetched by both the [SignalFx Smart Agent](https://github.com/signalfx/signalfx-agent)
+thanks to its [prometheus exporter monitor](https://github.com/signalfx/signalfx-agent/blob/main/docs/monitors/prometheus-exporter.md) and the
+[OpenTelemetry Collector](https://github.com/signalfx/splunk-otel-collector) using its [prometheus
+receiver](https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/receiver/prometheusreceiver) or its derivatives.
+
+These exporters could be embedded directly in the tool you want to monitor (e.g. nginx ingress) or must be installed next to it as
+a separate program configured to connect, create metrics and expose them as server.
+
+
+Check the [Related documentation](#related-documentation) section for more detailed and specific information about this module dependencies.
+
+
+
+### Metrics
+
+
+Here is the list of required metrics for detectors in this module.
+
+* `dnsmasq_cachesize`
+* `dnsmasq_hits`
+* `dnsmasq_misses`
+
+
+
+
+## Related documentation
+
+* [Terraform SignalFx provider](https://registry.terraform.io/providers/splunk-terraform/signalfx/latest/docs)
+* [Terraform SignalFx detector](https://registry.terraform.io/providers/splunk-terraform/signalfx/latest/docs/resources/detector)
+* [Splunk Observability integrations](https://docs.splunk.com/Observability/gdi/get-data-in/integrations.html)

modules/prometheus-exporter_dnsmasq/common-filters.tf

@@ -0,0 +1 @@
+../../common/module/filters-prometheus-exporter.tf

modules/prometheus-exporter_dnsmasq/common-locals.tf

@@ -0,0 +1 @@
+../../common/module/locals.tf

modules/prometheus-exporter_dnsmasq/common-modules.tf

@@ -0,0 +1 @@
+../../common/module/modules.tf

modules/prometheus-exporter_dnsmasq/common-variables.tf

@@ -0,0 +1 @@
+../../common/module/variables.tf

modules/prometheus-exporter_dnsmasq/common-versions.tf

@@ -0,0 +1 @@
+../../common/module/versions.tf

modules/prometheus-exporter_dnsmasq/conf/00-heartbeat.yaml

@@ -0,0 +1,13 @@
+module: dnsmasq
+name: heartbeat
+
+transformation: false
+aggregation: true
+
+exclude_not_running_vm: true
+
+signals:
+ signal:
+ metric: "dnsmasq_cachesize"
+rules:
+ critical:

modules/prometheus-exporter_dnsmasq/conf/01-cachesize_limit.yaml

@@ -0,0 +1,16 @@
+module: dnsmasq
+name: hits
+id: dnsmasq_hits
+
+transformation: true
+aggregation: true
+
+signals:
+ signal:
+ metric: dnsmasq_hits
+
+rules:
+ critical:
+ threshold: 1
+ comparator: "<="
+ lasting_duration: '5m'

modules/prometheus-exporter_dnsmasq/conf/02-hit-rate.yaml

@@ -0,0 +1,24 @@
+module: dnsmasq
+name: Hit Rate
+id: dnsmasq_hit_rate
+
+transformation: ".min(over='5m')"
+aggregation: true
+
+signals:
+ A:
+ metric: dnsmasq_hits
+ B:
+ metric: dnsmasq_misses
+ signal:
+ formula: (A/(A+B)).fill(0).scale(100)
+rules:
+ minor:
+ threshold: 90
+ comparator: "<"
+ lasting_duration: "5m"
+ dependency: major
+ major:
+ threshold: 80
+ comparator: "<="
+ lasting_duration: "5m"

modules/prometheus-exporter_dnsmasq/conf/readme.yaml

@@ -0,0 +1,3 @@
+documentations:
+
+source_doc:

