Add rotation capable logging tool for customized ansible modules

ansible/library/conn_graph_facts.py

@@ -3,6 +3,7 @@
 import lxml.etree as ET
 import yaml
 import os
+import logging
 import traceback
 import ipaddr as ipaddress
 from operator import itemgetter
@@ -12,13 +13,17 @@
 
 try:
     from ansible.module_utils.port_utils import get_port_alias_to_name_map
-    from ansible.module_utils.debug_utils import create_debug_file, print_debug_msg
+    from ansible.module_utils.debug_utils import config_module_logging
 except ImportError:
     # Add parent dir for using outside Ansible
     import sys
     sys.path.append('..')
     from module_utils.port_utils import get_port_alias_to_name_map
-    from module_utils.debug_utils import create_debug_file, print_debug_msg
+    from module_utils.debug_utils import config_module_logging
+
+
+config_module_logging('conn_graph_facts')
+
 
 DOCUMENTATION='''
 module: conn_graph_facts.py
@@ -105,9 +110,6 @@
 '''
 
 
-debug_fname = None
-
-
 class Parse_Lab_Graph():
     """
     Parse the generated lab physical connection graph and insert Ansible fact of the graph
@@ -263,8 +265,8 @@ def parse_graph(self):
                     for pdulink in allpdulinks:
                         start_dev = pdulink.attrib['StartDevice']
                         end_dev = pdulink.attrib['EndDevice']
-                        print_debug_msg(debug_fname, "pdulink {}".format(pdulink.attrib))
-                        print_debug_msg(debug_fname, "self.pdulinks {}".format(self.pdulinks))
+                        logging.debug("pdulink {}".format(pdulink.attrib))
+                        logging.debug("self.pdulinks {}".format(self.pdulinks))
                         if start_dev:
                             if start_dev not in self.pdulinks:
                                 self.pdulinks.update({start_dev : {}})
@@ -417,20 +419,19 @@ def find_graph(hostnames, part=False):
         hostnames: list of duts in the target testbed.
         part: select the graph file if over 80% of hosts are found in conn_graph when part is True
     """
-    global debug_fname
     filename = os.path.join(LAB_GRAPHFILE_PATH, LAB_CONNECTION_GRAPH_FILE)
     with open(filename) as fd:
         file_list = yaml.safe_load(fd)
 
     # Finding the graph file contains all duts from hostnames,
     for fn in file_list:
-        print_debug_msg(debug_fname, "Looking at conn graph file: %s for hosts %s" % (fn, hostnames))
+        logging.debug("Looking at conn graph file: %s for hosts %s" % (fn, hostnames))
         filename = os.path.join(LAB_GRAPHFILE_PATH, fn)
         lab_graph = Parse_Lab_Graph(filename)
         lab_graph.parse_graph()
-        print_debug_msg(debug_fname, "For file %s, got hostnames %s" % (fn, lab_graph.devices))
+        logging.debug("For file %s, got hostnames %s" % (fn, lab_graph.devices))
         if lab_graph.contains_hosts(hostnames, part):
-            print_debug_msg(debug_fname, ("Returning lab graph from conn graph file: %s for hosts %s" % (fn, hostnames)))
+            logging.debug("Returning lab graph from conn graph file: %s for hosts %s" % (fn, hostnames))
             return lab_graph
     # Fallback to return an empty connection graph, this is
     # needed to bridge the kvm test needs. The KVM test needs
@@ -489,7 +490,7 @@ def build_results(lab_graph, hostnames, ignore_error=False):
                 device_vlan_map_list[hostname] = {}
 
                 port_name_list_sorted = get_port_name_list(dev['HwSku'])
-                print_debug_msg(debug_fname, "For %s with hwsku %s, port_name_list is %s" % (hostname, dev['HwSku'], port_name_list_sorted))
+                logging.debug("For %s with hwsku %s, port_name_list is %s" % (hostname, dev['HwSku'], port_name_list_sorted))
                 for a_host_vlan in host_vlan["VlanList"]:
                     # Get the corresponding port for this vlan from the port vlan list for this hostname
                     found_port_for_vlan = False
@@ -529,9 +530,6 @@ def main():
         supports_check_mode=True
     )
     m_args = module.params
-    global debug_fname
-    debug_fname = create_debug_file("/tmp/conn_graph_debug.txt")
-
     anchor = m_args['anchor']
     if m_args['hosts']:
         hostnames = m_args['hosts']

ansible/module_utils/debug_utils.py

@@ -1,25 +1,53 @@
 import os
-from pprint import pprint
+import re
+import logging
 from ansible.module_utils.basic import datetime
 
+MAX_LOG_FILES_PER_MODULE = 10
 
-def create_debug_file(debug_fname, add_timestamp=True):
+
+def config_module_logging(module_name, log_path='/tmp', log_level=logging.DEBUG):
+    """Tool for configure logging to file for customized ansible modules
+
+    This tool aims to easy the effort for logging in customized ansible modules. To use it in customized ansible
+    module, please follow below pattern.
+    ```
+        from asible.module_utils.debug_utils import config_module_logging
+
+        config_module_logging('your_module_name')
+
+        logging.debug('some message')
+        logging.info('some message')
+    ```
+
+    After the function is imported and called with ansible module name as argument, then we can simply call
+    logging.debug, logging.info, etc., to log a message. The messages are automatically logged to files like:
+        /tmp/<ansible_module_name>_<iso_format_timestamp>.log
+
+    The default log path '/tmp' can be changed by passing argument `log_path` when calling this function.
+
+    Another important feature is that this function will also try to remove old log files of this module. The number
+    of most recent log files will be kept is specified by the global constant `MAX_LOG_FILES_PER_MODULE`.
+
+    Args:
+        module_name (str): Name of the customized ansible module.
+        log_path (str, optional): Path of log file. Defaults to '/tmp'.
+        log_level (log level, optional): Log level. Defaults to logging.DEBUG.
+    """
+
+    # Cleanup old log files to rotate
+    pattern = re.compile('{}_[\d\-T:\.]+\.log'.format(module_name))
+    existing_log_files = sorted([f for f in os.listdir(log_path) if pattern.match(f)])
+    old_log_files = existing_log_files[:-(MAX_LOG_FILES_PER_MODULE-1)]
+    try:
+        [os.remove(os.path.join(log_path, f)) for f in old_log_files]
+    except Exception as e:
+        pass
+
+    # Configure logging to file
     curtime = datetime.datetime.now().isoformat()
-    if add_timestamp:
-        # Check if there is an extension
-        fname_split = os.path.splitext(debug_fname)
-        if fname_split[1] != '':
-            # We have an extension
-            timed_debug_fname = (fname_split[0] + ".%s" + fname_split[1]) % curtime
-        else:
-            timed_debug_fname = (fname_split[0] + ".%s") % curtime
-    else:
-        timed_debug_fname = debug_fname
-    if os.path.exists(timed_debug_fname) and os.path.isfile(timed_debug_fname):
-        os.remove(timed_debug_fname)
-    return timed_debug_fname
-
-
-def print_debug_msg(debug_fname, msg):
-    with open(debug_fname, 'a') as fp:
-        pprint(msg, fp)
+    log_filename = os.path.join(log_path, '{}_{}.log'.format(module_name, curtime))
+    logging.basicConfig(
+        filename=log_filename,
+        format='%(asctime)s %(levelname)s #%(lineno)d: %(message)s',
+        level=log_level)