beremiz

fix problem when Beremiz is running without matiec installed

2017-08-25, Andrey Skvortsov
492e2cd6157e
fix problem when Beremiz is running without matiec installed

set matiec settings only once on first use of ProjectController class and give
user-friendly message on compilation about missing matiec
installation.


Traceback (most recent call last):
File "Beremiz.py", line 197, in
beremiz.Start()
File "Beremiz.py", line 192, in Start
self.CreateApplication()
File "Beremiz.py", line 130, in CreateApplication
self.BackgroundInitialization()
File "Beremiz.py", line 137, in BackgroundInitialization
self.ImportModules()
File "Beremiz.py", line 176, in ImportModules
import BeremizIDE
File
"BeremizIDE.py", line 76, in
from ProjectController import ProjectController, GetAddMenuItems,
MATIEC_ERROR_MODEL, ITEM_CONFNODE
File
"ProjectController.py", line 177, in
iec2c_cfg = Iec2CSettings()
File
"ProjectController.py", line 101, in __init__
self.ieclib_c_path = self.findLibCPath()
File
"ProjectController.py", line 135, in findLibCPath
os.path.join(self.ieclib_path, "C"),
File "/usr/lib/python2.7/posixpath.py", line 70, in join
elif path == '' or path.endswith('/'):
AttributeError: 'NoneType' object has no attribute 'endswith'
Beremiz and Beremiz_service connectors
======================================
To connect a PLC, Beremiz provides 2 types of connectors :
* a Pyro connector
* a WAMP connector
To configure the connection, you have to set the *URI_location* in your project Config tab according to this documentation.
The Pyro connector
----------------------------
Pyro is an advanced and powerful Distributed Object Technology system written entirely in Python.
Beremiz_service spawns a Pyro server, serving a PLCObject (see runtime/PLCObject.py). Therefore, Beremiz acts as a Pyro client.
TODO:: link to PLCObject API documentation
URI_location :
* LOCAL:// is a facility that starts the PLC service locally and connect Beremiz to it via Pyro.
This is intended for use in development stage.
* PYRO://<ip:port> normal connection to a remote PLC. PLC default port is 3000.
* PYROS://<ip:port> SSL connection to a remote PLC, see below.
more information about Pyro can be found on http://pythonhosted.org//Pyro/1-intro.html
===========================
Setup a Pyro SSL connection
===========================
Pyro v3 has a limited TLS/SSL support based on m2crypto. Pyro v4 had dropped it.
In order to have a full and reliable SSL, we recommand to use a TLS/SSL wrapper as nginx, stub or stunnel.
--------------------
TLS-PSK with stunnel
--------------------
In this example, we setup a simple TLS-PSK connection according to rfc4279.
This ciphersuite avoid the need for public key operations and certificate management.
It is perfect for a performance-constrained environments with limited CPU power as a PLC.
Needed :
* stunnel >= 5.09
verify openssl support for PSK cipher::
openssl ciphers -v 'PSK'
----------------------
Client setup (Beremiz)
----------------------
You need to choose an identity for your client, here *client1*.
generate a valid and strong key::
$ echo client1:$(openssl rand -base64 48) > pskclient1.txt
write a stunnel client configuration file *stunnel-client.conf*::
output = stunnel-client.log
client = yes
[beremiz]
accept = 3002
connect = [PLC]:3001
PSKidentity = client1
PSKsecrets = pskclient1.txt
start stunnel client side::
stunnel stunnel-client.conf
You could now connect beremiz with classic URI_location = PYRO://127.0.0.1:3002
--------------------
Server setup (PLC)
--------------------
import the client key in a keyfile psk.txt, concatening all client key.
write a stunnel server configuration file *stunnel-server.conf*::
output = stunnel-server.log
[beremiz]
accept = 3001
connect = 127.0.0.1:3000
PSKsecrets = psk.txt
start stunnel server side::
stunnel stunnel-server.conf
more documentation on stunnel http://www.stunnel.org/docs.html
The WAMP connector
------------------
WAMP is an open standard WebSocket subprotocol that provides two application messaging
patterns in one unified protocol: Remote Procedure Calls + Publish & Subscribe.
Beremiz WAMP connector implementation uses Autobahn and crossbar.
URI_location :
* WAMP://127.0.0.1:8888#Automation#2534667845
more information about WAMP can be found on http://wamp.ws/