regression in vmagent 1.95.0: -dryRun no longer fails for invalid configuration under scrape_config_files

[lauri-paypay]

Describe the bug

Since #5153, vmagent -dryRun exits with status 0 even if the provided configuration is invalid. We use this in CI to check validity of our configuration before deploying.

To Reproduce

echo "asdf" > foo.yaml
echo "scrape_config_files: [foo.yaml]" > promscrape.yaml
docker run --rm -v $(pwd):/tmp victoriametrics/vmagent:v1.96.0-enterprise -eula -dryRun -promscrape.config=/tmp/promscrape.yaml

2023-12-21T08:28:44.248Z	info	VictoriaMetrics/lib/logger/flag.go:12	build version: vmagent-20231212-225303-tags-v1.96.0-enterprise-0-ga771bc255
2023-12-21T08:28:44.248Z	info	VictoriaMetrics/lib/logger/flag.go:13	command-line flags
2023-12-21T08:28:44.248Z	info	VictoriaMetrics/lib/logger/flag.go:20	  -dryRun="true"
2023-12-21T08:28:44.248Z	info	VictoriaMetrics/lib/logger/flag.go:20	  -eula="true"
2023-12-21T08:28:44.248Z	info	VictoriaMetrics/lib/logger/flag.go:20	  -promscrape.config="/tmp/promscrape.yaml"
2023-12-21T08:28:44.248Z	info	VictoriaMetrics/lib/license/copyrights.go:20	Copyright 2018-2023 VictoriaMetrics, Inc - All Rights Reserved. For any questions please contact info@victoriametrics.com
2023-12-21T08:28:44.253Z	error	VictoriaMetrics/lib/promscrape/config.go:466	skipping "/tmp/foo.yaml" at `scrape_config_files` because of failure to parse it: yaml: unmarshal errors:
  line 1: cannot unmarshal !!str `asdf` into []*promscrape.ScrapeConfig
2023-12-21T08:28:44.253Z	info	VictoriaMetrics/app/vmagent/main.go:121	all the configs are ok; exiting with 0 status code

Version

vmagent-20231212-225303-tags-v1.96.0-enterprise-0-ga771bc255

Logs

No response

Screenshots

No response

Used command-line flags

No response

Additional information

No response

[hagen1778]

Related to #4959, commit d5a599b

• Skip unreachable or invalid files specified at scrape_config_files during vmagent startup, since these files may become valid later.
  Previously vmagent was exitting in this case.

[valyala]

@lauri-paypay , vmagent should return error when it encounters invalid scrape_config_files starting from the commit 3ac44ba . The check for invalid scrape_config_files can be disabled by running vmagent with -promscrape.config.strictParse=false command-line flag.

This commit will be included in the next release. In the mean time you can build vmagent from this commit according to these docs and verify whether it works as intended.

[lauri-paypay]

@valyala thanks. I confirmed that the fixed behavior is what I expected.

[valyala]

@lauri-paypay , thanks for the confirmation!

The bugfix has been included in v1.97.0 release. Closing the issue as fixed.