From 475b0ff983f3eece51641bb49983295e54187599 Mon Sep 17 00:00:00 2001

From: Avra Sengupta <asengupt@redhat.com>

Date: Fri, 29 May 2015 18:11:01 +0530

Subject: [PATCH 06/18] snapshot/scheduler: Return proper error code in case of

 failure

    Backport of http://review.gluster.org/#/c/11005/

ENUM                              RETCODE     ERROR

----------------------------------------------------------

INTERNAL_ERROR                    2           Internal Error

SHARED_STORAGE_DIR_DOESNT_EXIST   3           Shared Storage Dir

                                              does not exist

SHARED_STORAGE_NOT_MOUNTED        4           Shared storage is not mounted

ANOTHER_TRANSACTION_IN_PROGRESS   5           Another transaction is in progress

INIT_FAILED                       6           Initialisation failed

SCHEDULING_ALREADY_DISABLED       7           Scheduler is already disabled

SCHEDULING_ALREADY_ENABLED        8           Scheduler is already enabled

NODE_NOT_INITIALISED              9           Node not initialised

ANOTHER_SCHEDULER_ACTIVE          10          Another scheduler is active

JOB_ALREADY_EXISTS                11          Job already exists

JOB_NOT_FOUND                     12          Job not found

INVALID_JOBNAME                   13          Jobname is invalid

INVALID_VOLNAME                   14          Volname is invalid

INVALID_SCHEDULE                  15          Schedule is invalid

INVALID_ARG                       16          Argument is invalid

Change-Id: Ia1da166659099f4c951fcdb4d755529e41167b80

BUG: 1223206

Signed-off-by: Avra Sengupta <asengupt@redhat.com>

Reviewed-on: https://code.engineering.redhat.com/gerrit/50090

Reviewed-by: Rajesh Joseph <rjoseph@redhat.com>

Tested-by: Rajesh Joseph <rjoseph@redhat.com>

---

 extras/snap_scheduler/snap_scheduler.py | 142 ++++++++++++++++++--------------

 1 file changed, 81 insertions(+), 61 deletions(-)

diff --git a/extras/snap_scheduler/snap_scheduler.py b/extras/snap_scheduler/snap_scheduler.py

index e7c1791..1c5f938 100755

--- a/extras/snap_scheduler/snap_scheduler.py

+++ b/extras/snap_scheduler/snap_scheduler.py

@@ -38,6 +38,21 @@ tasks = {}

 longest_field = 12

 current_scheduler = ""

+INTERNAL_ERROR = 2

+SHARED_STORAGE_DIR_DOESNT_EXIST = 3

+SHARED_STORAGE_NOT_MOUNTED = 4

+ANOTHER_TRANSACTION_IN_PROGRESS = 5

+INIT_FAILED = 6

+SCHEDULING_ALREADY_DISABLED = 7

+SCHEDULING_ALREADY_ENABLED = 8

+NODE_NOT_INITIALISED = 9

+ANOTHER_SCHEDULER_ACTIVE = 10

+JOB_ALREADY_EXISTS = 11

+JOB_NOT_FOUND = 12

+INVALID_JOBNAME = 13

+INVALID_VOLNAME = 14

+INVALID_SCHEDULE = 15

+INVALID_ARG = 16

 def output(msg):

     print("%s: %s" % (SCRIPT_NAME, msg))

@@ -66,7 +81,7 @@ def initLogger():

 def scheduler_status():

-    success = False

+    ret = INTERNAL_ERROR

     global scheduler_enabled

     try:

         f = os.path.realpath(GCRON_TASKS)

@@ -76,33 +91,32 @@ def scheduler_status():

         else:

             log.info("Snapshot scheduler is currently enabled.")

             scheduler_enabled = True

-        success = True

+        ret = 0

     except:

         log.error("Failed to enable snapshot scheduling. Error: "

                   "Failed to check the status of %s.", GCRON_DISABLED)

-    return success

+    return ret

 def enable_scheduler():

     ret = scheduler_status()

-    if ret:

+    if ret == 0:

         if not scheduler_enabled:

             # Check if another scheduler is active.

             ret = get_current_scheduler()

-            if ret:

+            if ret == 0:

                 if (current_scheduler != "none"):

                     print_str = "Failed to enable snapshot scheduling. " \

                                 "Error: Another scheduler is active."

                     log.error(print_str)

                     output(print_str)

-                    ret = False

+                    ret = ANOTHER_SCHEDULER_ACTIVE

                     return ret

             else:

                 print_str = "Failed to get current scheduler info."

                 log.error(print_str)

                 output(print_str)

-                ret = False

                 return ret

             log.info("Enabling snapshot scheduler.")

