glm-5.1
161049a17d
Security review #005 identified critical vulnerabilities in the Unix domain socket admin API (C1 symlink race, C2 no auth, C3 info leak, W1-W7, S1-S6). ADR-028 (already accepted) replaces the socket with an authenticated HTTP admin API on the health check port. This commit adds the remaining spec work: - ADR-029: Config file TOCTOU mitigation (mtime check on reload) - ADR-030: Store cli_allow_wildcard_bind in ConfigReloadHandle for consistent reload validation - Implementation tasks for the admin HTTP migration (fix/admin-http-api), TOCTOU fix (fix/config-reload-toctou), and wildcard flag fix (fix/wildcard-flag-reload) - Updated review #005 status to resolved with per-finding disposition - Resolved OQ-16: POST for state-changing admin endpoints, GET for read-only - Updated all architecture docs to reference new ADRs, use admin_key_path instead of admin_socket_path, and reflect POST method for /admin/reload
76 lines
2.7 KiB
Markdown
76 lines
2.7 KiB
Markdown
# ADR-014: Unix Domain Socket Config Reload API
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## Status
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Superseded by [ADR-028](028-admin-http-api.md)
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## Context
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The proxy supports config reload via SIGHUP (ADR-009). SIGHUP is simple and
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well-understood, but has limitations:
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1. No feedback — the sender doesn't know if the reload succeeded or failed
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2. No structured input — you can only signal "reload", not specify which parts
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to reload or pass validation context
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3. Requires process signal permissions — not all deployment tools can send
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signals
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A Unix domain socket API would allow programmatic config reload with
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success/failure status, enabling integration with CI/CD pipelines, admin
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tools, and automated configuration management.
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## Decision
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Add a Unix domain socket API for config reload alongside SIGHUP. The socket
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accepts commands and returns structured responses.
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The socket path is configurable via `admin_socket_path` in StaticConfig
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(default: `/run/reverse-proxy/admin.sock`). Setting it to empty string
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disables the admin socket.
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Initial commands:
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- `reload` — Re-read config file, validate, and swap DynamicConfig. Returns
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`{"status": "ok"}` or `{"status": "error", "message": "..."}`.
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- `status` — Return basic process info (uptime, config load time, site count).
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Returns `{"status": "ok", "uptime_secs": 1234, "sites": 2}`.
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Future commands (not in Phase 1, but the protocol supports extension):
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- `metrics` — Return Prometheus-compatible metrics
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- `shutdown` — Graceful shutdown command
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## Rationale
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- Providing reload feedback is operationally valuable — CI/CD pipelines can
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verify config changes before proceeding
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- The implementation cost is low — a Unix domain socket listener is ~50 lines
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of tokio code, and the command protocol is simple
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- SIGHUP is retained as a fallback for environments where socket access is
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inconvenient
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- This pattern will integrate naturally with alknet's admin interface when the
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projects merge
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- Unix domain sockets are filesystem-permission-based, providing access control
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without additional authentication
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- The socket path is configurable, allowing deployment-specific paths
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## Consequences
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**Positive:**
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- Config reload with success/failure feedback
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- Programmatic integration with CI/CD and admin tools
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- Structured response format enables automation
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- SIGHUP still works as fallback
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- Natural path to future admin commands
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**Negative:**
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- Additional listener and command parsing logic (~100-150 lines)
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- Socket file management (cleanup on startup, stale socket detection)
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- One more config option (`admin_socket_path`)
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## References
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- [operations.md](../operations.md)
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- [config.md](../config.md)
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- ADR-009 (signal handling — SIGHUP retained as fallback)
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- OQ-04 (now resolved) |