T6949: adds blackbox exporter

[nvollmar]

Change Summary

Adds Prometheus Blackbox Exporter

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

• https://vyos.dev/T6949

Related PR(s)

• T6949: Adds build for blackbox exporter deb package vyos-build#871
• T6949: Adds documentation for blackbox exporter vyos-documentation#1582

Component(s) name

monitoring

Proposed changes

Adding Blackbox Exporter allows Prometheus to probe endpoints over HTTP, HTTPS, DNS, TCP, ICMP and gRPC.
This can deliver metrics about upstream connectivity, dns service responsiveness etc.

How to test

Enable blackbox_exporter

set service monitoring prometheus blackbox-exporter listen-address 0.0.0.0

Then check service is running

curl localhost:9115

Smoketest result

vyos:~$ /usr/libexec/vyos/tests/smoke/cli/test_service_monitoring_prometheus.py
test_01_node_exporter (__main__.TestMonitoringPrometheus.test_01_node_exporter) ... ok
test_02_frr_exporter (__main__.TestMonitoringPrometheus.test_02_frr_exporter) ... ok
test_03_blackbox_exporter (__main__.TestMonitoringPrometheus.test_03_blackbox_exporter) ... ok
test_04_blackbox_exporter_with_config (__main__.TestMonitoringPrometheus.test_04_blackbox_exporter_with_config) ... ok

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[nvollmar]

The smoke tests won't work until the vyos-build changes are in the image.

[sever-sever]

Do we need to update debian/control?

[nvollmar]

Do we need to update debian/control?

Aadded

[github-actions]

CI integration ❌ failed!

Details

CI logs

• CLI Smoketests (no interfaces) ❌ failed
• CLI Smoketests (interfaces only) 👍 passed
• Config tests 👍 passed
• RAID1 tests 👍 passed
• TPM tests 👍 passed

[sever-sever]

Integration failed by not this feature