Update Dockerfile

Dockerfile

@@ -10,7 +10,17 @@ WORKDIR /tmp/napalm-onyx
 RUN /opt/netbox/venv/bin/pip3 install pip==20.0.2 && \
     /opt/netbox/venv/bin/pip3 install . && \
     rm -rf /tmp/napalm-onyx
-RUN adduser -k --uid 1000 netbox
+
+ENV USER=netbox
+ENV UID=1000
+
+RUN adduser \
+    --disabled-password \
+    --gecos "" \
+    --ingroup "$USER" \
+    --uid "$UID" \
+    "$USER"
+
 USER netbox
 RUN SECRET_KEY="dummy" /opt/netbox/venv/bin/python /opt/netbox/netbox/manage.py collectstatic --no-input