feat!: replace zerorpc with pyro4 for communication between clients a…

…nd agent

zerorpc-python is not actively maintained (repository last updated 4 years ago):
switch to pyro4 since it shares many of the concepts found in zerorpc (very few
changes were required to move from one to another). Both Debian and Ubuntu ship
python3-pyro4 packages.

BREAKING CHANGE: clients running an older version of MTDA based on zerorpc will
not be able to communicate with a server using pyro4.

Signed-off-by: Cedric Hombourger <[email protected]>

.reuse/dep5

@@ -91,14 +91,6 @@ Files: meta-isar/recipes-python/qt5/files/py3qterm-0.4/debian/*
 Copyright: 2025 Siemens AG
 License: MIT
 
-Files: meta-isar/recipes-python/zerorpc/files/zerorpc-0.6.3/debian/*
-Copyright: 2025 Siemens AG
-License: MIT
-
-Files: meta-isar/recipes-python/zerorpc/files/zerorpc-0.6.3/debian/source/*
-Copyright: 2025 Siemens AG
-License: MIT
-
 Files: meta-isar/recipes-bsp/rpi-firmware/files/*
 Copyright: 2025 Siemens AG
 License: MIT

debian/control

@@ -69,7 +69,7 @@ Package: mtda-common
 Architecture: all
 Multi-Arch: foreign
 Depends: python3:any (>= 3.7~),
-         python3-zerorpc
+         python3-pyro4
 Description: common modules for Multi-Tenant Device Access
  Modules shared between the service and the client.
 

debian/py3dist-overrides

@@ -1,4 +1,3 @@
 kconfiglib python3-kconfiglib
 requests python3-requests
-zerorpc python3-zerorpc
 zstandard python3-zstandard

meta-isar/recipes-python/mtda/mtda_git.bb

@@ -35,7 +35,7 @@ SRC_URI += "${@' '.join(['file://' + d.getVar('LAYERDIR_mtda') + '/../' + file f
 
 S = "${WORKDIR}/working-repo"
 
-DEPENDS += "zerorpc-python py3qterm"
+DEPENDS += "py3qterm"
 
 do_gen_working_repo() {
 	for file in ${MTDA_FILES}; do

mtda-cli

@@ -14,7 +14,6 @@
 import requests
 import time
 import sys
-import zerorpc
 import socket
 from argparse import ArgumentParser, RawTextHelpFormatter
 
@@ -410,13 +409,7 @@ class Application:
         uptime = ""
         if tgt_status == "ON":
             uptime = f" (up {self.target_uptime()})"
-        try:
-            remote_version = client.agent_version()
-        except (zerorpc.RemoteError) as e:
-            if e.name == 'NameError':
-                remote_version = "<=0.5"
-            else:
-                raise e
+        remote_version = client.agent_version()
 
         host = MultiTenantDeviceAccess()
         prefix_key = chr(ord(client.console_prefix_key()) + ord('a') - 1)

mtda-service

@@ -17,9 +17,9 @@ import lockfile
 import netifaces
 import os
 import os.path
+import Pyro4
 import signal
 import sys
-import zerorpc
 import socket
 import zeroconf
 from systemd import daemon as sd
@@ -75,9 +75,10 @@ class Application:
             return False
 
         # Start our RPC server
-        uri = "tcp://*:%d" % (self.agent.ctrlport)
-        s = zerorpc.Server(self.agent, heartbeat=20)
-        s.bind(uri)
+        Pyro4.config.HOST = "0.0.0.0"
+        Pyro4.config.SERIALIZER = "marshal"
+        daemon = Pyro4.Daemon(port=self.agent.ctrlport)
+        daemon.register(self.agent, objectId="mtda.main")
 
         # Initialize ZeroConf
         interfaces = zeroconf.InterfaceChoice.All
@@ -105,7 +106,7 @@ class Application:
 
         try:
             sd.notify('READY=1')
-            s.run()
+            daemon.requestLoop()
         except KeyboardInterrupt:
             self.stop()
         return True

mtda/client.py

@@ -11,12 +11,12 @@
 
 
 import os
+import Pyro4
 import random
 import socket
 import subprocess
 import tempfile
 import time
-import zerorpc
 import zstandard as zstd
 
 from mtda.main import MultiTenantDeviceAccess
@@ -37,11 +37,10 @@ def __init__(self, host=None, session=None, config_files=None,
         agent = MultiTenantDeviceAccess()
         agent.load_config(host, config_files=config_files)
         if agent.remote is not None:
-            uri = "tcp://%s:%d" % (agent.remote, agent.ctrlport)
-            self._impl = zerorpc.Client(
-                heartbeat=min(timeout, CONSTS.RPC.HEARTBEAT),
-                timeout=timeout)
-            self._impl.connect(uri)
+            uri = f"PYRO:mtda.main@{agent.remote}:{agent.ctrlport}"
+            Pyro4.config.SERIALIZER = "marshal"
+            self._impl = Pyro4.Proxy(uri)
+            self._impl._pyroTimeout = timeout
         else:
             self._impl = agent
         self._agent = agent

mtda/constants.py

@@ -52,7 +52,6 @@ class POWER:
 
 
 class RPC:
-    HEARTBEAT = 20
     TIMEOUT = 2*60