On a multi-homed host the discovery layer used to walk net.Interfaces()
and pick the first non-loopback IPv4 NIC, while UPnP/SSDP bound a
wildcard UDP socket and let the kernel route the multicast send. That
meant --bind on soundtouch-web only moved the HTTP listener; the
discovery still went out whatever interface the kernel preferred (often
the wrong one on hosts where the speakers sit behind a secondary NIC).
Introduce a separate DiscoveryInterface knob:
* pkg/config: DiscoveryInterface field + DISCOVERY_INTERFACE env var.
* pkg/discovery/mdns: NewMDNSDiscoveryServiceWithInterface; the
interface resolver now honours an explicit name and validates it
has a usable IPv4 address before handing it to hashicorp/mdns.
* pkg/discovery/upnp: when an interface is configured, bind the UDP
socket's source IP to the NIC's IPv4 and call
ipv4.PacketConn.SetMulticastInterface so M-SEARCH leaves the right
NIC. Without an interface, behaviour is unchanged.
* cmd/soundtouch-web: new --interface flag (DISCOVERY_INTERFACE env)
plumbed into the config before the discovery service is built.
go.mod/go.sum reflect promoting golang.org/x/net from indirect to a
direct dependency (now imported for ipv4.PacketConn).
Refs #264.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Reduces `pkg/discovery` test suite runtime by ~75% (from ~17s to ~4s) by eliminating unnecessary network timeouts and reducing wait intervals.
- Refactor `discovery.Service` to use an injectable `http.Client`, allowing UPnP enrichment tests to use `httptest.Server` instead of waiting for 5s network timeouts.
- Make `DNSDiscovery` forward timeout configurable and reduce it from 2s to 100ms in unit tests.
- Decrease discovery and context timeouts in mDNS and Unified discovery tests to the minimum required for stable verification (typically 100-200ms).
Major improvements to device discovery system:
🔧 **SSDP Discovery Fixed**:
- Fixed networking issue where SSDP used connected UDP socket instead of UDP listener
- SSDP now properly receives unicast responses from multicast requests
- UPnP discovery now works reliably and finds all MediaRenderer devices
✨ **Enhanced DiscoveredDevice Model**:
- Added consistent URL fields (APIBaseURL, InfoURL) for all discovery methods
- Added protocol-specific fields (UPnPLocation, UPnPUSN, MDNSHostname, etc.)
- Added DiscoveryMethod tracking to show how devices were found
- Added device merging support for same device found via multiple protocols
🚀 **Unified Discovery Improvements**:
- Fixed device merging logic to properly combine protocol-specific data
- Discovery methods now correctly show combinations like 'Configuration+SSDP/UPnP+mDNS/Bonjour'
- Removed duplicate configuration device loading in individual services
- All three discovery methods (SSDP, mDNS, Configuration) work together seamlessly
🛠 **Updated Tools & Examples**:
- Updated soundtouch-cli to display new consistent field structure
- Enhanced all example programs with better device information display
- Added new unified discovery example demonstrating all three methods
- Fixed context timeout issues in example programs
📋 **Comprehensive Testing**:
- All tests updated and passing
- Real-world validation with actual Bose SoundTouch devices
- Confirmed discovery methods properly merge device data
Every discovered device now has consistent http://host:port/info URLs regardless
of discovery method, while preserving valuable protocol-specific metadata.
Features Added:
• mDNS/Bonjour discovery using hashicorp/mdns library
• Unified discovery service combining UPnP + mDNS + configuration
• Parallel discovery execution for optimal performance
• Comprehensive logging for both UPnP and mDNS discovery
• Network diagnostic tools for troubleshooting
New Discovery Methods:
• Configuration-based (fastest, most reliable)
• UPnP/SSDP discovery (widely supported, enhanced logging)
• mDNS/Bonjour discovery (Apple ecosystem friendly)
New Programs & Tools:
• cmd/example-mdns - Standalone mDNS discovery testing
• cmd/example-upnp - Isolated UPnP/SSDP discovery testing
• cmd/mdns-scanner - Network diagnostic tool for mDNS services
Enhanced Build System:
• make dev-mdns / dev-mdns-verbose (mDNS testing)
• make dev-upnp / dev-upnp-verbose (UPnP testing)
• make dev-scan-all (scan all network services)
• make dev-scan-soundtouch (scan for SoundTouch services)
Documentation:
• docs/DISCOVERY.md - Comprehensive discovery guide
• Updated README.md with new features and commands
• Full API documentation and troubleshooting guide
Technical Improvements:
• Detailed request/response logging for UPnP M-SEARCH
• Step-by-step mDNS service discovery tracking
• IP address resolution with IPv4/IPv6 handling
• Service name parsing and device info extraction
• Robust error handling and network diagnostics
Backward Compatibility:
• No breaking changes to existing APIs
• All existing tests pass
• CLI interface unchanged but enhanced
• Legacy UPnP-only service still available
Tobias GesellchenandClaude Opus 4.7