chore: untrack .claude/settings.local.json (already covered by .gitignore)

- Modify Rfc5424Formatter to read decnet_component from LogRecord
  and use it as RFC 5424 APP-NAME field (falls back to 'decnet')
- Add get_logger(component) factory in decnet/logging/__init__.py
  with _ComponentFilter that injects decnet_component on each record
- Wire all five layers to their component tag:
    cli -> 'cli', engine -> 'engine', api -> 'api' (api.py, ingester,
    routers), mutator -> 'mutator', collector -> 'collector'
- Add structured INFO/DEBUG/WARNING/ERROR log calls throughout each
  layer per the defined vocabulary; DEBUG calls are suppressed unless
  DECNET_DEVELOPER=true
- Add tests/test_logging.py covering factory, filter, formatter
  component-awareness, fallback behaviour, and level gating

.claude/settings.local.json

@@ -1,29 +0,0 @@
-{
-  "permissions": {
-    "allow": [
-      "mcp__plugin_context-mode_context-mode__ctx_batch_execute",
-      "mcp__plugin_context-mode_context-mode__ctx_search",
-      "Bash(grep:*)",
-      "Bash(python -m pytest --tb=short -q)",
-      "Bash(pip install:*)",
-      "Bash(pip show:*)",
-      "Bash(python:*)",
-      "Bash(DECNET_JWT_SECRET=\"test-secret-xyz-1234!\" DECNET_ADMIN_PASSWORD=\"test-pass-xyz-1234!\" python:*)",
-      "Bash(ls /home/anti/Tools/DECNET/*.db* /home/anti/Tools/DECNET/test_*.db*)",
-      "mcp__plugin_context-mode_context-mode__ctx_execute_file",
-      "Bash(nc)",
-      "Bash(nmap:*)",
-      "Bash(ping -c1 -W2 192.168.1.200)",
-      "Bash(xxd)",
-      "Bash(curl -s http://192.168.1.200:2375/version)",
-      "Bash(python3 -m json.tool)",
-      "Bash(curl -s http://192.168.1.200:9200/)",
-      "Bash(docker image:*)",
-      "Read(//home/anti/Tools/cowrie/src/cowrie/data/txtcmds/**)",
-      "Read(//home/anti/Tools/cowrie/src/cowrie/data/txtcmds/bin/**)",
-      "mcp__plugin_context-mode_context-mode__ctx_index",
-      "Bash(ls:*)",
-      "mcp__plugin_context-mode_context-mode__ctx_execute"
-    ]
-  }
-}

decnet/cli.py

@@ -8,6 +8,7 @@ Usage:
   decnet services
 """
 
+import logging
 import signal
 from typing import Optional
 
@@ -15,6 +16,7 @@ import typer
 from rich.console import Console
 from rich.table import Table
 
+from decnet.logging import get_logger
 from decnet.env import (
     DECNET_API_HOST,
     DECNET_API_PORT,
@@ -32,6 +34,8 @@ from decnet.ini_loader import load_ini
 from decnet.network import detect_interface, detect_subnet, allocate_ips, get_host_ip
 from decnet.services.registry import all_services
 
+log = get_logger("cli")
+
 app = typer.Typer(
     name="decnet",
     help="Deploy a deception network of honeypot deckies on your LAN.",
@@ -77,6 +81,7 @@ def api(
     import sys
     import os
 
+    log.info("API command invoked host=%s port=%d", host, port)
     console.print(f"[green]Starting DECNET API on {host}:{port}...[/]")
     _env: dict[str, str] = os.environ.copy()
     _env["DECNET_INGEST_LOG_FILE"] = str(log_file)
@@ -115,6 +120,7 @@ def deploy(
 ) -> None:
     """Deploy deckies to the LAN."""
     import os
+    log.info("deploy command invoked mode=%s deckies=%s dry_run=%s", mode, deckies, dry_run)
     if mode not in ("unihost", "swarm"):
         console.print("[red]--mode must be 'unihost' or 'swarm'[/]")
         raise typer.Exit(1)
@@ -234,8 +240,13 @@ def deploy(
         mutate_interval=mutate_interval,
     )
 
