Configure server cache time from the command line (--cached-time) #901 / Also implement cache time for the Web server mode

NEWS

@@ -10,6 +10,7 @@ Enhancements and new features:
     * Add CouchDB exporter (issue #928)
     * Highlight max stats in the processes list (issue #878)
     * Glances API returns the processes PPID (issue #926)
+    * Configure server cached time from the command line --cached-time (issue #901)
 
 Bugs corrected:
 

glances/__init__.py

@@ -168,12 +168,12 @@ def main():
         from glances.server import GlancesServer
 
         args = core.get_args()
+        print args.cached_time
 
-        server = GlancesServer(cached_time=core.cached_time,
+        server = GlancesServer(cached_time=args.cached_time,
                                config=core.get_config(),
                                args=args)
         print('Glances server is running on {}:{}'.format(args.bind_address, args.port))
-
         # Set the server login/password (if -P/--password tag)
         if args.password != "":
             server.add_user(args.username, args.password)

glances/main.py

@@ -25,7 +25,7 @@ import sys
 import tempfile
 
 from glances import __appname__, __version__, psutil_version
-from glances.compat import input
+from glances.compat import input, NoOptionError, NoSectionError
 from glances.config import Config
 from glances.globals import LINUX, WINDOWS
 from glances.logger import logger
@@ -37,9 +37,7 @@ class GlancesMain(object):
 
     # Default stats' refresh time is 3 seconds
     refresh_time = 3
-
     # Set the default cache lifetime to 1 second (only for server)
-    # !!! Todo: To be configurable (=> https://github.com/nicolargo/glances/issues/901)
     cached_time = 1
     # By default, Glances is ran in standalone mode (no client/server)
     client_tag = False
@@ -83,6 +81,7 @@ Start the client browser (browser mode):\n\
 
     def __init__(self):
         """Manage the command line arguments."""
+        # Read the command line arguments
         self.args = self.parse_args()
 
     def init_args(self):
@@ -210,6 +209,8 @@ Start the client browser (browser mode):\n\
                             dest='time', help='set refresh time in seconds [default: {} sec]'.format(self.refresh_time))
         parser.add_argument('-w', '--webserver', action='store_true', default=False,
                             dest='webserver', help='run Glances in web server mode (bottle needed)')
+        parser.add_argument('--cached-time', default=self.cached_time, type=int,
+                            dest='cached_time', help='set the server cache time [default: {} sec]'.format(self.cached_time))
         # Display options
         parser.add_argument('-q', '--quiet', default=False, action='store_true',
                             dest='quiet', help='do not display the curses interface')

glances/outputs/glances_bottle.py

@@ -25,6 +25,7 @@ import sys
 import tempfile
 from io import open
 
+from glances.timer import Timer
 from glances.logger import logger
 
 try:
@@ -46,6 +47,11 @@ class GlancesBottle(object):
         # Will be updated within Bottle route
         self.stats = None
 
+        # cached_time is the minimum time interval between stats updates
+        # i.e. HTTP/Restful calls will not retrieve updated info until the time
+        # since last update is passed (will retrieve old cached info instead)
+        self.timer = Timer(0)
+
         # Init Bottle
         self._app = Bottle()
         # Enable CORS (issue #479)
@@ -59,6 +65,12 @@ class GlancesBottle(object):
         # Path where the statics files are stored
         self.STATIC_PATH = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'static/public')
 
+    def __update__(self):
+        # Never update more than 1 time per cached_time
+        if self.timer.finished():
+            self.stats.update()
+            self.timer = Timer(self.args.cached_time)
+
     def app(self):
         return self._app()
 
@@ -117,7 +129,7 @@ class GlancesBottle(object):
     def _index(self, refresh_time=None):
         """Bottle callback for index.html (/) file."""
         # Update the stat
-        self.stats.update()
+        self.__update__()
 
         # Display
         return static_file("index.html", root=self.STATIC_PATH)
@@ -170,7 +182,7 @@ class GlancesBottle(object):
         response.content_type = 'application/json'
 
         # Update the stat
-        self.stats.update()
+        self.__update__()
 
         try:
             plist = json.dumps(self.plugins_list)
@@ -197,7 +209,7 @@ class GlancesBottle(object):
                 logger.debug("Debug file (%s) not found" % fname)
 
         # Update the stat
-        self.stats.update()
+        self.__update__()
 
         try:
             # Get the JSON value of the stat ID
@@ -254,7 +266,7 @@ class GlancesBottle(object):
             abort(400, "Unknown plugin %s (available plugins: %s)" % (plugin, self.plugins_list))
 
         # Update the stat
-        self.stats.update()
+        self.__update__()
 
         try:
             # Get the JSON value of the stat ID
@@ -278,7 +290,7 @@ class GlancesBottle(object):
             abort(400, "Unknown plugin %s (available plugins: %s)" % (plugin, self.plugins_list))
 
         # Update the stat
-        self.stats.update()
+        self.__update__()
 
         try:
             # Get the JSON value of the stat ID
@@ -301,7 +313,7 @@ class GlancesBottle(object):
             abort(400, "Unknown plugin %s (available plugins: %s)" % (plugin, self.plugins_list))
 
         # Update the stat
-        # self.stats.update()
+        # self.__update__()
 
         try:
             # Get the JSON value of the stat limits
@@ -324,7 +336,7 @@ class GlancesBottle(object):
             abort(400, "Unknown plugin %s (available plugins: %s)" % (plugin, self.plugins_list))
 
         # Update the stat
-        # self.stats.update()
+        # self.__update__()
 
         try:
             # Get the JSON value of the stat views
@@ -341,7 +353,7 @@ class GlancesBottle(object):
             abort(400, "Unknown plugin %s (available plugins: %s)" % (plugin, self.plugins_list))
 
         # Update the stat
-        self.stats.update()
+        self.__update__()
 
         if value is None:
             if history: