Added Settings and Python Logging

README.md

@@ -1,5 +1,5 @@
 
-Copyright (C) 2014-2015 Jaguar Land Rover
+Copyright (C) 2015,2016 Jaguar Land Rover
 
 This document is licensed under Creative Commons
 Attribution-ShareAlike 4.0 International.
@@ -117,23 +117,68 @@ LocMedMgr | Local Media Manager
 
 
 
-# RUNNING THE CODE ON UBUNTU 14.10 AND 15.10
+# INSTALLATION AND CONFIGURATION
 
-## Install python and add ons.
+## Installation on Debian and Ubuntu
 
 Make sure you have Python 2.7 (or later 2.X) installed.
 
 Install the necessary python libraries
 
-    sudo apt-get install python-gtk2
+    sudo apt-get install python-gtk2 python-storm
 
+## Installation on Fedora
+
+Make sure you have Python 2.7 (or later 2.X) installed.
+
+Install the necessary python libraries
+
+    sudo dnf install python-gtk2 python-storm
+
+## Configuration (All Distributions)
+
+All configuration is accomplished by changing the configuration variables in ```common/settings.py```. 
+
+Common settings are:
+
+* SWM_SIMULATION:
+  If set to ```True``` SWM runs in simulation mode. In this mode FUSE and
+  squashfuse are used to mount the SquashFS archive containing the update.
+  If set to ```False``` SWM must be run as root.
+
+* SWM_SIMULATION_WAIT:
+  Time in seconds to wait for simulated operations.
+
+* DB_URL:
+  SWM maintains update information in a SQLite database. This variable sets
+  path and name of the database file.
+
+* LOGGER:
+  The standard logger is ```swm.default```, which outputs logging information
+  to the console and to the file specified by ```LOGFILE```. Other loggers are
+  ```swm.console``` which outputs to the console only and ```swm.file``` which
+  outputs to a log file only.
+
+* LOGFILE:
+  Path and name to the log file.
+
+
+# RUNNING
 
-## Launch SWM components
 In a terminal window, run a fully automated demo using:
 
     sudo sh start_swm.sh -r 
 
-```sudo``` is needed since the sample_update.upd file is a squashfs image that needs to be mounted.
+```sudo``` is needed only if running in *real mode* with ```SWM_SIMULATION = False``` in ```common/settings.py```.
+
+**WARNING:** When running in *real mode* SWM attempts to install the software package nano on the system. The
+```start_swm.sh``` script figures out what distribution it is running on and chooses an RPM (Fedora) or DEB (Debian and Ubuntu)
+software update to execute.
+
+When running in *simulation mode*, you need to have Filesystem in User Space (FUSE) and squashfuse installed on your system.
+FUSE is standard for virtually all Linux distributions, including Debian, Fedora and Ubuntu. squashfuse is not a standard
+package and the distributions do not have it in their repositories. However, it can easily be compiled from source which can
+be found at https://github.com/vasi/squashfuse.
 
 ```-r``` Specifies that the database storing already processed software operations (hosted in an update) should
 be reset. If that is not done, subsequent runs will all return "Already processed"
@@ -145,8 +190,14 @@ and control the actions.
 Each launched component will get their own terminal window.
 
 ## Watch execution
-The system will execute the manifest from ```sample_update/update_manifest.json```, stored in the
-```sample_update.upd``` squashfs image of the ```sample_update``` directory.
+When running in *simulation mode* the system will execute the manifest from ```sample_update/update_manifest.json```,
+stored in the ```sample_update.upd``` squashfs image of the ```sample_update``` directory.
+
+When running in *real mode* the system will determine what distribution it is running on and then:
+* if running on Fedora, execute the manifest from ```rpm_update/update_manifest.json```, stored in the ```rpm_update.upd```
+  squashfs image of the ```rpm_update``` directory;
+* if running on Debian or Ubuntu, execute the manifest from ```deb_update/update_manifest.json```, stored in the ```deb_update.upd```
+  squashfs image of the ```deb_update``` directory.
 
