Use textparse in prometheus module helper library

[ChrsMark]

What does this PR do?

Switches to using textparse as discussed at #24707.

This PR extends #27269 so as to make use the textparse in the prometheus helper library which is used by the prometheus, kubernetes and containerd modules.

This will solve the issue of handling the duplicated metrics reported at #18813 -> Testcase

cc: @jsoriano @premendrasingh @vjsamuel

Closes #18813

Testing TODOs

In all cases the number of metrics and their types should be the same with the old and and new library.

Manually test the kubernetes module to ensure that state-* metricsets are not broken

Verified number of events in both branches.

Manually test the prometheus module against a node-exporter ✅

Tested against prom/node-exporter:v0.18.1 . This branch and main collect the same number of metrics and labels. This ensure us that we collect and store the same number of fields.

Manually test the prometheus module against a node-exporter using types and rates ✅

This branch and main collect the same number of metrics and labels. This ensure us that we collect and store the same number of fields.

For the rest of the sanity checks we can rely on unit tests, since those evaluate the produced values too.

node-exporter appendix

1. Define docker-compose.yml as:

version: '2.1'

services:
  nodeexporter:
    command:
    - --path.procfs=/host/proc
    - --path.rootfs=/rootfs
    - --path.sysfs=/host/sys
    - --collector.filesystem.ignored-mount-points=^/(sys|proc|dev|host|etc)($$|/)
    image: prom/node-exporter:v0.18.1
    expose:
    - 9100
    ports:
    - 9100:9100
    restart: unless-stopped
    volumes:
    - /proc:/host/proc:ro
    - /sys:/host/sys:ro
    - /:/rootfs:ro

2. Deploy node-exporter with docker-compose up
3. The prometheus endpoint should be available at 0.0.0.0:9100
4. Enable the prometheus module of metricbeat and configure the collector metricset to collect from 0.0.0.0:9100
5. Start Metricbeat and see metrics flowing to ES

Histogram checks

In order to test that histograms are calculated properly use the following complete example of Prometheus

version: '2.1'
volumes:
  prometheus_data: {}

services:

  prometheus:
    command:
    - --config.file=/etc/prometheus/prometheus.yml
    - --storage.tsdb.path=/prometheus
    - --web.console.libraries=/etc/prometheus/console_libraries
    - --web.console.templates=/etc/prometheus/consoles
    - --storage.tsdb.retention.time=200h
    - --web.enable-lifecycle
    expose:
    - 9090
    image: prom/prometheus:v2.16.0
    ports:
    - 9090:9090
    restart: unless-stopped
    volumes:
    - ./prometheus:/etc/prometheus
    - prometheus_data:/prometheus
   
  nodeexporter:
    command:
    - --path.procfs=/host/proc
    - --path.rootfs=/rootfs
    - --path.sysfs=/host/sys
    - --collector.filesystem.ignored-mount-points=^/(sys|proc|dev|host|etc)($$|/)
    image: prom/node-exporter:v0.18.1
    expose:
    - 9100
    ports:
    - 9100:9100
    restart: unless-stopped
    volumes:
    - /proc:/host/proc:ro
    - /sys:/host/sys:ro
    - /:/rootfs:ro

and

global:
  evaluation_interval: 5s
  scrape_interval: 5s

scrape_configs:
- job_name: nodeexporter
  scrape_interval: 5s
  static_configs:
  - targets:
    - nodeexporter:9100

Histograms can be found at prometheus-ip:9090/metrics.

[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @ChrsMark? 🙏.
For such, you'll need to label your PR with:

• The upcoming major version of the Elastic Stack
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To fixup this pull request, you need to add the backport labels for the needed
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• backport-v8./d.0 is the label to automatically backport to the 8./d branch. /d is the digit

[elasticmachine]

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• Start Time: 2023-01-24T11:04:16.816+0000

• Duration: 74 min 39 sec

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Failed	0
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Total	5609

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[sonarcloud]

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[ChrsMark]

Opening for an early review since we agreed on moving this one forward. Tests have been added, and unit tests of both prometheus and kubernetes module are not breaking. This is a good indicator by now that we don't break the already existent functionalities. I will also focus on testing these 2 scenarios manually too but any review at this point more than welcome.

[jsoriano]

Most of my comments are on code moved in the textparse.go files, so feel free to ignore them by now as this is not added on this PR.

[gizas]

Why is this deleted?

[ChrsMark]

It's not used at all and linter complains about this :)

[gizas]

Small one, can you add details how you installed and tested with prom/node-exporter:v0.18.1 ? Maybe an extra task to update our infraobs documentation?

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
14 Code Smells

No Coverage information
No Duplication information

[jsoriano]

Most of my concerns have been addressed, LGTM, will leave the final decision to your team 🙂

[tetianakravchenko]

LGTM!

[ChrsMark]

Since manual testing have been completed and unit tests are green I'm gonna merge this.