Add lockfile to prevent multiple instances of the script from running…

… simultaneously (#1)

.gitignore

@@ -7,3 +7,4 @@ __pycache__/
 smart-runner.conf
 smart-runner.json
 smart-runner.log
+.smart-runner.lock

README.md

@@ -17,10 +17,11 @@ S.M.A.R.T Runner is a Python script designed to automate the scheduling and exec
 - **Parallel Testing:** Specify how many disks to test simultaneously for both short and long tests.
 - **Offset Timing:** Configure waiting periods between tests to avoid overloading the system or testing too frequently.
 - **Logging:** Keep track of tests, results, and any errors in a specified log file.
-- **Email Notifications:** Receive email alerts for test failures or potential disk issues.
+- **Email Notifications:** Receive email alerts for test failures.
 - **Configurable SMTP:** Set up custom SMTP server settings for sending out email notifications.
 - **Easy Cron Integration:** Run the script as a daily cron job for hands-off operation.
 - **Intelligent Disk Detection:** Automatically detect and handle disks based on mount points if specified.
+- **Lock File:** Prevent multiple instances of the script from running simultaneously.
 
 ## Setup Requirements
 
@@ -39,7 +40,7 @@ The script is configured via a `smart-runner.conf` file. Here's an explanation o
 | Section    | Option           | Description                                                                                                                        |
 | ---------- | ---------------- | ---------------------------------------------------------------------------------------------------------------------------------- |
 | `disks`    | (list)           | List the devices or mounts to test. Devices are listed as `/dev/sdX`. If a mount is given the disk will automatically be resolved. |
-| `database` | `file`           | Path to the file where test schedules and results are stored.                                                                      |
+| `database` | `file`           | Path to the file where test dates are stored.                                                                                      |
 | `short`    | `enabled`        | Set to `true` to enable short SMART tests.                                                                                         |
 |            | `frequency_days` | How often (in days) to run a short test on each disk.                                                                              |
 |            | `disks_per_run`  | Number of disks to test in parallel for short tests. Set to 0 for all.                                                             |

smart-runner.py

@@ -8,6 +8,7 @@
     Database,
     Disk,
     Email,
+    Lock,
     Logger,
     Message,
     NotEnabledException,
@@ -20,7 +21,6 @@
     TooSoonException,
 )
 from sys import exit
-from traceback import print_exc
 
 
 def sendTestFailureEmail(config, logger, test, disk):
@@ -55,6 +55,7 @@ def sendTestFailureEmail(config, logger, test, disk):
 
 def main():
     try:
+        Lock()
         args = Args()
         config = Config(configFile=args.config)
         db = Database(dbFile=config.database.file)
@@ -175,7 +176,6 @@ def main():
 
     except Exception as e:
         print("Error: {}".format(e))
-        print_exc(e)
         exit(1)
 
 

smart_runner/__init__.py

@@ -4,5 +4,6 @@
 from .database import *
 from .disk import *
 from .email import *
+from .lock import *
 from .logger import *
 from .test import *

smart_runner/lock.py

@@ -0,0 +1,32 @@
+from atexit import register
+from os import getcwd, remove
+
+LOCK_FILE_PATH = getcwd() + "/.smart-runner.lock"
+
+
+class Lock:
+    def __init__(self):
+        if self.isLocked():
+            raise RuntimeError("smart-runner is already running")
+
+        self.createLock()
+
+        # Register the removeLock function to be called on exit
+        register(self.removeLock)
+
+    def createLock(self):
+        with open(LOCK_FILE_PATH, "w") as lockFile:
+            lockFile.write("")
+
+    def removeLock(self):
+        try:
+            remove(LOCK_FILE_PATH)
+        except FileNotFoundError:
+            pass  # If the file is already removed or doesn't exist, ignore the error
+
+    def isLocked(self):
+        try:
+            with open(LOCK_FILE_PATH, "r") as lockFile:
+                return True
+        except FileNotFoundError:
+            return False