Fix typos, unused code, and error handling in storage operations

.gitignore

@@ -2,7 +2,7 @@
 ip-trigger-storage
 
 venv/
-__pychache__/
+__pycache__/
 
 *.pyc
 

README.md

@@ -11,7 +11,7 @@ Docker, docker-compose.
 
 # Setup
 
-Clone the repo `git clone git@github.com:vekerdyb/ip-trigger.py`
+Clone the repo `git clone git@github.com:vekerdyb/ip-trigger.git`
 
 Rename `config.py.tmp` to `config.py` and change the values. Uncomment any backend you want to use.
 

cloudflare_backend.py

@@ -6,8 +6,6 @@
 
 logger = logging.getLogger(__name__)
 
-URL = 'https://api.cloudflare.com/client/v4/'
-
 
 def on_ip_change(new_ip, log_handler=logger):
     log_handler.debug('Attempting to update Cloudflare IP for host {} to {}'.format(

ip-trigger.py

@@ -48,18 +48,24 @@ def curl_get(url, interface=None):
 
 def store_ip(ip):
     logger.debug('Attempting to open "{}" for appending'.format(STORAGE_FILE))
-    file = open(STORAGE_FILE, "a")
-    file.write(ip + "\n")
-    file.close()
+    with open(STORAGE_FILE, "a") as file:
+        file.write(ip + "\n")
     logger.debug("IP {} stored in file".format(ip))
 
 
 def retrieve_last_ip_from_storage():
     logger.debug('Attempting to retrieve last IP from "{}"'.format(STORAGE_FILE))
-    last_ip = subprocess.check_output(["tail", "-1", STORAGE_FILE])
-    last_ip = last_ip.strip().decode("utf-8")
-    logger.debug('Last IP: "{}"'.format(last_ip))
-    return last_ip
+    try:
+        last_ip = subprocess.check_output(["tail", "-1", STORAGE_FILE])
+        last_ip = last_ip.strip().decode("utf-8")
+        if not last_ip:
+            logger.debug("Storage file is empty")
+            return ""
+        logger.debug('Last IP: "{}"'.format(last_ip))
+        return last_ip
+    except subprocess.CalledProcessError:
+        logger.debug("Storage file does not exist or cannot be accessed")
+        return ""
 
 
 def detect_current_ip():

railgun_backend.py

@@ -22,7 +22,7 @@ def _send_simple_message(from_name, to, subject, text):
 
 def on_ip_change(new_ip, log_handler=logger):
     log_handler.debug(
-        'Sending email to "{}", becuase IP changed to "{}"'.format(config.RAILGUN['EMAIL_RECIPIENT'], new_ip))
+        'Sending email to "{}", because IP changed to "{}"'.format(config.RAILGUN['EMAIL_RECIPIENT'], new_ip))
 
     response = _send_simple_message(
         from_name=config.RAILGUN['FROM_NAME'],