@@ -118,23 +132,24 @@ def enable_scheduler():

                 except IOError as (errno, strerror):

                     log.error("Failed to open %s. Error: %s.",

                               GCRON_ENABLED, strerror)

-                    ret = False

+                    ret = INTERNAL_ERROR

                     return ret

                 os.symlink(GCRON_ENABLED, GCRON_TASKS)

                 update_current_scheduler("cli")

                 log.info("Snapshot scheduling is enabled")

                 output("Snapshot scheduling is enabled")

+                ret = 0

             except IOError as (errno, strerror):

                 print_str = "Failed to enable snapshot scheduling. Error: "+strerror

                 log.error(print_str)

                 output(print_str)

-                ret = False

+                ret = INTERNAL_ERROR

         else:

             print_str = "Failed to enable snapshot scheduling. " \

                         "Error: Snapshot scheduling is already enabled."

             log.error(print_str)

             output(print_str)

-            ret = False

+            ret = SCHEDULING_ALREADY_ENABLED

     else:

         print_str = "Failed to enable snapshot scheduling. " \

                     "Error: Failed to check scheduler status."

@@ -146,14 +161,14 @@ def enable_scheduler():

 def disable_scheduler():

     ret = scheduler_status()

-    if ret:

+    if ret == 0:

         if scheduler_enabled:

             log.info("Disabling snapshot scheduler.")

             try:

                 # Check if another scheduler is active. If not, then

                 # update current scheduler to "none". Else do nothing.

                 ret = get_current_scheduler()

-                if ret:

+                if ret == 0:

                     if (current_scheduler == "cli"):

                         update_current_scheduler("none")

                 else:

@@ -161,7 +176,6 @@ def disable_scheduler():

                                 "Error: Failed to get current scheduler info."

                     log.error(print_str)

                     output(print_str)

-                    ret = False

                     return ret

                 if os.path.exists(GCRON_DISABLED):

@@ -173,22 +187,24 @@ def disable_scheduler():

                 os.symlink(GCRON_DISABLED, GCRON_TASKS)

                 log.info("Snapshot scheduling is disabled")

                 output("Snapshot scheduling is disabled")

+                ret = 0

             except IOError as (errno, strerror):

                 print_str = "Failed to disable snapshot scheduling. Error: "+strerror

                 log.error(print_str)

                 output(print_str)

-                ret = False

+                ret = INTERNAL_ERROR

         else:

             print_str = "Failed to disable scheduling. " \

                         "Error: Snapshot scheduling is already disabled."

             log.error(print_str)

             output(print_str)

-            ret = False

+            ret = SCHEDULING_ALREADY_DISABLED

     else:

         print_str = "Failed to disable snapshot scheduling. " \

                     "Error: Failed to check scheduler status."

         log.error(print_str)

         output(print_str)

+        ret = INTERNAL_ERROR

     return ret

@@ -211,10 +227,10 @@ def load_tasks_from_file():

                                     len(schedule))

                 tasks[jobname] = schedule+":"+volname

             f.close()

-        ret = True

+        ret = 0

     except IOError as (errno, strerror):

         log.error("Failed to open %s. Error: %s.", GCRON_ENABLED, strerror)

-        ret = False

+        ret = INTERNAL_ERROR

     return ret

@@ -225,10 +241,10 @@ def get_current_scheduler():

         with open(CURRENT_SCHEDULER, 'r') as f:

             current_scheduler = f.readline().rstrip('\n')

             f.close()

-        ret = True

+        ret = 0

     except IOError as (errno, strerror):

         log.error("Failed to open %s. Error: %s.", CURRENT_SCHEDULER, strerror)

