This implements HTTP/HTTPS support for pulse-sensor-proxy to enable
temperature monitoring across multiple separate Proxmox instances.
Architecture changes:
- Dual-mode operation: Unix socket (local) + HTTPS (remote)
- Unix socket remains default for security/performance (no breaking change)
- HTTP mode enables temps from external PVE hosts
Backend implementation:
- Add HTTPS server with TLS + Bearer token authentication to sensor-proxy
- Add TemperatureProxyURL and TemperatureProxyToken fields to PVEInstance
- Add HTTP client (internal/tempproxy/http_client.go) for remote proxy calls
- Update temperature collector to prefer HTTP proxy when configured
- Fallback logic: HTTP proxy → Unix socket → direct SSH (if not containerized)
Configuration:
- pulse-sensor-proxy config: http_enabled, http_listen_addr, http_tls_cert/key, http_auth_token
- PVEInstance config: temperature_proxy_url, temperature_proxy_token
- Environment variables: PULSE_SENSOR_PROXY_HTTP_* for all HTTP settings
Security:
- TLS 1.2+ with modern cipher suites
- Constant-time token comparison (timing attack prevention)
- Rate limiting applied to HTTP requests (shared with socket mode)
- Audit logging for all HTTP requests
Next steps:
- Update installer script to support HTTP mode + auto-registration
- Add Pulse API endpoint for proxy registration
- Generate TLS certificates during installation
- Test multi-instance temperature collection
Related to #571 (multi-instance architecture)
Related to #637
The sensor-proxy was failing to start on systems with read-only filesystems
because audit logging required a writable /var/log/pulse/sensor-proxy directory.
Changes:
- Modified newAuditLogger() to automatically fall back to stderr (systemd journal)
if the audit log file cannot be opened
- Removed error return from newAuditLogger() since it now always succeeds
- Added warning logs when fallback mode is used to alert operators
- Updated tests to handle the new signature
- Added better debugging to audit log tests
This allows the sensor-proxy to run on:
- Immutable/read-only root filesystems
- Hardened systems with restricted /var mounts
- Containerized environments with limited write access
Audit events are still captured via systemd journal when file logging is
unavailable, maintaining the security audit trail.