+    log.debug("deploy: config built deckies=%d interface=%s subnet=%s", len(config.deckies), config.interface, config.subnet)
     from decnet.engine import deploy as _deploy
     _deploy(config, dry_run=dry_run, no_cache=no_cache, parallel=parallel)
+    if dry_run:
+        log.info("deploy: dry-run complete, no containers started")
+    else:
+        log.info("deploy: deployment complete deckies=%d", len(config.deckies))
 
     if mutate_interval is not None and not dry_run:
         import subprocess  # nosec B404
@@ -290,6 +301,7 @@ def collect(
     """Stream Docker logs from all running decky service containers to a log file."""
     import asyncio
     from decnet.collector import log_collector_worker
+    log.info("collect command invoked log_file=%s", log_file)
     console.print(f"[bold cyan]Collector starting[/] → {log_file}")
     asyncio.run(log_collector_worker(log_file))
 
@@ -322,6 +334,7 @@ def mutate(
 @app.command()
 def status() -> None:
     """Show running deckies and their status."""
+    log.info("status command invoked")
     from decnet.engine import status as _status
     _status()
 
@@ -336,8 +349,10 @@ def teardown(
         console.print("[red]Specify --all or --id <name>.[/]")
         raise typer.Exit(1)
 
+    log.info("teardown command invoked all=%s id=%s", all_, id_)
     from decnet.engine import teardown as _teardown
     _teardown(decky_id=id_)
+    log.info("teardown complete all=%s id=%s", all_, id_)
 
     if all_:
         _kill_api()

decnet/collector/worker.py

@@ -8,13 +8,14 @@ The ingester tails the .json file; rsyslog can consume the .log file independent
 
 import asyncio
 import json
-import logging
 import re
 from datetime import datetime
 from pathlib import Path
 from typing import Any, Optional
 
-logger = logging.getLogger("decnet.collector")
+from decnet.logging import get_logger
+
+logger = get_logger("collector")
 
 # ─── RFC 5424 parser ──────────────────────────────────────────────────────────
 
@@ -139,10 +140,13 @@ def _stream_container(container_id: str, log_path: Path, json_path: Path) -> Non
                     lf.flush()
                     parsed = parse_rfc5424(line)
                     if parsed:
+                        logger.debug("collector: event written decky=%s type=%s", parsed.get("decky"), parsed.get("event_type"))
                         jf.write(json.dumps(parsed) + "\n")
                         jf.flush()
+                    else:
+                        logger.debug("collector: malformed RFC5424 line snippet=%r", line[:80])
     except Exception as exc:
-        logger.debug("Log stream ended for container %s: %s", container_id, exc)
+        logger.debug("collector: log stream ended container_id=%s reason=%s", container_id, exc)
 
 
 # ─── Async collector ──────────────────────────────────────────────────────────
@@ -170,9 +174,10 @@ async def log_collector_worker(log_file: str) -> None:
                 asyncio.to_thread(_stream_container, container_id, log_path, json_path),
                 loop=loop,
             )
-            logger.info("Collecting logs from container: %s", container_name)
+            logger.info("collector: streaming container=%s", container_name)
 
     try:
+        logger.info("collector started log_path=%s", log_path)
         client = docker.from_env()
 
         for container in client.containers.list():
@@ -193,8 +198,9 @@ async def log_collector_worker(log_file: str) -> None:
         await asyncio.to_thread(_watch_events)
 
     except asyncio.CancelledError:
+        logger.info("collector shutdown requested cancelling %d tasks", len(active))
         for task in active.values():
             task.cancel()
         raise
     except Exception as exc:
-        logger.error("Collector error: %s", exc)
+        logger.error("collector error: %s", exc)

decnet/config.py

@@ -48,8 +48,9 @@ class Rfc5424Formatter(logging.Formatter):
         msg      = record.getMessage()
         if record.exc_info:
             msg += "\n" + self.formatException(record.exc_info)
+        app = getattr(record, "decnet_component", self._app)
         return (
-            f"<{prival}>1 {ts} {self._hostname} {self._app}"
+            f"<{prival}>1 {ts} {self._hostname} {app}"
             f" {os.getpid()} {record.name} - {msg}"
         )
 

decnet/engine/deployer.py

@@ -11,6 +11,7 @@ import docker
 from rich.console import Console
 from rich.table import Table
 