modules/prometheus-exporter_dnsmasq/detectors-gen.tf

@@ -0,0 +1,97 @@
+resource "signalfx_detector" "heartbeat" {
+ name = format("%s %s", local.detector_name_prefix, "Dnsmasq heartbeat")
+
+ authorized_writer_teams = var.authorized_writer_teams
+ teams = try(coalescelist(var.teams, var.authorized_writer_teams), null)
+ tags = compact(concat(local.common_tags, local.tags, var.extra_tags))
+
+ program_text = <<-EOF
+ from signalfx.detectors.not_reporting import not_reporting
+ signal = data('dnsmasq_cachesize', filter=%{if var.heartbeat_exclude_not_running_vm}${local.not_running_vm_filters} and %{endif}${module.filtering.signalflow})${var.heartbeat_aggregation_function}.publish('signal')
+ not_reporting.detector(stream=signal, resource_identifier=None, duration='${var.heartbeat_timeframe}', auto_resolve_after='${local.heartbeat_auto_resolve_after}').publish('CRIT')
+EOF
+
+ rule {
+ description = "has not reported in ${var.heartbeat_timeframe}"
+ severity = "Critical"
+ detect_label = "CRIT"
+ disabled = coalesce(var.heartbeat_disabled, var.detectors_disabled)
+ notifications = try(coalescelist(lookup(var.heartbeat_notifications, "critical", []), var.notifications.critical), null)
+ runbook_url = try(coalesce(var.heartbeat_runbook_url, var.runbook_url), "")
+ tip = var.heartbeat_tip
+ parameterized_subject = var.message_subject == "" ? local.rule_subject_novalue : var.message_subject
+ parameterized_body = var.message_body == "" ? local.rule_body : var.message_body
+ }
+
+ max_delay = var.heartbeat_max_delay
+}
+
+resource "signalfx_detector" "dnsmasq_hits" {
+ name = format("%s %s", local.detector_name_prefix, "Dnsmasq hits")
+
+ authorized_writer_teams = var.authorized_writer_teams
+ teams = try(coalescelist(var.teams, var.authorized_writer_teams), null)
+ tags = compact(concat(local.common_tags, local.tags, var.extra_tags))
+
+ program_text = <<-EOF
+ signal = data('dnsmasq_hits', filter=${module.filtering.signalflow})${var.dnsmasq_hits_aggregation_function}${var.dnsmasq_hits_transformation_function}.publish('signal')
+ detect(when(signal <= ${var.dnsmasq_hits_threshold_critical}%{if var.dnsmasq_hits_lasting_duration_critical != null}, lasting='${var.dnsmasq_hits_lasting_duration_critical}', at_least=${var.dnsmasq_hits_at_least_percentage_critical}%{endif})).publish('CRIT')
+EOF
+
+ rule {
+ description = "is too low <= ${var.dnsmasq_hits_threshold_critical}"
+ severity = "Critical"
+ detect_label = "CRIT"
+ disabled = coalesce(var.dnsmasq_hits_disabled, var.detectors_disabled)
+ notifications = try(coalescelist(lookup(var.dnsmasq_hits_notifications, "critical", []), var.notifications.critical), null)
+ runbook_url = try(coalesce(var.dnsmasq_hits_runbook_url, var.runbook_url), "")
+ tip = var.dnsmasq_hits_tip
+ parameterized_subject = var.message_subject == "" ? local.rule_subject : var.message_subject
+ parameterized_body = var.message_body == "" ? local.rule_body : var.message_body
+ }
+
+ max_delay = var.dnsmasq_hits_max_delay
+}
+
+resource "signalfx_detector" "dnsmasq_hit_rate" {
+ name = format("%s %s", local.detector_name_prefix, "Dnsmasq hit rate")
+
+ authorized_writer_teams = var.authorized_writer_teams
+ teams = try(coalescelist(var.teams, var.authorized_writer_teams), null)
