Merge pull request #34 from yorch/run-every

Add debug mode and run every X seconds feature

README.md

@@ -32,14 +32,40 @@ Example Usage:
 --------------
 The PHP script has been designed to be called as a command line tool. Config is passed into it in the form of CLI parameters, for example:
 
-    php updater.php accessToken domain record recordtype
+    php updater.php accessToken domain record recordType
 
-    python updater.py accessToken domain record recordtype
+    python updater.py accessToken domain record recordType
 
 where 'accessToken' is your ['Personal Access Token'](https://cloud.digitalocean.com/settings/applications), 'domain' is the domain name you want to update
 (e.g: joebloggs.com), 'record' is the value of the record you want to update (e.g: home), and 'recordtype' is either A or AAAA.
 
 
+Run Continuously / Cron Style:
+-----------------------------
+
+You can run this script continuously (every X number of seconds) by calling it:
+
+    # If you wan to run it every 5 minutes
+    python updater.py accessToken domain record recordType --run-every 300
+
+This mode is perfect if you want to run inside a Docker container, where there is no cron by default.
+
+    TOKEN={your token}
+    DOMAIN={your domain}
+    RECORD={your record}
+    RTYPE=A
+    TIMEOUT=60
+    ARGS="$TOKEN $DOMAIN $RECORD $RTYPE --run-every $TIMEOUT"
+
+    docker run \
+      -it \
+      --rm \
+      --name do-ddns-updater \
+      -v "$PWD":/usr/src/app \
+      -w /usr/src/app \
+      python:3 python updater.py $ARGS
+
+
 Thanks to:
 ----------
 @surfer190, @nickwest, @gnoeley, @ryanwcraig, @c17r for adding additional features, testing code and feedback.

updater.py

@@ -66,12 +66,13 @@ def get_external_ip(expected_rtype):
     external_ip = get_url(CHECKIP_URL).rstrip()
     ip = ipaddress.ip_address(external_ip)
     if (ip.version == 4 and expected_rtype != 'A') or (ip.version == 6 and expected_rtype != 'AAAA'):
-        raise Exception('Expected Rtype {} but got {}'.format(expected_rtype, external_ip))
+        raise Exception("Expected Rtype {} but got {}".format(expected_rtype, external_ip))
+    debug("Obtaining the current external IP address: {}", external_ip)
     return external_ip
 
 
 def get_domain(name, token):
-    output('Fetching Domain ID for: {}', name)
+    debug("Fetching Domain ID for: {}", name)
     url = "%s/domains" % (APIURL)
 
     while True:
@@ -89,11 +90,11 @@ def get_domain(name, token):
         else:
             break
 
-    raise Exception("Could not find domain: %s" % name)
+    raise Exception(f"Could not find domain: {name}")
 
 
 def get_record(domain, name, rtype, token):
-    output("Fetching Record ID for: {}", name)
+    debug("Fetching Record ID for: {}", name)
     url = "%s/domains/%s/records" % (APIURL, domain['name'])
 
     while True:
@@ -111,61 +112,89 @@ def get_record(domain, name, rtype, token):
         else:
             break
 
-    raise Exception("Could not find record: %s" % name)
+    raise Exception(f"Could not find record: {name}")
 
 
 def set_record_ip(domain, record, ipaddr, token):
-    print("Updating record {}.{} to {}".format(record['name'], domain['name'], ipaddr))
+    debug("Updating record {}.{} to {}", record['name'], domain['name'], ipaddr)
 
     url = "%s/domains/%s/records/%s" % (APIURL, domain['name'], record['id'])
     data = json.dumps({'data': ipaddr}).encode('utf-8')
     headers = create_headers(token, {'Content-Type': 'application/json'})
 
     result = json.loads(put_url(url, data, headers))
     if result['domain_record']['data'] == ipaddr:
-        print("Success")
+        debug("Record {}.{} sucessfully updated to {}", record['name'], domain['name'], ipaddr)
+    else:
+        raise Exception(f"Could not set {record['name']}.{domain['name']} to {ipaddr}")
 
 
 def output(line, *args):
-    check = getattr(output, 'suppress', False)
-    if check:
+    quiet = getattr(output, 'quiet', False)
+    if quiet:
         return
-    print(line.format(*args))
+    print(f"[{datetime.now()}]", line.format(*args))
+
 
+def debug(line, *args):
+    debugEnable = getattr(debug, 'debug', False)
+    if not debugEnable:
+        return
+    output(f"DEBUG - {line}", *args)
 
 def process_args():
-    parser = argparse.ArgumentParser()
+    parser = argparse.ArgumentParser(description='Updates DNS records in Digital Ocean')
     parser.add_argument("token")
     parser.add_argument("domain")
     parser.add_argument("record")
     parser.add_argument("rtype", choices=['A', 'AAAA'])
-    parser.add_argument("-q", "--quiet", action="store_true", help='Only display output on IP change')
-    parser.add_argument("-ecoc", "--error-code-on-change", action="store_true", help='return Error Code 1 on IP change')
+    parser.add_argument("-q", "--quiet",
+                        action="store_true",
+                        help="Only display output on IP change")
+    parser.add_argument("-d", "--debug",
+                        action="store_true",
+                        help="Shows debug messages")
+    parser.add_argument("-ecoc", "--error-code-on-change",
+                        action="store_true",
+                        help="Return Error Code 1 on IP change")
+    parser.add_argument("-re", "--run-every",
+                        help="Run every number of seconds")
     return parser.parse_args()
 
 
-def run():
+def run(args):
     try:
-        args = process_args()
-        if args.quiet:
-            output.suppress = True
-
-        output("Update {}.{}: {}", args.record, args.domain, datetime.now())
+        debug("Update {}.{} record type {}", args.record, args.domain, args.rtype)
         ipaddr = get_external_ip(args.rtype)
         domain = get_domain(args.domain, args.token)
         record = get_record(domain, args.record, args.rtype, args.token)
         if record['data'] == ipaddr:
-            output("Records {}.{} already set to {}.", record['name'], domain['name'], ipaddr)
+            output("Record {}.{} already set to {}", record['name'], domain['name'], ipaddr)
             return 0
 
         set_record_ip(domain, record, ipaddr, args.token)
         ec = 1 if args.error_code_on_change else 0
         return ec
 
     except (Exception) as err:
-        print("Error: ", err, file=sys.stderr)
+        print(f"[{datetime.now()}] ERROR - {err}", file=sys.stderr)
         return -1
 
 
 if __name__ == '__main__':
-    sys.exit(run())
+    args = process_args()
+    if args.debug:
+        debug.debug = True
+
+    if args.quiet:
+        output.quiet = True
+
+    if args.run_every:
+        timeout = int(args.run_every)
+        output("Running this script continuously every {} seconds", timeout)
+        starttime=time.time()
+        while True:
+          run(args)
+          time.sleep(timeout - ((time.time() - starttime) % timeout))
+    else:
+        sys.exit(run(args))