modernize porkbun-ddns

Modernizes the Python DDNS client:

* Use argparse for CLI argument handling (better help text, validation and error messages)
* Accept config file from stdin
* Use modern Python naming conventions
* Use ipaddress for validation
* Default value for the base url of the API
* Closes porkbundomains#2 
* Closes porkbundomains#3

porkbun-ddns.py

@@ -1,53 +1,94 @@
-import json
+#!/usr/bin/env python
+"""Porkbun Dynamic DNS client, Python Edition.
+
+Examples:
+    python porkbun-ddns.py /path/to/config.json example.com
+    python porkbun-ddns.py /path/to/config.json example.com www
+    python porkbun-ddns.py /path/to/config.json example.com '*'
+    python porkbun-ddns.py /path/to/config.json example.com -i 10.0.0.1
+"""
+
+import argparse, json, re, sys, ipaddress
 import requests
-import re
-import sys
-
-def getRecords(domain): #grab all the records so we know which ones to delete to make room for our record. Also checks to make sure we've got the right domain
-	allRecords=json.loads(requests.post(apiConfig["endpoint"] + '/dns/retrieve/' + domain, data = json.dumps(apiConfig)).text)
-	if allRecords["status"]=="ERROR":
-		print('Error getting domain. Check to make sure you specified the correct domain, and that API access has been switched on for this domain.');
-		sys.exit();
-	return(allRecords)
-
-def getMyIP():
-	ping = json.loads(requests.post(apiConfig["endpoint"] + '/ping/', data = json.dumps(apiConfig)).text)
-	return(ping["yourIp"])
-
-def deleteRecord():
-	for i in getRecords(rootDomain)["records"]:
-		if i["name"]==fqdn and (i["type"] == 'A' or i["type"] == 'ALIAS' or i["type"] == 'CNAME'):
-			print("Deleting existing " + i["type"] + " Record")
-			deleteRecord = json.loads(requests.post(apiConfig["endpoint"] + '/dns/delete/' + rootDomain + '/' + i["id"], data = json.dumps(apiConfig)).text)
-
-def createRecord():
-	createObj=apiConfig.copy()
-	createObj.update({'name': subDomain, 'type': 'A', 'content': myIP, 'ttl': 300})
-	endpoint = apiConfig["endpoint"] + '/dns/create/' + rootDomain
-	print("Creating record: " + fqdn + " with answer of " + myIP)
-	create = json.loads(requests.post(apiConfig["endpoint"] + '/dns/create/'+ rootDomain, data = json.dumps(createObj)).text)
-	return(create)
-
-if len(sys.argv)>2: #at least the config and root domain is specified
-	apiConfig = json.load(open(sys.argv[1])) #load the config file into a variable
-	rootDomain=sys.argv[2]	
-
-	if len(sys.argv)>3 and sys.argv[3]!='-i': #check if a subdomain was specified as the third argument
-		subDomain=sys.argv[3]
-		fqdn=subDomain + "." + rootDomain
-	else:
-		subDomain=''
-		fqdn=rootDomain
-
-	if len(sys.argv)>4 and sys.argv[3]=='-i': #check if IP is manually specified. There's probably a more-elegant way to do this
-		myIP=sys.argv[4]
-	elif len(sys.argv)>5 and sys.argv[4]=='-i':
-		myIP=sys.argv[5]
-	else:
-		myIP=getMyIP() #otherwise use the detected exterior IP address
-
-	deleteRecord()
-	print(createRecord()["status"])
-
-else:
-	print("Porkbun Dynamic DNS client, Python Edition\n\nError: not enough arguments. Examples:\npython porkbun-ddns.py /path/to/config.json example.com\npython porkbun-ddns.py /path/to/config.json example.com www\npython porkbun-ddns.py /path/to/config.json example.com '*'\npython porkbun-ddns.py /path/to/config.json example.com -i 10.0.0.1\n")
+
+
+def err(msg, *args, **kwargs):
+    msg = "Error: " + str(msg)
+    sys.stderr.write(msg.format(*args, **kwargs))
+    raise SystemExit(kwargs.get("code", 1))
+
+
+def api(args, target, data=None):
+    data = data or args.cfg
+    return json.loads(
+        requests.post(
+            args.cfg["endpoint"] + target, data=json.dumps(data)
+        ).text
+    )
+
+
+def get_records(args):
+    """grab all records, then find the correct one to replace."""
+    all_records = api(args, "/dns/retrieve/" + args.domain)
+    if all_records["status"] == "ERROR":
+        err(
+            "Failed to get records. "
+            "Make sure you specified the correct domain ({}), "
+            "and that API access has been enabled for this domain.",
+            args.domain,
+        )
+    return all_records
+
+
+def delete_record(args):
+    for i in get_records(args)["records"]:
+        if i["name"] == args.fqdn and i["type"] in ["A", "AAAA", "ALIAS", "CNAME"]:
+            print("Deleting existing {}-Record: {}".format(i["type"], i))
+            api(args, "/dns/delete/" + args.domain + "/" + i["id"])
+
+
+def create_record(args):
+    obj = args.cfg.copy()
+    type_ = "A" if args.public_ip.version == 4 else "AAAA"
+    obj.update({"name": args.subdomain, "type": type_, "content": args.public_ip.exploded, "ttl": 300})
+    print("Creating {}-Record for '{}' with answer of '{}'".format(type_, args.fqdn, args.public_ip))
+    return api(args, "/dns/create/" + args.domain, obj)
+
+
+def main(args):
+    parser = argparse.ArgumentParser(
+        description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter
+    )
+    parser.add_argument("config", nargs=1, help="path to config file")
+    parser.add_argument("domain", nargs=1, help="domain to be updated")
+    parser.add_argument("subdomain", nargs="?", default="", help="optional subdomain")
+    parser.add_argument(
+        "-i",
+        "--public-ip",
+        help="skip auto-detection and use this IP for entry",
+    )
+    args = parser.parse_args()
+
+    args.domain, args.config = args.domain[0], args.config[0]
+    args.fqdn = "{}.{}".format(args.subdomain, args.domain).strip(".")
+
+    try:
+        with sys.stdin if args.config == "-" else open(args.config) as file_:
+            args.cfg = json.load(file_)
+    except Exception as e:
+        err(e)
+    required = ["secretapikey", "apikey"]
+    if any(x not in args.cfg for x in required) or not isinstance(args.cfg, dict):
+        err("all of the following are required in '{}': {}", args.config, required)
+    args.cfg.setdefault("endpoint", "https://porkbun.com/api/json/v3/")
+
+    if not args.public_ip:
+        args.public_ip = api(args, "/ping/")["yourIp"]
+    args.public_ip = ipaddress.ip_address(args.public_ip)
+
+    delete_record(args)
+    print(create_record(args)["status"])
+
+
+if __name__ == "__main__":
+    main(sys.argv[1:])