+from decnet.logging import get_logger
 from decnet.config import DecnetConfig, clear_state, load_state, save_state
 from decnet.composer import write_compose
 from decnet.network import (
@@ -26,6 +27,7 @@ from decnet.network import (
     teardown_host_macvlan,
 )
 
+log = get_logger("engine")
 console = Console()
 COMPOSE_FILE = Path("decnet-compose.yml")
 _CANONICAL_LOGGING = Path(__file__).parent.parent.parent / "templates" / "decnet_logging.py"
@@ -106,11 +108,14 @@ def _compose_with_retry(
 
 
 def deploy(config: DecnetConfig, dry_run: bool = False, no_cache: bool = False, parallel: bool = False) -> None:
+    log.info("deployment started n_deckies=%d interface=%s subnet=%s dry_run=%s", len(config.deckies), config.interface, config.subnet, dry_run)
+    log.debug("deploy: deckies=%s", [d.name for d in config.deckies])
     client = docker.from_env()
 
     ip_list = [d.ip for d in config.deckies]
     decky_range = ips_to_range(ip_list)
     host_ip = get_host_ip(config.interface)
+    log.debug("deploy: ip_range=%s host_ip=%s", decky_range, host_ip)
 
     net_driver = "IPvlan L2" if config.ipvlan else "MACVLAN"
     console.print(f"[bold cyan]Creating {net_driver} network[/] ({MACVLAN_NETWORK_NAME}) on {config.interface}")
@@ -140,6 +145,7 @@ def deploy(config: DecnetConfig, dry_run: bool = False, no_cache: bool = False,
     console.print(f"[bold cyan]Compose file written[/] → {compose_path}")
 
     if dry_run:
+        log.info("deployment dry-run complete compose_path=%s", compose_path)
         console.print("[yellow]Dry run — no containers started.[/]")
         return
 
@@ -161,12 +167,15 @@ def deploy(config: DecnetConfig, dry_run: bool = False, no_cache: bool = False,
             _compose_with_retry("build", "--no-cache", compose_file=compose_path)
         _compose_with_retry("up", "--build", "-d", compose_file=compose_path)
 
+    log.info("deployment complete n_deckies=%d", len(config.deckies))
     _print_status(config)
 
 
 def teardown(decky_id: str | None = None) -> None:
+    log.info("teardown requested decky_id=%s", decky_id or "all")
     state = load_state()
     if state is None:
+        log.warning("teardown: no active deployment found")
         console.print("[red]No active deployment found (no decnet-state.json).[/]")
         return
 
@@ -193,6 +202,7 @@ def teardown(decky_id: str | None = None) -> None:
         clear_state()
 
         net_driver = "IPvlan" if config.ipvlan else "MACVLAN"
+        log.info("teardown complete all deckies removed network_driver=%s", net_driver)
         console.print(f"[green]All deckies torn down. {net_driver} network removed.[/]")
 
 

decnet/logging/__init__.py

@@ -0,0 +1,42 @@
+"""
+DECNET application logging helpers.
+
+Usage:
+    from decnet.logging import get_logger
+    log = get_logger("engine")   # APP-NAME in RFC 5424 output becomes "engine"
+
+The returned logger propagates to the root logger (configured in config.py with
+Rfc5424Formatter), so level control via DECNET_DEVELOPER still applies globally.
+"""
+
+from __future__ import annotations
+
+import logging
+
+
+class _ComponentFilter(logging.Filter):
+    """Injects *decnet_component* onto every LogRecord so Rfc5424Formatter can
+    use it as the RFC 5424 APP-NAME field instead of the hardcoded "decnet"."""
+
+    def __init__(self, component: str) -> None:
+        super().__init__()
+        self.component = component
+
+    def filter(self, record: logging.LogRecord) -> bool:
+        record.decnet_component = self.component  # type: ignore[attr-defined]
+        return True
+
+
+def get_logger(component: str) -> logging.Logger:
+    """Return a named logger that self-identifies as *component* in RFC 5424.
+
+    Valid components: cli, engine, api, mutator, collector.
+
+    The logger is named ``decnet.<component>`` and propagates normally, so the
+    root handler (Rfc5424Formatter + level gate from DECNET_DEVELOPER) handles
+    output. Calling this function multiple times for the same component is safe.
+    """
+    logger = logging.getLogger(f"decnet.{component}")
+    if not any(isinstance(f, _ComponentFilter) for f in logger.filters):
+        logger.addFilter(_ComponentFilter(component))
+    return logger

