docker/cli · error

bad format of filter (expected name=value)

Error message

bad format of filter (expected name=value)

What it means

Error "bad format of filter (expected name=value)" thrown in docker/cli.

Source

Thrown at opts/opts.go:309

func (o *FilterOpt) String() string {
	if o == nil || len(o.filter) == 0 {
		return ""
	}
	repr, err := json.Marshal(o.filter)
	if err != nil {
		return "invalid filters"
	}
	return string(repr)
}

// Set sets the value of the opt by parsing the command line value
func (o *FilterOpt) Set(value string) error {
	if value == "" {
		return nil
	}
	if !strings.Contains(value, "=") {
		return errors.New("bad format of filter (expected name=value)")
	}
	name, val, _ := strings.Cut(value, "=")

	// TODO(thaJeztah): these options should not be case-insensitive.
	name = strings.ToLower(strings.TrimSpace(name))
	val = strings.TrimSpace(val)
	o.filter.Add(name, val)
	return nil
}

// Type returns the option type
func (*FilterOpt) Type() string {
	return "filter"
}

// Value returns the value of this option
func (o *FilterOpt) Value() client.Filters {
	return o.filter

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at opts/opts.go:309 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/35a88f7ff06e03a5.json. Report an issue: GitHub.