docker/cli · error · invalidParameter

network %q is specified multiple times

Error message

network %q is specified multiple times

What it means

Error "network %q is specified multiple times" thrown in docker/cli.

Source

Thrown at cli/command/container/opts.go:791

		} else {
			hasNonUserDefined = true
		}
		if i == 0 {
			// The first network corresponds with what was previously the "only"
			// network, and what would be used when using the non-advanced syntax
			// `--network-alias`, `--link`, `--ip`, `--ip6`, and `--link-local-ip`
			// are set on this network, to preserve backward compatibility with
			// the non-advanced notation
			if err := applyContainerOptions(&n, copts); err != nil {
				return nil, err
			}
		}
		ep, err := parseNetworkAttachmentOpt(n)
		if err != nil {
			return nil, err
		}
		if _, ok := endpoints[n.Target]; ok {
			return nil, invalidParameter(fmt.Errorf("network %q is specified multiple times", n.Target))
		}

		// For backward compatibility: if no custom options are provided for the network,
		// and only a single network is specified, omit the endpoint-configuration
		// on the client (the daemon will still create it when creating the container)
		if i == 0 && len(copts.netMode.Value()) == 1 {
			if ep == nil || reflect.ValueOf(*ep).IsZero() {
				continue
			}
		}
		endpoints[n.Target] = ep
	}
	if hasUserDefined && hasNonUserDefined {
		return nil, invalidParameter(errors.New("conflicting options: cannot attach both user-defined and non-user-defined network-modes"))
	}
	return endpoints, nil
}

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cli/command/container/opts.go:791 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/b87230a2ca7882b1.json. Report an issue: GitHub.