decnet/mutator/engine.py

@@ -14,12 +14,14 @@ from decnet.fleet import all_service_names
 from decnet.composer import write_compose
 from decnet.config import DeckyConfig, DecnetConfig
 from decnet.engine import _compose_with_retry
+from decnet.logging import get_logger
 
 from pathlib import Path
 import anyio
 import asyncio
 from decnet.web.db.repository import BaseRepository
 
+log = get_logger("mutator")
 console = Console()
 
 
@@ -28,8 +30,10 @@ async def mutate_decky(decky_name: str, repo: BaseRepository) -> bool:
     Perform an Intra-Archetype Shuffle for a specific decky.
     Returns True if mutation succeeded, False otherwise.
     """
+    log.debug("mutate_decky: start decky=%s", decky_name)
     state_dict = await repo.get_state("deployment")
     if state_dict is None:
+        log.error("mutate_decky: no active deployment found in database")
         console.print("[red]No active deployment found in database.[/]")
         return False
 
@@ -73,12 +77,14 @@ async def mutate_decky(decky_name: str, repo: BaseRepository) -> bool:
     # Still writes files for Docker to use
     write_compose(config, compose_path)
 
+    log.info("mutation applied decky=%s services=%s", decky_name, ",".join(decky.services))
     console.print(f"[cyan]Mutating '{decky_name}' to services: {', '.join(decky.services)}[/]")
 
     try:
         # Wrap blocking call in thread
         await anyio.to_thread.run_sync(_compose_with_retry, "up", "-d", "--remove-orphans", compose_path)
     except Exception as e:
+        log.error("mutation failed decky=%s error=%s", decky_name, e)
         console.print(f"[red]Failed to mutate '{decky_name}': {e}[/]")
         return False
 
@@ -90,8 +96,10 @@ async def mutate_all(repo: BaseRepository, force: bool = False) -> None:
     Check all deckies and mutate those that are due.
     If force=True, mutates all deckies regardless of schedule.
     """
+    log.debug("mutate_all: start force=%s", force)
     state_dict = await repo.get_state("deployment")
     if state_dict is None:
+        log.error("mutate_all: no active deployment found")
         console.print("[red]No active deployment found.[/]")
         return
 
@@ -116,15 +124,20 @@ async def mutate_all(repo: BaseRepository, force: bool = False) -> None:
                 mutated_count += 1
 
     if mutated_count == 0 and not force:
+        log.debug("mutate_all: no deckies due for mutation")
         console.print("[dim]No deckies are due for mutation.[/]")
+    else:
+        log.info("mutate_all: complete mutated_count=%d", mutated_count)
 
 
 async def run_watch_loop(repo: BaseRepository, poll_interval_secs: int = 10) -> None:
     """Run an infinite loop checking for deckies that need mutation."""
+    log.info("mutator watch loop started poll_interval_secs=%d", poll_interval_secs)
     console.print(f"[green]DECNET Mutator Watcher started (polling every {poll_interval_secs}s).[/]")
     try:
         while True:
             await mutate_all(force=False, repo=repo)
             await asyncio.sleep(poll_interval_secs)
     except KeyboardInterrupt:
+        log.info("mutator watch loop stopped")
         console.print("\n[dim]Mutator watcher stopped.[/]")

decnet/web/api.py

@@ -1,5 +1,4 @@
 import asyncio
-import logging
 import os
 from contextlib import asynccontextmanager
 from typing import Any, AsyncGenerator, Optional
@@ -11,12 +10,13 @@ from pydantic import ValidationError
 from fastapi.middleware.cors import CORSMiddleware
 
 from decnet.env import DECNET_CORS_ORIGINS, DECNET_DEVELOPER, DECNET_INGEST_LOG_FILE
+from decnet.logging import get_logger
 from decnet.web.dependencies import repo
 from decnet.collector import log_collector_worker
 from decnet.web.ingester import log_ingestion_worker
 from decnet.web.router import api_router
 
