[Kimchi-devel] [PATCH v2] [Wok] Use callback instead of log file for run_command output

[Lucio Correia]

 * Ignore empty messages
 * Simplify exception message

Signed-off-by: Lucio Correia <luciojhc at linux.vnet.ibm.com>
---
 src/wok/asynctask.py | 13 +++++--------
 src/wok/utils.py     | 42 +++++++++++++-----------------------------
 2 files changed, 18 insertions(+), 37 deletions(-)

Changes in V2:
 * removed unnecessary line


diff --git a/src/wok/asynctask.py b/src/wok/asynctask.py
index ec3fbc1..fb614a2 100644
--- a/src/wok/asynctask.py
+++ b/src/wok/asynctask.py
@@ -46,15 +46,12 @@ class AsyncTask(object):
         self.thread.start()
 
     def _status_cb(self, message, success=None):
-        if success is None:
-            self.message = message
-            self._save_helper()
-            return
-
         if success is not None:
             self.status = 'finished' if success else 'failed'
-        self.message = message
-        self._save_helper()
+
+        if message.strip():
+            self.message = message
+            self._save_helper()
 
     def _save_helper(self):
         obj = {}
@@ -73,4 +70,4 @@ class AsyncTask(object):
         except Exception, e:
             cherrypy.log.error_log.error("Error in async_task %s " % self.id)
             cherrypy.log.error_log.error(traceback.format_exc())
-            cb("Unexpected exception: %s" % e.message, False)
+            cb(e.message, False)
diff --git a/src/wok/utils.py b/src/wok/utils.py
index 4b3b0ac..c78a77a 100644
--- a/src/wok/utils.py
+++ b/src/wok/utils.py
@@ -175,16 +175,21 @@ def import_module(module_name, class_name=''):
     return __import__(module_name, globals(), locals(), [class_name])
 
 
-def run_command(cmd, timeout=None, silent=False, tee=None,
-                env_vars=None):
+def run_command(cmd, timeout=None, silent=False, out_cb=None, env_vars=None):
     """
     cmd is a sequence of command arguments.
     timeout is a float number in seconds.
     timeout default value is None, means command run without timeout.
     silent is bool, it will log errors using debug handler not error.
     silent default value is False.
-    tee is a file path to store the output of the command, like 'tee' command.
-    tee default value is None, means output will not be logged.
+    out_cb is a callback that receives the whole command output every time a
+    new line is thrown by command. Default value is None, meaning that whole
+    output will be returned at the end of execution.
+
+    Returns a tuple (out, error, returncode) where:
+    out is the output thrown by command
+    error is an error message if applicable
+    returncode is an integer equal to the result of command execution
     """
     # subprocess.kill() can leave descendants running
     # and halting the execution. Using psutil to
@@ -202,24 +207,6 @@ def run_command(cmd, timeout=None, silent=False, tee=None,
         else:
             timeout_flag[0] = True
 
-    # function to append the given msg into the log_file
-    def tee_log(msg=None, log_file=None):
-        if (msg is None) or (log_file is None):
-            return
-
-        try:
-            f = open(log_file, 'a')
-        except IOError as e:
-            msg = "Failed to open file %s: " % log_file
-            wok_log.error("%s %s", msg, e)
-            return
-        msg += '\n'
-        try:
-            f.write(msg)
-        except TypeError:
-            f.write(msg.encode('utf_8'))
-        f.close()
-
     proc = None
     timer = None
     timeout_flag = [False]
@@ -239,9 +226,7 @@ def run_command(cmd, timeout=None, silent=False, tee=None,
             timer.start()
 
         wok_log.debug("Run command: '%s'", " ".join(cmd))
-        if tee is not None:
-            if os.path.exists(tee):
-                os.remove(tee)
+        if out_cb is not None:
             output = []
             while True:
                 line = ""
@@ -259,8 +244,7 @@ def run_command(cmd, timeout=None, silent=False, tee=None,
                 output.append(line)
                 if not line:
                     break
-                line = line.rstrip('\n\r')
-                tee_log(line, tee)
+                out_cb(''.join(output))
             out = ''.join(output)
             error = proc.stderr.read()
             returncode = proc.poll()
@@ -281,8 +265,8 @@ def run_command(cmd, timeout=None, silent=False, tee=None,
 
             else:
                 wok_log.error(msg)
-                if tee is not None:
-                    tee_log(msg, tee)
+                if out_cb is not None:
+                    out_cb(msg)
         elif error:
             wok_log.debug("error: %s returned from cmd: %s",
                           decode_value(error), decode_value(' '.join(cmd)))
-- 
1.9.1