Feature/modbus udp (#43)

* Upgrade Dependencies, expose also UDP port and increase version

* Upgrade pre-commit framework and linters

* Adding protocol

* Add new Version and describe new protocol parameter

* Adding protocol

* Add UDP mode

* fix start message

* Adding udp example

Author: cybcon

.pre-commit-config.yaml

@@ -1,28 +1,44 @@
+
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.4.0
+    rev: v5.0.0
     hooks:
+      - id: fix-byte-order-marker
       - id: check-ast
       - id: check-json
+      - id: check-yaml
       - id: debug-statements
       - id: end-of-file-fixer
+      - id: trailing-whitespace
       - id: fix-encoding-pragma
-      - id: mixed-line-ending
       - id: requirements-txt-fixer
-      - id: trailing-whitespace
+      - id: mixed-line-ending
+        args: ['--fix=lf']
+        description: Forces to replace line ending by the UNIX 'lf' character
+      - id: detect-aws-credentials
+        args: ['--allow-missing-credentials']
+      - id: detect-private-key
+  - repo: https://github.com/myint/autoflake
+    rev: v2.3.1
+    hooks:
+      - id: autoflake
+        args:
+          - --in-place
+          - --remove-unused-variables
+          - --remove-all-unused-imports
   - repo: https://github.com/hadolint/hadolint
     rev: v2.12.0
     hooks:
       - id: hadolint-docker
-  - repo: 'https://github.com/charliermarsh/ruff-pre-commit'
-    rev: v0.2.0
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
+    rev: v0.7.0
     hooks:
       - id: ruff
         args:
           - '--line-length=120'
           - '--fix'
           - '--exit-non-zero-on-fix'
-  - repo: 'https://github.com/pycqa/isort'
+  - repo: https://github.com/pycqa/isort
     rev: 5.13.2
     hooks:
       - id: isort
@@ -31,8 +47,8 @@ repos:
           - '--profile'
           - black
           - '--filter-files'
-  - repo: 'https://github.com/psf/black'
-    rev: 24.1.1
+  - repo: https://github.com/psf/black
+    rev: 24.10.0
     hooks:
       - id: black
         args:

.tool-versions

@@ -1 +1,2 @@
-pre-commit 3.7.1
+python 3.11.4
+pre-commit 4.0.1

Dockerfile

@@ -1,11 +1,11 @@
-FROM alpine:3.20.1
+FROM alpine:3.20.3
 
 LABEL maintainer="Michael Oberdorf IT-Consulting <info@oberdorf-itc.de>"
-LABEL site.local.program.version="1.3.2"
+LABEL site.local.program.version="1.4.0"
 
 RUN apk upgrade --available --no-cache --update \
     && apk add --no-cache --update \
-       python3=3.12.3-r1 \
+       python3=3.12.7-r0 \
        py3-pip=24.0-r2 \
     # Cleanup APK
     && rm -rf /var/cache/apk/* /tmp/* /var/tmp/*
@@ -15,6 +15,7 @@ COPY --chown=root:root /src /
 RUN pip3 install --no-cache-dir -r /requirements.txt --break-system-packages
 
 EXPOSE 5020/tcp
+EXPOSE 5020/udp
 
 USER 1434:1434
 

Dockerfile.test

@@ -1,11 +1,11 @@
-FROM alpine:3.20.1
+FROM alpine:3.20.3
 
 LABEL maintainer="Michael Oberdorf IT-Consulting <info@oberdorf-itc.de>"
-LABEL site.local.program.version="1.3.2"
+LABEL site.local.program.version="1.4.0"
 
 RUN apk upgrade --available --no-cache --update \
     && apk add --no-cache --update \
-       python3=3.12.3-r1 \
+       python3=3.12.7-r0 \
        py3-pip=24.0-r2 \
     # Cleanup APK
     && rm -rf /var/cache/apk/* /tmp/* /var/tmp/*
@@ -16,6 +16,7 @@ COPY --chown=root:root /examples/test.json /test.json
 RUN pip3 install --no-cache-dir -r /requirements.txt --break-system-packages
 
 EXPOSE 5020/tcp
+EXPOSE 5020/udp
 
 USER 1434:1434
 

README.md

@@ -23,7 +23,8 @@ Container image: [DockerHub](https://hub.docker.com/r/oitc/modbus-server)
 