-log = logging.getLogger(__name__)
+log = get_logger("api")
 ingestion_task: Optional[asyncio.Task[Any]] = None
 collector_task: Optional[asyncio.Task[Any]] = None
 
@@ -25,9 +25,11 @@ collector_task: Optional[asyncio.Task[Any]] = None
 async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
     global ingestion_task, collector_task
 
+    log.info("API startup initialising database")
     for attempt in range(1, 6):
         try:
             await repo.initialize()
+            log.debug("API startup DB initialised attempt=%d", attempt)
             break
         except Exception as exc:
             log.warning("DB init attempt %d/5 failed: %s", attempt, exc)
@@ -40,11 +42,13 @@ async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
         # Start background ingestion task
         if ingestion_task is None or ingestion_task.done():
             ingestion_task = asyncio.create_task(log_ingestion_worker(repo))
+            log.debug("API startup ingest worker started")
 
         # Start Docker log collector (writes to log file; ingester reads from it)
         _log_file = os.environ.get("DECNET_INGEST_LOG_FILE", DECNET_INGEST_LOG_FILE)
         if _log_file and (collector_task is None or collector_task.done()):
             collector_task = asyncio.create_task(log_collector_worker(_log_file))
+            log.debug("API startup collector worker started log_file=%s", _log_file)
         elif not _log_file:
             log.warning("DECNET_INGEST_LOG_FILE not set — Docker log collection disabled.")
     else:
@@ -52,7 +56,7 @@ async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
 
     yield
 
-    # Shutdown background tasks
+    log.info("API shutdown cancelling background tasks")
     for task in (ingestion_task, collector_task):
         if task and not task.done():
             task.cancel()
@@ -62,6 +66,7 @@ async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
                 pass
             except Exception as exc:
                 log.warning("Task shutdown error: %s", exc)
+    log.info("API shutdown complete")
 
 
 app: FastAPI = FastAPI(

decnet/web/ingester.py

@@ -1,13 +1,13 @@
 import asyncio
 import os
-import logging
 import json
 from typing import Any
 from pathlib import Path
 
+from decnet.logging import get_logger
 from decnet.web.db.repository import BaseRepository
 
-logger: logging.Logger = logging.getLogger("decnet.web.ingester")
+logger = get_logger("api")
 
 async def log_ingestion_worker(repo: BaseRepository) -> None:
     """
@@ -22,7 +22,7 @@ async def log_ingestion_worker(repo: BaseRepository) -> None:
     _json_log_path: Path = Path(_base_log_file).with_suffix(".json")
     _position: int = 0
 
-    logger.info(f"Starting JSON log ingestion from {_json_log_path}")
+    logger.info("ingest worker started path=%s", _json_log_path)
 
     while True:
         try:
@@ -53,10 +53,11 @@ async def log_ingestion_worker(repo: BaseRepository) -> None:
 
                     try:
                         _log_data: dict[str, Any] = json.loads(_line.strip())
+                        logger.debug("ingest: record decky=%s event_type=%s", _log_data.get("decky"), _log_data.get("event_type"))
                         await repo.add_log(_log_data)
                         await _extract_bounty(repo, _log_data)
                     except json.JSONDecodeError:
-                        logger.error(f"Failed to decode JSON log line: {_line}")
+                        logger.error("ingest: failed to decode JSON log line: %s", _line.strip())
                         continue
 
                     # Update position after successful line read
@@ -65,10 +66,10 @@ async def log_ingestion_worker(repo: BaseRepository) -> None:
         except Exception as _e:
             _err_str = str(_e).lower()
             if "no such table" in _err_str or "no active connection" in _err_str or "connection closed" in _err_str:
-                logger.error(f"Post-shutdown or fatal DB error in ingester: {_e}")
+                logger.error("ingest: post-shutdown or fatal DB error: %s", _e)
                 break  # Exit worker — DB is gone or uninitialized
 
