crowdsecurity/crowdsec · error

only one 'follow_stderr' parameters is required, not many

Error message

only one 'follow_stderr' parameters is required, not many

What it means

Validation guard in ConfigureByDSN of the docker source: boolean DSN parameters like 'follow_stderr' must appear at most once; the query string repeated the parameter, which is ambiguous, so configuration fails.

Source

Thrown at pkg/acquisition/modules/docker/config.go:277

			d.containerLogsOptions.Until = v[0]
		case "since":
			if len(v) != 1 {
				return errors.New("only one 'since' parameters is required, not many")
			}
			d.containerLogsOptions.Since = v[0]
		case "follow_stdout":
			if len(v) != 1 {
				return errors.New("only one 'follow_stdout' parameters is required, not many")
			}
			followStdout, err := strconv.ParseBool(v[0])
			if err != nil {
				return fmt.Errorf("parsing 'follow_stdout' parameters: %s", err)
			}
			d.Config.FollowStdout = followStdout
			d.containerLogsOptions.ShowStdout = followStdout
		case "follow_stderr":
			if len(v) != 1 {
				return errors.New("only one 'follow_stderr' parameters is required, not many")
			}
			followStdErr, err := strconv.ParseBool(v[0])
			if err != nil {
				return fmt.Errorf("parsing 'follow_stderr' parameters: %s", err)
			}
			d.Config.FollowStdErr = followStdErr
			d.containerLogsOptions.ShowStderr = followStdErr
		case "docker_host":
			if len(v) != 1 {
				return errors.New("only one 'docker_host' parameters is required, not many")
			}
			opts = append(opts, client.WithHost(v[0]))
		}
	}

	d.Client, err = client.New(opts...)
	if err != nil {
		return err

View on GitHub (pinned to 909b515798)

Solutions

1. Specify follow_stderr=true or false exactly once
2. Combine with a single follow_stdout if you need both streams

When it happens

Trigger: Thrown at pkg/acquisition/modules/docker/config.go:277 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of crowdsecurity/crowdsec@909b515798 (2026-09-06). Data as JSON: /api/errors/7c4ac4170a03aae9. Report an issue: GitHub.