 # Supported tags and respective `Dockerfile` links
 
-* [`latest`, `1.3.2`](https://github.com/cybcon/modbus-server/blob/v1.3.2/Dockerfile)
+* [`latest`, `1.4.0`](https://github.com/cybcon/modbus-server/blob/v1.4.0/Dockerfile)
+* [`1.3.2`](https://github.com/cybcon/modbus-server/blob/v1.3.2/Dockerfile)
 * [`1.3.1`](https://github.com/cybcon/modbus-server/blob/v1.3.1/Dockerfile)
 * [`1.3.0`](https://github.com/cybcon/modbus-server/blob/v1.3.0/Dockerfile)
 * [`1.2.0`](https://github.com/cybcon/modbus-server/blob/v1.2.0/Dockerfile)
@@ -92,6 +93,7 @@ The `/app/modbus_server.json` file comes with following content:
 "server": {
   "listenerAddress": "0.0.0.0",
   "listenerPort": 5020,
+  "protocol": "TCP",
   "tlsParams": {
     "description": "path to certificate and private key to enable tls",
     "privateKey": null,
@@ -120,7 +122,8 @@ The `/app/modbus_server.json` file comes with following content:
 |------------------------------------------|---------|-----------------------------------------------------------------------------------------------------------------------|
 | `server`                                 | Object  | Modbus slave specific runtime parameters.                                                                             |
 | `server.listenerAddress`                 | String  | The IPv4 Address to bound to when starting the server. `"0.0.0.0"` let the server listens on all interface addresses. |
-| `server.listenerPort`                    | Integer | The TCP port number of the modbus slave to listen to.                                                                 |
+| `server.listenerPort`                    | Integer | The port number of the modbus slave to listen to.                                                                     |
+| `server.protocol`                        | String  | Defines if the server should use `TCP` or `UDP` (default: `TCP`)                                                      |
 | `server.tlsParams`                       | Object  | Configuration parameters to use TLS encrypted modbus tcp slave. (untested)                                            |
 | `server.tlsParams.description`           | String  | No configuration option, just a description of the parameters.                                                        |
 | `server.tlsParams.privateKey`            | String  | Filesystem path of the private key to use for a TLS encrypted communication.                                          |
@@ -176,6 +179,7 @@ Example configuration of pre-defined registers from type "Holding Registers" or
 - [src/app/modbus_server.json](https://github.com/cybcon/modbus-server/blob/main/src/app/modbus_server.json)
 - [examples/abb_coretec_example.json](https://github.com/cybcon/modbus-server/blob/main/examples/abb_coretec_example.json)
 - [examples/test.json](https://github.com/cybcon/modbus-server/blob/main/examples/test.json)
+- [examples/udp.json](https://github.com/cybcon/modbus-server/blob/main/examples/udp.json)
 
 
 

examples/abb_coretec_example.json

@@ -2,6 +2,7 @@
 "server": {
   "listenerAddress": "0.0.0.0",
   "listenerPort": 1503,
+  "protocol": "TCP",
   "tlsParams": {
     "description": "path to certificate and private key to enable tls",
     "privateKey": null,

examples/test.json

@@ -2,6 +2,7 @@
 "server": {
   "listenerAddress": "0.0.0.0",
   "listenerPort": 5020,
+  "protocol": "TCP",
   "tlsParams": {
     "description": "path to certificate and private key to enable tls",
     "privateKey": null,

examples/udp.json

@@ -0,0 +1,45 @@
+{
+"server": {
+  "listenerAddress": "0.0.0.0",
+  "listenerPort": 5020,
+  "protocol": "UDP",
+  "tlsParams": {
+    "description": "path to certificate and private key to enable tls",
+    "privateKey": null,
+    "certificate": null
+    },
+  "logging": {
+    "format": "%(asctime)-15s %(threadName)-15s  %(levelname)-8s %(module)-15s:%(lineno)-8s %(message)s",
+    "logLevel": "DEBUG"
+    }
+  },
+"registers": {
+  "description": "initial values for the register types",
+  "zeroMode": false,
+  "initializeUndefinedRegisters": true,
+  "discreteInput": {
+    "1": true,
+    "2": false,
+    "3": true,
+    "4": false
+  },
+  "coils": {
+    "1": false,
+    "2": true,
+    "3": true,
+    "4": false
+  },
+  "holdingRegister": {
+    "1": 52225,
+    "2": "0xCC02",
+    "3": 52227,
+    "4": "0xCC04"
+    },
+  "inputRegister": {
+    "1": "0xDD01",
+    "2": 56578,
+    "3": "0xDD03",
+    "4": 56580
+    }
+  }
+}