-            logger.error(f"Error in log ingestion worker: {_e}")
+            logger.error("ingest: error in worker: %s", _e)
             await asyncio.sleep(5)
 
         await asyncio.sleep(1)

decnet/web/router/fleet/api_deploy_deckies.py

@@ -1,9 +1,11 @@
-import logging
 import os
 
 from fastapi import APIRouter, Depends, HTTPException
 
-from decnet.config import DEFAULT_MUTATE_INTERVAL, DecnetConfig, _ROOT, log
+from decnet.logging import get_logger
+from decnet.config import DEFAULT_MUTATE_INTERVAL, DecnetConfig, _ROOT
+
+log = get_logger("api")
 from decnet.engine import deploy as _deploy
 from decnet.ini_loader import load_ini_from_string
 from decnet.network import detect_interface, detect_subnet, get_host_ip
@@ -100,7 +102,7 @@ async def api_deploy_deckies(req: DeployIniRequest, current_user: str = Depends(
         }
         await repo.set_state("deployment", new_state_payload)
     except Exception as e:
-        logging.getLogger("decnet.web.api").exception("Deployment failed: %s", e)
+        log.exception("Deployment failed: %s", e)
         raise HTTPException(status_code=500, detail="Deployment failed. Check server logs for details.")
 
     return {"message": "Deckies deployed successfully"}

decnet/web/router/stream/api_stream_events.py

@@ -1,15 +1,15 @@
 import json
 import asyncio
-import logging
 from typing import AsyncGenerator, Optional
 
 from fastapi import APIRouter, Depends, Query, Request
 from fastapi.responses import StreamingResponse
 
 from decnet.env import DECNET_DEVELOPER
+from decnet.logging import get_logger
 from decnet.web.dependencies import get_stream_user, repo
 
-log = logging.getLogger(__name__)
+log = get_logger("api")
 
 router = APIRouter()
 

