decnet/composer.py

@@ -69,8 +69,11 @@ def generate_compose(config: DecnetConfig) -> dict:
 
             # Inject the per-decky base image into build services so containers
             # vary by distro and don't all fingerprint as debian:bookworm-slim.
+            # Services that need a fixed upstream image (e.g. conpot) can pre-set
+            # build.args.BASE_IMAGE in their compose_fragment() to opt out.
             if "build" in fragment:
-                fragment["build"].setdefault("args", {})["BASE_IMAGE"] = decky.build_base
+                args = fragment["build"].setdefault("args", {})
+                args.setdefault("BASE_IMAGE", decky.build_base)
 
             fragment.setdefault("environment", {})
             fragment["environment"]["HOSTNAME"] = decky.hostname

decnet/services/conpot.py

@@ -1,4 +1,3 @@
-import os
 from pathlib import Path
 from decnet.services.base import BaseService
 
@@ -24,7 +23,8 @@ class ConpotService(BaseService):
 
         return {
             "build": {
-                "context": str(self.dockerfile_context())
+                "context": str(self.dockerfile_context()),
+                "args": {"BASE_IMAGE": "honeynet/conpot:latest"},
             },
             "container_name": f"{decky_name}-conpot",
             "restart": "unless-stopped",

templates/conpot/Dockerfile

@@ -3,21 +3,16 @@ FROM ${BASE_IMAGE}
 
 USER root
 
-# Replace 5020 with 502 in all templates
+# Replace 5020 with 502 in all templates so Modbus binds on the standard port
 RUN find /opt /usr /etc /home -name "*.xml" -exec sed -i 's/<port>5020<\/port>/<port>502<\/port>/g' {} + 2>/dev/null || true
 RUN find /opt /usr /etc /home -name "*.xml" -exec sed -i 's/port="5020"/port="502"/g' {} + 2>/dev/null || true
 
-# Install libcap to allow binding to 502
+# Install libcap and give the Python interpreter permission to bind ports < 1024
 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
 
-# Apply setcap to python binaries
-RUN find /usr /opt -type f -name 'python*' -exec setcap 'cap_net_bind_service+eip' {} \; 2>/dev/null || true
-
-# Create the decnet user following repository conventions
-RUN (addgroup -S decnet && adduser -S decnet -G decnet 2>/dev/null) || useradd -r -s /bin/false decnet 2>/dev/null || true
-
-# Make sure all conpot-related directories are owned by decnet so it can run it
-RUN chown -R decnet:decnet /var/log/conpot /opt/conpot /home/conpot /usr/local/lib/python*/site-packages/conpot/tests/data /tmp 2>/dev/null || true
-
-# Run as decnet user, avoiding the root-check failure and 777 hacks
-USER decnet
+# 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'.
+USER conpot