cannot have 'servers' global options with duplicate listener

Error message

cannot have 'servers' global options with duplicate listener addresses: %s

What it means

Error "cannot have 'servers' global options with duplicate listener addresses: %s" thrown in caddyserver/caddy.

Source

Thrown at caddyconfig/httpcaddyfile/httptype.go:450

			}
			options[opt] = append(existingOpts, defaultBindOpts...)
			continue
		}

		options[opt] = val
	}

	// If we got "servers" options, we'll sort them by their listener address
	if serverOpts, ok := options["servers"].([]serverOptions); ok {
		sort.Slice(serverOpts, func(i, j int) bool {
			return len(serverOpts[i].ListenerAddress) > len(serverOpts[j].ListenerAddress)
		})

		// Reject the config if there are duplicate listener address
		seen := make(map[string]bool)
		for _, entry := range serverOpts {
			if _, alreadySeen := seen[entry.ListenerAddress]; alreadySeen {
				return nil, fmt.Errorf("cannot have 'servers' global options with duplicate listener addresses: %s", entry.ListenerAddress)
			}
			seen[entry.ListenerAddress] = true
		}
	}

	return serverBlocks[1:], nil
}

// extractNamedRoutes pulls out any named route server blocks
// so they don't get parsed as sites, and stores them in options
// for later.
func (ServerType) extractNamedRoutes(
	serverBlocks []serverBlock,
	options map[string]any,
	warnings *[]caddyconfig.Warning,
	replacer ShorthandReplacer,
) ([]serverBlock, error) {
	namedRoutes := map[string]*caddyhttp.Route{}

View on GitHub (pinned to 50e54ee279)

Solutions

Remove the duplicate 'servers' global options block for that listener address, or merge the options into a single block.

When it happens

Trigger: Thrown at caddyconfig/httpcaddyfile/httptype.go:450 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of caddyserver/caddy@50e54ee279 (2026-08-15). Data as JSON: /api/errors/fdbea8c758ec6564. Report an issue: GitHub.