tests/test_logging.py

@@ -0,0 +1,155 @@
+"""
+Tests for DECNET application logging system.
+
+Covers:
+- get_logger() factory and _ComponentFilter injection
+- Rfc5424Formatter component-aware APP-NAME field
+- Log level gating via DECNET_DEVELOPER
+- Component tags for all five microservice layers
+"""
+
+from __future__ import annotations
+
+import logging
+import os
+import re
+
+import pytest
+
+from decnet.logging import _ComponentFilter, get_logger
+
+# RFC 5424 parser: <PRI>1 TIMESTAMP HOSTNAME APP-NAME PROCID MSGID SD MSG
+_RFC5424_RE = re.compile(
+    r"^<(\d+)>1 "   # PRI
+    r"\S+ "          # TIMESTAMP
+    r"\S+ "          # HOSTNAME
+    r"(\S+) "        # APP-NAME  ← what we care about
+    r"\S+ "          # PROCID
+    r"(\S+) "        # MSGID
+    r"(.+)$",        # SD + MSG
+)
+
+
+def _format_record(logger: logging.Logger, level: int, msg: str) -> str:
+    """Emit a log record through the root handler and return the formatted string."""
+    from decnet.config import Rfc5424Formatter
+    formatter = Rfc5424Formatter()
+    record = logger.makeRecord(
+        logger.name, level, "<test>", 0, msg, (), None
+    )
+    # Run all filters attached to the logger so decnet_component gets injected
+    for f in logger.filters:
+        f.filter(record)
+    return formatter.format(record)
+
+
+class TestGetLogger:
+    def test_returns_logger(self):
+        log = get_logger("cli")
+        assert isinstance(log, logging.Logger)
+
+    def test_logger_name(self):
+        log = get_logger("engine")
+        assert log.name == "decnet.engine"
+
+    def test_filter_attached(self):
+        log = get_logger("api")
+        assert any(isinstance(f, _ComponentFilter) for f in log.filters)
+
+    def test_idempotent_filter(self):
+        log = get_logger("mutator")
+        get_logger("mutator")  # second call
+        component_filters = [f for f in log.filters if isinstance(f, _ComponentFilter)]
+        assert len(component_filters) == 1
+
+    @pytest.mark.parametrize("component", ["cli", "engine", "api", "mutator", "collector"])
+    def test_all_components_registered(self, component):
+        log = get_logger(component)
+        assert any(isinstance(f, _ComponentFilter) for f in log.filters)
+
+
+class TestComponentFilter:
+    def test_injects_attribute(self):
+        f = _ComponentFilter("engine")
+        record = logging.LogRecord("test", logging.INFO, "", 0, "msg", (), None)
+        assert f.filter(record) is True
+        assert record.decnet_component == "engine"  # type: ignore[attr-defined]
+
+    def test_always_passes(self):
+        f = _ComponentFilter("collector")
+        record = logging.LogRecord("test", logging.DEBUG, "", 0, "msg", (), None)
+        assert f.filter(record) is True
+
+
+class TestRfc5424FormatterComponentAware:
+    @pytest.mark.parametrize("component", ["cli", "engine", "api", "mutator", "collector"])
+    def test_app_name_is_component(self, component):
+        log = get_logger(component)
+        line = _format_record(log, logging.INFO, "test message")
+        m = _RFC5424_RE.match(line)
+        assert m is not None, f"Not RFC 5424: {line!r}"
+        assert m.group(2) == component, f"Expected APP-NAME={component!r}, got {m.group(2)!r}"
+
+    def test_fallback_app_name_without_component(self):
+        """Untagged loggers (no _ComponentFilter) fall back to 'decnet'."""
+        from decnet.config import Rfc5424Formatter
+        formatter = Rfc5424Formatter()
+        record = logging.LogRecord("some.module", logging.INFO, "", 0, "hello", (), None)
+        line = formatter.format(record)
+        m = _RFC5424_RE.match(line)
+        assert m is not None
+        assert m.group(2) == "decnet"
+
+    def test_msgid_is_logger_name(self):
+        log = get_logger("engine")
+        line = _format_record(log, logging.INFO, "deploying")
+        m = _RFC5424_RE.match(line)
+        assert m is not None
+        assert m.group(3) == "decnet.engine"
+
+
+class TestLogLevelGating:
+    def test_configure_logging_normal_mode_sets_info(self):
+        """_configure_logging(dev=False) must set root to INFO."""
+        from decnet.config import _configure_logging, Rfc5424Formatter
+        root = logging.getLogger()
+        original_level = root.level
+        original_handlers = root.handlers[:]
+        # Remove any existing RFC5424 handlers so idempotency check doesn't skip
+        root.handlers = [
+            h for h in root.handlers
+            if not (isinstance(h, logging.StreamHandler) and isinstance(h.formatter, Rfc5424Formatter))
+        ]
+        try:
+            _configure_logging(dev=False)
+            assert root.level == logging.INFO
+        finally:
+            root.setLevel(original_level)
+            root.handlers = original_handlers
+
+    def test_configure_logging_dev_mode_sets_debug(self):
+        """_configure_logging(dev=True) must set root to DEBUG."""
+        from decnet.config import _configure_logging, Rfc5424Formatter
+        root = logging.getLogger()
+        original_level = root.level
+        original_handlers = root.handlers[:]
+        root.handlers = [
+            h for h in root.handlers
+            if not (isinstance(h, logging.StreamHandler) and isinstance(h.formatter, Rfc5424Formatter))
+        ]
+        try:
+            _configure_logging(dev=True)
+            assert root.level == logging.DEBUG
+        finally:
+            root.setLevel(original_level)
+            root.handlers = original_handlers
+
+    def test_debug_enabled_in_developer_mode(self, monkeypatch):
+        """Programmatically setting DEBUG on root allows debug records through."""
+        root = logging.getLogger()
+        original_level = root.level
+        root.setLevel(logging.DEBUG)
+        try:
+            assert root.isEnabledFor(logging.DEBUG)
+        finally:
+            root.setLevel(original_level)