-        ret = False

+        ret = INTERNAL_ERROR

     return ret

@@ -236,7 +252,7 @@ def get_current_scheduler():

 def list_schedules():

     log.info("Listing snapshot schedules.")

     ret = load_tasks_from_file()

-    if ret:

+    if ret == 0:

         if len(tasks) == 0:

             output("No snapshots scheduled")

         else:

@@ -255,6 +271,7 @@ def list_schedules():

                           longest_field + 5)

                 operation = "Snapshot Create".ljust(longest_field+5)

                 print(jobname+schedule+operation+volname)

+            ret = 0

     else:

         print_str = "Failed to list snapshot schedules. " \

                     "Error: Failed to load tasks from "+GCRON_ENABLED

@@ -265,7 +282,6 @@ def list_schedules():

 def write_tasks_to_file():

-    ret = False

     try:

         with open(TMP_FILE, "w", 0644) as f:

             # If tasks is empty, just create an empty tmp file

@@ -282,16 +298,15 @@ def write_tasks_to_file():

             f.close()

     except IOError as (errno, strerror):

         log.error("Failed to open %s. Error: %s.", TMP_FILE, strerror)

-        ret = False

+        ret = INTERNAL_ERROR

         return ret

     shutil.move(TMP_FILE, GCRON_ENABLED)

-    ret = True

+    ret = 0

     return ret

 def update_current_scheduler(data):

-    ret = False

     try:

         with open(TMP_FILE, "w", 0644) as f:

             f.write("%s" % data)

@@ -300,11 +315,11 @@ def update_current_scheduler(data):

             f.close()

     except IOError as (errno, strerror):

         log.error("Failed to open %s. Error: %s.", TMP_FILE, strerror)

-        ret = False

+        ret = INTERNAL_ERROR

         return ret

     shutil.move(TMP_FILE, CURRENT_SCHEDULER)

-    ret = True

+    ret = 0

     return ret

@@ -312,17 +327,17 @@ def update_current_scheduler(data):

 def add_schedules(jobname, schedule, volname):

     log.info("Adding snapshot schedules.")

     ret = load_tasks_from_file()

-    if ret:

+    if ret == 0:

         if jobname in tasks:

             print_str = ("%s already exists in schedule. Use "

                          "'edit' to modify %s" % (jobname, jobname))

             log.error(print_str)

             output(print_str)

-            ret = False

+            ret = JOB_ALREADY_EXISTS

         else:

             tasks[jobname] = schedule + ":" + volname

             ret = write_tasks_to_file()

-            if ret:

+            if ret == 0:

                 # Create a LOCK_FILE for the job

                 job_lockfile = LOCK_FILE_DIR + jobname

                 try:

@@ -331,10 +346,11 @@ def add_schedules(jobname, schedule, volname):

                 except IOError as (errno, strerror):

                     log.error("Failed to open %s. Error: %s.",

                               job_lockfile, strerror)

-                    ret = False

+                    ret = INTERNAL_ERROR

                     return ret

                 log.info("Successfully added snapshot schedule %s" % jobname)

                 output("Successfully added snapshot schedule")

+                ret = 0

     else:

         print_str = "Failed to add snapshot schedule. " \

                     "Error: Failed to load tasks from "+GCRON_ENABLED

@@ -347,11 +363,11 @@ def add_schedules(jobname, schedule, volname):

 def delete_schedules(jobname):

     log.info("Delete snapshot schedules.")

     ret = load_tasks_from_file()

-    if ret:

+    if ret == 0:

         if jobname in tasks:

             del tasks[jobname]

             ret = write_tasks_to_file()

-            if ret:

+            if ret == 0:

                 # Delete the LOCK_FILE for the job

                 job_lockfile = LOCK_FILE_DIR+jobname

                 try:

@@ -359,15 +375,18 @@ def delete_schedules(jobname):

                 except IOError as (errno, strerror):

                     log.error("Failed to open %s. Error: %s.",

                               job_lockfile, strerror)

+                    ret = INTERNAL_ERROR

+                    return ret

                 log.info("Successfully deleted snapshot schedule %s"

