What causes "stdout or stderr is required" in amir20/dozzle?

Pass stdtypes=stdout, stderr, or stdout%2Cstderr in the query string.

stdout or stderr is required

Error message

stdout or stderr is required

What it means

fetchLogsBetweenDates parses the stdtypes query parameter into a bitmask; when neither stdout nor stderr is requested the mask is 0 and the handler rejects the request with 400 "stdout or stderr is required" before doing any container lookup.

Solutions

Pass stdtypes=stdout, stderr, or stdout%2Cstderr in the query string.
Omit other unrecognized values so the mask does not come out empty.
Default to requesting both streams when the caller does not care.

Example fix

// before
const url = `/api/hosts/${host}/containers/${id}/logs?from=${from}&to=${to}`
// after
const url = `/api/hosts/${host}/containers/${id}/logs?from=${from}&to=${to}&stdtypes=stdout%2Cstderr`

Defensive patterns

Strategy: validation

Validate before calling

function assertStdTypes(std) {
  const valid = ['stdout', 'stderr'];
  const parts = (std || '').split(',').filter(Boolean);
  if (parts.length === 0 || parts.some(p => !valid.includes(p))) throw new Error('stdout or stderr is required');
}
assertStdTypes(stdtypes);

Prevention

Always send stdtypes with values limited to stdout and/or stderr.
Default missing stdtypes to 'stdout,stderr' in client code.
Validate query params when constructing API URLs programmatically.

When it happens

Trigger: GET /api/hosts/{host}/containers/{id}/logs with stdtypes missing, empty, or set to an unrecognized value so parseStdTypes returns 0 (e.g. stdtypes=both or stdtypes=1 when only named values are accepted).

Common situations: Hand-built API calls omitting the parameter; scripts copying stream values from other log tools; frontend regressions dropping the query param.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of amir20/dozzle@d9463cbe21 (2026-09-07). Data as JSON: /api/errors/b518d5f506651cb9. Report an issue: GitHub.

Appendix: source

Thrown at internal/web/logs.go:108

	}
	return ids
}

func (h *handler) fetchLogsBetweenDates(w http.ResponseWriter, r *http.Request) {
	plainText := strings.Contains(r.Header.Get("Accept"), "text/plain")
	if plainText {
		w.Header().Set("Content-Type", "text/plain; charset=UTF-8")
	} else {
		w.Header().Set("Content-Type", "application/x-jsonl; charset=UTF-8")
	}

	from, _ := time.Parse(time.RFC3339Nano, r.URL.Query().Get("from"))
	to, _ := time.Parse(time.RFC3339Nano, r.URL.Query().Get("to"))
	id := chi.URLParam(r, "id")

	stdTypes := parseStdTypes(r)
	if stdTypes == 0 {
		http.Error(w, "stdout or stderr is required", http.StatusBadRequest)
		return
	}

	containerService, err := h.hostService.FindContainer(hostKey(r), id, h.resolveLabels(r))
	if err != nil {
		http.Error(w, err.Error(), http.StatusNotFound)
		return
	}

	delta := max(to.Sub(from), time.Second*3)

	var regex *regexp.Regexp
	if r.URL.Query().Has("filter") {
		regex, err = support_web.ParseRegex(r.URL.Query().Get("filter"))
		if err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			return
		}

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