crowdsecurity/crowdsec · critical

failed to load postovflw parser patterns: %w

Error message

failed to load postovflw parser patterns: %w

What it means

LoadParsers wraps any failure from NewUnixParserCtx (which loads the pattern/hydra data files used by the postoverflow parser stage) into "failed to load postovflw parser patterns". Crowdsec cannot run its postoverflow parsing stage without these pattern files (regexes, date formats, etc.), so startup aborts. The wrapped %w contains the underlying cause, typically a missing or unreadable data directory.

Source

Thrown at pkg/parser/unix_parser.go:124

}

func LoadParsers(cConfig *csconfig.Config, hub *cwhub.Hub) (*Parsers, error) {
	var err error

	patternDir := cConfig.ConfigPaths.PatternDir
	log.Infof("Loading grok library %s", patternDir)

	parsers := NewParsers(hub)

	/* load base regexps for two grok parsers */
	parsers.Ctx, err = NewUnixParserCtx(patternDir, cConfig.ConfigPaths.DataDir)
	if err != nil {
		return nil, fmt.Errorf("failed to load parser patterns: %w", err)
	}

	parsers.PovfwCtx, err = NewUnixParserCtx(patternDir, cConfig.ConfigPaths.DataDir)
	if err != nil {
		return nil, fmt.Errorf("failed to load postovflw parser patterns: %w", err)
	}

	/*
		Load enrichers
	*/
	log.Info("Loading enrich plugins")

	parsers.EnricherCtx, err = Loadplugin()
	if err != nil {
		return nil, fmt.Errorf("failed to load enrich plugin: %w", err)
	}

	/*
	 Load the actual parsers
	*/

	log.Infof("Loading parsers from %d files", len(parsers.StageFiles))

View on GitHub (pinned to 909b515798)

Solutions

1. Run `cscli hub update && cscli hub upgrade` (or `cscli parsers install crowdsecurity/geoip-enrich` equivalents) to populate the data/patterns directory
2. Verify ConfigPaths.DataDir in config.yaml points to a directory containing the pattern files (e.g. /var/lib/crowdsec/data/) and that the crowdsec user can read them
3. Check the wrapped error (%w) in the log to see which file open failed and restore that file
4. If in a container/image, ensure the data directory is copied or mounted correctly

Example fix

// before (config.yaml)
config_paths:
  data_dir: /var/lib/crowdsec/dat   # typo
// after
config_paths:
  data_dir: /var/lib/crowdsec/data

import "os"
func dataDirReady(dir string) error {
  pat := filepath.Join(dir, "patterns")
  if st, err := os.Stat(pat); err != nil || !st.IsDir() {
    return fmt.Errorf("pattern dir missing: %s", pat)
  }
  return nil
}

parsers, err := parser.LoadParsers(cfg)
if err != nil {
  if strings.Contains(err.Error(), "postovflw parser patterns") {
    log.Fatalf("pattern data missing; run 'cscli hub update && cscli hub upgrade': %v", err)
  }
  return err
}

When it happens

Trigger: Calling LoadParsers (or cscli/crowdsec startup via initCrowdsec) when NewUnixParserCtx(patternDir, cConfig.ConfigPaths.DataDir) fails — usually because the pattern directory or DataDir does not exist, or its pattern files cannot be read.

Common situations: Fresh installs where `cscli hub update && cscli hub upgrade` was never run so /var/lib/crowdsec/data is empty; a config pointing ConfigPaths.DataDir to a wrong path; running crowdsec in a container without the data volume mounted; partial hub upgrade that removed pattern files.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

• failed to load parser config: %w
• no configuration paths provided
• while parsing '%s': %w
• loading online client credentials: %w
• unable to find grok %q: %v

AI-assisted analysis of crowdsecurity/crowdsec@909b515798 (2026-09-06). Data as JSON: /api/errors/5bbc3722d6b0004a. Report an issue: GitHub.