fix(conpot): add syslog bridge entrypoint for logging pipeline

Conpot is a third-party app with its own Python logger — it never calls
decnet_logging. Added entrypoint.py as a subprocess wrapper that:
- Launches conpot and captures its stdout/stderr
- Classifies each line (startup/request/warning/error/log)
- Extracts source IPs via regex
- Emits RFC 5424 syslog lines to stdout for Docker/collector pickup

Entrypoint is self-contained (no import of shared decnet_logging.py)
because the conpot base image runs Python 3.6, which cannot parse the
dict[str, Any] / str | None type syntax used in the canonical file.

templates/conpot/Dockerfile

@@ -11,8 +11,18 @@ RUN find /opt /usr /etc /home -name "*.xml" -exec sed -i 's/port="5020"/port="50
 RUN (apt-get update && apt-get install -y --no-install-recommends libcap2-bin 2>/dev/null) || (apk add --no-cache libcap 2>/dev/null) || true
 RUN find /home/conpot/.local/bin /usr /opt -type f -name 'python*' -exec setcap 'cap_net_bind_service+eip' {} \; 2>/dev/null || true
 
-# The upstream image already runs as the non-root 'conpot' user.
-# We do NOT switch to a 'decnet' user here — doing so breaks pkg_resources
-# because conpot's eggs live under /home/conpot/.local and are only on the
-# Python path when the interpreter runs as 'conpot'.
+# Bridge conpot's own logger into DECNET's RFC 5424 syslog pipeline.
+# entrypoint.py is self-contained (inlines the formatter) because the
+# conpot base image runs Python 3.6, which cannot import the shared
+# decnet_logging.py (that file uses 3.9+ / 3.10+ type syntax).
+COPY entrypoint.py /home/conpot/entrypoint.py
+RUN chown conpot:conpot /home/conpot/entrypoint.py \
+    && chmod +x /home/conpot/entrypoint.py
+
+# The upstream image already runs as non-root 'conpot'.
+# We do NOT switch to a 'decnet' user — doing so breaks pkg_resources
+# because conpot's eggs live under /home/conpot/.local and are only on
+# the Python path for that user.
 USER conpot
+
+ENTRYPOINT ["/usr/bin/python3", "/home/conpot/entrypoint.py"]

templates/conpot/entrypoint.py

@@ -0,0 +1,144 @@
+#!/usr/bin/env python3
+"""
+Entrypoint wrapper for the Conpot ICS/SCADA honeypot.
+
+Launches conpot as a child process and bridges its log output into the
+DECNET structured syslog pipeline.  Each line from conpot stdout/stderr
+is classified and emitted as an RFC 5424 syslog line so the host-side
+collector can ingest it alongside every other service.
+
+Written to be compatible with Python 3.6 (the conpot base image version).
+"""
+from __future__ import print_function
+
+import os
+import re
+import signal
+import subprocess
+import sys
+from datetime import datetime, timezone
+
+# ── RFC 5424 inline formatter (Python 3.6-compatible) ─────────────────────────
+
+_FACILITY_LOCAL0 = 16
+_SD_ID = "decnet@55555"
+_NILVALUE = "-"
+
+SEVERITY_INFO    = 6
+SEVERITY_WARNING = 4
+SEVERITY_ERROR   = 3
+
+
+def _sd_escape(value):
+    return value.replace("\\", "\\\\").replace('"', '\\"').replace("]", "\\]")
+
+
+def _syslog_line(event_type, severity=SEVERITY_INFO, **fields):
+    pri     = "<{}>".format(_FACILITY_LOCAL0 * 8 + severity)
+    ts      = datetime.now(timezone.utc).isoformat()
+    host    = NODE_NAME[:255]
+    appname = "conpot"
+    msgid   = event_type[:32]
+
+    if fields:
+        params = " ".join('{}="{}"'.format(k, _sd_escape(str(v))) for k, v in fields.items())
+        sd = "[{} {}]".format(_SD_ID, params)
+    else:
+        sd = _NILVALUE
+
+    return "{pri}1 {ts} {host} {appname} {nil} {msgid} {sd}".format(
+        pri=pri, ts=ts, host=host, appname=appname,
+        nil=_NILVALUE, msgid=msgid, sd=sd,
+    )
+
+
+def _log(event_type, severity=SEVERITY_INFO, **fields):
+    print(_syslog_line(event_type, severity, **fields), flush=True)
+
+
+# ── Config ────────────────────────────────────────────────────────────────────
+
+NODE_NAME = os.environ.get("NODE_NAME", "conpot-node")
+TEMPLATE  = os.environ.get("CONPOT_TEMPLATE", "default")
+
+_CONPOT_CMD = [
+    "/home/conpot/.local/bin/conpot",
+    "--template", TEMPLATE,
+    "--logfile", "/var/log/conpot/conpot.log",
+    "-f",
+    "--temp_dir", "/tmp",
+]
+
+# Grab the first routable IPv4 address from a log line
+_IP_RE = re.compile(r"\b((?!127\.)(?!0\.)(?!255\.)\d{1,3}(?:\.\d{1,3}){3})\b")
+
+_REQUEST_RE = re.compile(
+    r"request|recv|received|connect|session|query|command|"
+    r"modbus|snmp|http|s7comm|bacnet|enip",
+    re.IGNORECASE,
+)
+_ERROR_RE   = re.compile(r"error|exception|traceback|critical|fail", re.IGNORECASE)
+_WARN_RE    = re.compile(r"warning|warn", re.IGNORECASE)
+_STARTUP_RE = re.compile(
+    r"starting|started|listening|server|initializ|template|conpot",
+    re.IGNORECASE,
+)
+
+
+# ── Classifier ────────────────────────────────────────────────────────────────
+
+def _classify(raw):
+    """Return (event_type, severity, fields) for one conpot log line."""
+    fields = {}
+
+    m = _IP_RE.search(raw)
+    if m:
+        fields["src"] = m.group(1)
+
+    fields["msg"] = raw[:300]
+
+    if _ERROR_RE.search(raw):
+        return "error", SEVERITY_ERROR, fields
+    if _WARN_RE.search(raw):
+        return "warning", SEVERITY_WARNING, fields
+    if _REQUEST_RE.search(raw):
+        return "request", SEVERITY_INFO, fields
+    if _STARTUP_RE.search(raw):
+        return "startup", SEVERITY_INFO, fields
+    return "log", SEVERITY_INFO, fields
+
+
+# ── Main ──────────────────────────────────────────────────────────────────────
+
+def main():
+    _log("startup", msg="Conpot ICS honeypot starting (template={})".format(TEMPLATE))
+
+    proc = subprocess.Popen(
+        _CONPOT_CMD,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
+        bufsize=1,
+        universal_newlines=True,
+    )
+
+    def _forward(sig, _frame):
+        proc.send_signal(sig)
+
+    signal.signal(signal.SIGTERM, _forward)
+    signal.signal(signal.SIGINT, _forward)
+
+    try:
+        for raw_line in proc.stdout:
+            line = raw_line.rstrip()
+            if not line:
+                continue
+            event_type, severity, fields = _classify(line)
+            _log(event_type, severity, **fields)
+    finally:
+        proc.wait()
+        _log("shutdown", msg="Conpot ICS honeypot stopped")
+        sys.exit(proc.returncode)
+
+
+if __name__ == "__main__":
+    main()