src/app/modbus_server.json

@@ -2,6 +2,7 @@
 "server": {
   "listenerAddress": "0.0.0.0",
   "listenerPort": 5020,
+  "protocol": "TCP",
   "tlsParams": {
     "description": "path to certificate and private key to enable tls",
     "privateKey": null,

src/app/modbus_server.py

@@ -4,7 +4,7 @@
 Author: Michael Oberdorf IT-Consulting
 Datum: 2020-03-30
 Last modified by: Michael Oberdorf
-Last modified at: 2024-07-19
+Last modified at: 2024-10-22
 *************************************************************************** """
 import argparse
 import json
@@ -21,11 +21,11 @@
     ModbusSparseDataBlock,
 )
 from pymodbus.device import ModbusDeviceIdentification
-from pymodbus.server.sync import StartTcpServer, StartTlsServer
+from pymodbus.server.sync import StartTcpServer, StartTlsServer, StartUdpServer
 
 # default configuration file path
 default_config_file = "/app/modbus_server.json"
-VERSION = "1.3.2"
+VERSION = "1.4.0"
 
 log = logging.getLogger()
 
@@ -55,6 +55,7 @@ def get_ip_address() -> str:
 def run_server(
     listener_address: str = "0.0.0.0",
     listener_port: int = 5020,
+    protocol: str = "TCP",
     tls_cert: str = None,
     tls_key: str = None,
     zero_mode: bool = False,
@@ -67,6 +68,7 @@ def run_server(
     Run the modbus server(s)
     @param listener_address: string, IP address to bind the listener (default: '0.0.0.0')
     @param listener_port: integer, TCP port to bin the listener (default: 5020)
+    @param protocol: string, defines if the server listenes to TCP or UDP (default: 'TCP')
     @param tls_cert: boolean, path to certificate to start tcp server with TLS (default: None)
     @param tls_key: boolean, path to private key to start tcp server with TLS (default: None)
     @param zero_mode: boolean, request to address(0-7) will map to the address (0-7) instead of (1-8) (default: False)
@@ -157,10 +159,14 @@ def run_server(
             address=(listener_address, listener_port),
         )
     else:
-        log.info(f"Starting Modbus TCP server on {listener_address}:{listener_port}")
-        StartTcpServer(context, identity=identity, address=(listener_address, listener_port))
-        # TCP with different framer
-        # StartTcpServer(context, identity=identity, framer=ModbusRtuFramer, address=(listener_address, listener_port))
+        if protocol == "UDP":
+            log.info(f"Starting Modbus UDP server on {listener_address}:{listener_port}")
+            StartUdpServer(context, identity=identity, address=(listener_address, listener_port))
+        else:
+            log.info(f"Starting Modbus TCP server on {listener_address}:{listener_port}")
+            StartTcpServer(context, identity=identity, address=(listener_address, listener_port))
+            # TCP with different framer
+            # StartTcpServer(context, identity=identity, framer=ModbusRtuFramer, address=(listener_address, listener_port))
 
 
 def prepare_register(
@@ -281,7 +287,7 @@ def prepare_register(
     logging.basicConfig(format=CONFIG["server"]["logging"]["format"])
 
     # start the server
-    log.info(f"Starting Modbus TCP Server, v{VERSION}")
+    log.info(f"Starting Modbus Server, v{VERSION}")
     log.debug(f"Loaded successfully the configuration file: {config_file}")
 
     # be sure the data types within the dictionaries are correct (json will only allow strings as keys)
@@ -306,13 +312,18 @@ def prepare_register(
         initialize_undefined_registers=CONFIG["registers"]["initializeUndefinedRegisters"],
     )
 
+    # add TCP protocol to configuration if not defined
+    if "protocol" not in CONFIG["server"]:
+        CONFIG["server"]["protocol"] = "TCP"
+
     # try to get the interface IP address
     local_ip_addr = get_ip_address()
     if local_ip_addr != "":
         log.info(f"Outbound device IP address is: {local_ip_addr}")
     run_server(
         listener_address=CONFIG["server"]["listenerAddress"],
         listener_port=CONFIG["server"]["listenerPort"],
+        protocol=CONFIG["server"]["protocol"],
         tls_cert=CONFIG["server"]["tlsParams"]["privateKey"],
         tls_key=CONFIG["server"]["tlsParams"]["certificate"],
         zero_mode=CONFIG["registers"]["zeroMode"],