+ tags = compact(concat(local.common_tags, local.tags, var.extra_tags))
+
+ program_text = <<-EOF
+ A = data('dnsmasq_hits', filter=${module.filtering.signalflow})${var.dnsmasq_hit_rate_aggregation_function}${var.dnsmasq_hit_rate_transformation_function}
+ B = data('dnsmasq_misses', filter=${module.filtering.signalflow})${var.dnsmasq_hit_rate_aggregation_function}${var.dnsmasq_hit_rate_transformation_function}
+ signal = (A/(A+B)).fill(0).scale(100).publish('signal')
+ detect(when(signal < ${var.dnsmasq_hit_rate_threshold_minor}%{if var.dnsmasq_hit_rate_lasting_duration_minor != null}, lasting='${var.dnsmasq_hit_rate_lasting_duration_minor}', at_least=${var.dnsmasq_hit_rate_at_least_percentage_minor}%{endif}) and (not when(signal <= ${var.dnsmasq_hit_rate_threshold_major}%{if var.dnsmasq_hit_rate_lasting_duration_major != null}, lasting='${var.dnsmasq_hit_rate_lasting_duration_major}', at_least=${var.dnsmasq_hit_rate_at_least_percentage_major}%{endif}))).publish('MINOR')
+ detect(when(signal <= ${var.dnsmasq_hit_rate_threshold_major}%{if var.dnsmasq_hit_rate_lasting_duration_major != null}, lasting='${var.dnsmasq_hit_rate_lasting_duration_major}', at_least=${var.dnsmasq_hit_rate_at_least_percentage_major}%{endif})).publish('MAJOR')
+EOF
+
+ rule {
+ description = "is too low < ${var.dnsmasq_hit_rate_threshold_minor}"
+ severity = "Minor"
+ detect_label = "MINOR"
+ disabled = coalesce(var.dnsmasq_hit_rate_disabled_minor, var.dnsmasq_hit_rate_disabled, var.detectors_disabled)
+ notifications = try(coalescelist(lookup(var.dnsmasq_hit_rate_notifications, "minor", []), var.notifications.minor), null)
+ runbook_url = try(coalesce(var.dnsmasq_hit_rate_runbook_url, var.runbook_url), "")
+ tip = var.dnsmasq_hit_rate_tip
+ parameterized_subject = var.message_subject == "" ? local.rule_subject : var.message_subject
+ parameterized_body = var.message_body == "" ? local.rule_body : var.message_body
+ }
+
+ rule {
+ description = "is too low <= ${var.dnsmasq_hit_rate_threshold_major}"
+ severity = "Major"
+ detect_label = "MAJOR"
+ disabled = coalesce(var.dnsmasq_hit_rate_disabled_major, var.dnsmasq_hit_rate_disabled, var.detectors_disabled)
+ notifications = try(coalescelist(lookup(var.dnsmasq_hit_rate_notifications, "major", []), var.notifications.major), null)
+ runbook_url = try(coalesce(var.dnsmasq_hit_rate_runbook_url, var.runbook_url), "")
+ tip = var.dnsmasq_hit_rate_tip
+ parameterized_subject = var.message_subject == "" ? local.rule_subject : var.message_subject
+ parameterized_body = var.message_body == "" ? local.rule_body : var.message_body
+ }
+
+ max_delay = var.dnsmasq_hit_rate_max_delay
+}
+

modules/prometheus-exporter_dnsmasq/outputs.tf

@@ -0,0 +1,15 @@
+output "dnsmasq_hit_rate" {
+ description = "Detector resource for dnsmasq_hit_rate"
+ value = signalfx_detector.dnsmasq_hit_rate
+}
+
+output "dnsmasq_hits" {
+ description = "Detector resource for dnsmasq_hits"
+ value = signalfx_detector.dnsmasq_hits
+}
+
+output "heartbeat" {
+ description = "Detector resource for heartbeat"
+ value = signalfx_detector.heartbeat
+}
+

modules/prometheus-exporter_dnsmasq/tags.tf

@@ -0,0 +1,4 @@
+locals {
+ tags = ["prometheus-exporter", "dnsmasq"]
+}
+