 During the execution the HMI window will show an overall progress bar and a progress bar for each
 software operation carried out.

common/daemon.py

@@ -0,0 +1,145 @@
+"""
+Copyright (C) 2014, Jaguar Land Rover
+
+This program is licensed under the terms and conditions of the
+Mozilla Public License, version 2.0.  The full text of the 
+Mozilla Public License is at https://www.mozilla.org/MPL/2.0/
+
+Adapted from http://www.jejik.com/articles/2007/02/a_simple_unix_linux_daemon_in_python/
+
+Maintainer: Rudolf Streif ([email protected]) 
+"""
+
+"""
+Base class to create Linux daemons.
+"""
+
+import os, sys, atexit, time
+from signal import *
+
+
+class Daemon(object):
+    """
+    A generic daemon class.
+    Usage: subclass the Daemon class and override the run() method
+    """
+    def __init__(self, pidfile, stdin='/dev/null', stdout='/dev/null', stderr='/dev/null'):
+        self.stdin = stdin
+        self.stdout = stdout
+        self.stderr = stderr
+        self.pidfile = pidfile
+
+    def daemonize(self):
+        """
+        do the UNIX double-fork magic, see Stevens' "Advanced
+        Programming in the UNIX Environment" for details (ISBN 0201563177)
+        http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16
+         """
+        try:
+            pid = os.fork()
+            if pid > 0:
+                # exit first parent
+                sys.exit(0)
+        except OSError, e:
+            sys.stderr.write("Daemon: Fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
+            sys.exit(1)
+
+        # decouple from parent environment
+        os.chdir("/")
+        os.setsid()
+        os.umask(0)
+
+        # do second fork
+        try:
+            pid = os.fork()
+            if pid > 0:
+                # exit from second parent
+                sys.exit(0)
+        except OSError, e:
+            sys.stderr.write("Daemon: Fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
+            sys.exit(1)
+
+        # redirect standard file descriptors
+        sys.stdout.flush()
+        sys.stderr.flush()
+        si = file(self.stdin, 'r')
+        so = file(self.stdout, 'a+')
+        se = file(self.stderr, 'a+', 0)
+        os.dup2(si.fileno(), sys.stdin.fileno())
+        os.dup2(so.fileno(), sys.stdout.fileno())
+        os.dup2(se.fileno(), sys.stderr.fileno())
+
+        # write pidfile
+        atexit.register(self.delpid)
+        pid = str(os.getpid())
+        file(self.pidfile,'w+').write("%s\n" % pid)
+
+    def delpid(self):
+        os.remove(self.pidfile)
+
+    def start(self):
+         """
+         Start the daemon
+         """
+         # Check for a pidfile to see if the daemon already runs
+         try:
+             pf = file(self.pidfile,'r')
+             pid = int(pf.read().strip())
+             pf.close()
+         except IOError:
+              pid = None
+
+         if pid:
+             message = "Daemon: Pidfile %s already exist. Daemon already running?\n"
+             sys.stderr.write(message % self.pidfile)
+             sys.exit(1)
+
+         # Start the daemon
+         self.daemonize()
+         self.run()
+
+    def stop(self):
+        """
+        Stop the daemon
+        """
+        # Get the pid from the pidfile
+        try:
+            pf = file(self.pidfile,'r')
+            pid = int(pf.read().strip())
+            pf.close()
+        except IOError:
+            pid = None
+
+        if not pid:
+            message = "Daemon: Pidfile %s does not exist. Daemon not running?\n"
+            sys.stderr.write(message % self.pidfile)
+            return # not an error in a restart
+
+        # Try killing the daemon process       
+        try:
+            while 1:
+                os.kill(pid, SIGTERM)
+                time.sleep(0.1)
+        except OSError, err:
+            err = str(err)
+            if err.find("No such process") > 0:
+                if os.path.exists(self.pidfile):
+                    os.remove(self.pidfile)
+            else:
+                message = "Daemon: Error shutting down: %s\n"
+                sys.stderr.write(message % err)
+                sys.exit(1)
+
+    def restart(self):
+        """
+        Restart the daemon
+        """
+        self.stop()
+        self.start()
+
+    def run(self):
+        """
+        You should override this method when you subclass Daemon. It will be called after the process has been
+        daemonized by start() or restart().
+        """
+