                          % jobname)

                 output("Successfully deleted snapshot schedule")

+                ret = 0

         else:

             print_str = ("Failed to delete %s. Error: No such "

                          "job scheduled" % jobname)

             log.error(print_str)

             output(print_str)

-            ret = False

+            ret = JOB_NOT_FOUND

     else:

         print_str = "Failed to delete snapshot schedule. " \

                     "Error: Failed to load tasks from "+GCRON_ENABLED

@@ -380,11 +399,11 @@ def delete_schedules(jobname):

 def edit_schedules(jobname, schedule, volname):

     log.info("Editing snapshot schedules.")

     ret = load_tasks_from_file()

-    if ret:

+    if ret == 0:

         if jobname in tasks:

             tasks[jobname] = schedule+":"+volname

             ret = write_tasks_to_file()

-            if ret:

+            if ret == 0:

                 log.info("Successfully edited snapshot schedule %s" % jobname)

                 output("Successfully edited snapshot schedule")

         else:

@@ -392,7 +411,7 @@ def edit_schedules(jobname, schedule, volname):

                          "job scheduled" % jobname)

             log.error(print_str)

             output(print_str)

-            ret = False

+            ret = JOB_NOT_FOUND

     else:

         print_str = "Failed to edit snapshot schedule. " \

                     "Error: Failed to load tasks from "+GCRON_ENABLED

@@ -413,7 +432,7 @@ def initialise_scheduler():

             f.close()

     except IOError as (errno, strerror):

         log.error("Failed to open /tmp/crontab. Error: %s.", strerror)

-        ret = False

+        ret = INIT_FAILED

         return ret

     shutil.move("/tmp/crontab", GCRON_UPDATE_TASK)

@@ -424,7 +443,7 @@ def initialise_scheduler():

             f.close()

         except IOError as (errno, strerror):

             log.error("Failed to open %s. Error: %s.", GCRON_TASKS, strerror)

-            ret = False

+            ret = INIT_FAILED

             return ret

     if os.path.lexists(GCRON_CROND_TASK):

@@ -435,22 +454,22 @@ def initialise_scheduler():

     log.info("Successfully inited snapshot scheduler for this node")

     output("Successfully inited snapshot scheduler for this node")

-    ret = True

+    ret = 0

     return ret

 def syntax_checker(args):

-    ret = False

-

     if hasattr(args, 'jobname'):

         if (len(args.jobname.split()) != 1):

             output("Invalid Jobname. Jobname should not be empty and should not contain \" \" character.")

+            ret = INVALID_JOBNAME

             return ret

         args.jobname=args.jobname.strip()

     if hasattr(args, 'volname'):

         if (len(args.volname.split()) != 1):

             output("Invalid Volname. Volname should not be empty and should not contain \" \" character.")

+            ret = INVALID_VOLNAME

             return ret

         args.volname=args.volname.strip()

@@ -464,26 +483,25 @@ def syntax_checker(args):

             print ("| | +-------- Day of the Month  (range: 1-31)")

             print ("| +---------- Hour              (range: 0-23)")

             print ("+------------ Minute            (range: 0-59)")

+            ret = INVALID_SCHEDULE

             return ret

-    ret = True

+    ret = 0

     return ret

 def perform_operation(args):

-    ret = False

-

     # Initialise snapshot scheduler on local node

     if args.action == "init":

         ret = initialise_scheduler()

-        if not ret:

+        if ret != 0:

             output("Failed to initialise snapshot scheduling")

         return ret

     # Disable snapshot scheduler

     if args.action == "disable_force":

         ret = disable_scheduler()

-        if ret:

+        if ret == 0:

             subprocess.Popen(["touch", "-h", GCRON_TASKS])

         return ret

@@ -495,12 +513,13 @@ def perform_operation(args):

                      "the snap scheduler for the local node.")

         log.error(print_str)

         output(print_str)

+        ret = NODE_NOT_INITIALISED

         return ret

     # Check status of snapshot scheduler.

     if args.action == "status":

         ret = scheduler_status()

-        if ret:

+        if ret == 0:

             if scheduler_enabled:

                 output("Snapshot scheduling status: Enabled")

             else:

@@ -512,14 +531,14 @@ def perform_operation(args):

     # Enable snapshot scheduler

     if args.action == "enable":

         ret = enable_scheduler()

-        if ret:

+        if ret == 0:

             subprocess.Popen(["touch", "-h", GCRON_TASKS])

         return ret

     # Disable snapshot scheduler

     if args.action == "disable":

         ret = disable_scheduler()

-        if ret:

+        if ret == 0:

             subprocess.Popen(["touch", "-h", GCRON_TASKS])

         return ret

@@ -531,33 +550,34 @@ def perform_operation(args):

     # Add snapshot schedules

     if args.action == "add":

         ret = syntax_checker(args)

-        if not ret:

+        if ret != 0:

             return ret

         ret = add_schedules(args.jobname, args.schedule, args.volname)

-        if ret:

+        if ret == 0:

             subprocess.Popen(["touch", "-h", GCRON_TASKS])

         return ret

     # Delete snapshot schedules

     if args.action == "delete":

         ret = syntax_checker(args)

-        if not ret:

+        if ret != 0:

             return ret

         ret = delete_schedules(args.jobname)

-        if ret:

+        if ret == 0:

             subprocess.Popen(["touch", "-h", GCRON_TASKS])

         return ret

     # Edit snapshot schedules

     if args.action == "edit":

         ret = syntax_checker(args)

-        if not ret:

+        if ret != 0:

             return ret

         ret = edit_schedules(args.jobname, args.schedule, args.volname)

-        if ret:

+        if ret == 0:

             subprocess.Popen(["touch", "-h", GCRON_TASKS])

         return ret

+    ret = INVALID_ARG

     return ret

@@ -601,11 +621,11 @@ def main():

     if not os.path.exists(SHARED_STORAGE_DIR):

         output("Failed: "+SHARED_STORAGE_DIR+" does not exist.")

-        return ret

+        return SHARED_STORAGE_DIR_DOESNT_EXIST

     if not os.path.ismount(SHARED_STORAGE_DIR):

         output("Failed: Shared storage is not mounted at "+SHARED_STORAGE_DIR)

-        return ret

+        return SHARED_STORAGE_NOT_MOUNTED

     if not os.path.exists(SHARED_STORAGE_DIR+"/snaps/"):

         try:

@@ -615,6 +635,7 @@ def main():

                 log.error("Failed to create %s : %s", SHARED_STORAGE_DIR+"/snaps/", strerror)

                 output("Failed to create %s. Error: %s"

                        % (SHARED_STORAGE_DIR+"/snaps/", strerror))

+                return INTERNAL_ERROR

     if not os.path.exists(GCRON_ENABLED):

         f = os.open(GCRON_ENABLED, os.O_CREAT | os.O_NONBLOCK, 0644)

@@ -628,6 +649,7 @@ def main():

                 log.error("Failed to create %s : %s", LOCK_FILE_DIR, strerror)

                 output("Failed to create %s. Error: %s"

                        % (LOCK_FILE_DIR, strerror))

+                return INTERNAL_ERROR

     if not os.path.exists(CURRENT_SCHEDULER):

         update_current_scheduler("none")

@@ -637,19 +659,17 @@ def main():

         try:

             fcntl.flock(f, fcntl.LOCK_EX | fcntl.LOCK_NB)

             ret = perform_operation(args)

-            if not ret:

-                ret = 1

-            else:

-                ret = 0

             fcntl.flock(f, fcntl.LOCK_UN)

         except IOError as (errno, strerror):

             log.info("%s is being processed by another agent.", LOCK_FILE)

             output("Another snap_scheduler command is running. "

                    "Please try again after some time.")

+            return ANOTHER_TRANSACTION_IN_PROGRESS

         os.close(f)

     except IOError as (errno, strerror):

         log.error("Failed to open %s : %s", LOCK_FILE, strerror)

         output("Failed to open %s. Error: %s" % (LOCK_FILE, strerror))

+        return INTERNAL_ERROR

     return ret

-- 

1.9.3