diff options
Diffstat (limited to 'cloudinit/util.py')
| -rw-r--r-- | cloudinit/util.py | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/cloudinit/util.py b/cloudinit/util.py index aca82878..fc777b82 100644 --- a/cloudinit/util.py +++ b/cloudinit/util.py @@ -34,6 +34,7 @@ import sys import time from base64 import b64decode, b64encode from collections import deque, namedtuple +from contextlib import suppress from errno import EACCES, ENOENT from functools import lru_cache, total_ordering from pathlib import Path @@ -44,6 +45,7 @@ from cloudinit import features, importer from cloudinit import log as logging from cloudinit import ( mergers, + net, safeyaml, subp, temp_utils, @@ -1233,8 +1235,8 @@ def get_fqdn_from_hosts(hostname, filename="/etc/hosts"): return fqdn -def is_resolvable(name): - """determine if a url is resolvable, return a boolean +def is_resolvable(url) -> bool: + """determine if a url's network address is resolvable, return a boolean This also attempts to be resilent against dns redirection. Note, that normal nsswitch resolution is used here. So in order @@ -1246,6 +1248,8 @@ def is_resolvable(name): be resolved inside the search list. """ global _DNS_REDIRECT_IP + parsed_url = parse.urlparse(url) + name = parsed_url.hostname if _DNS_REDIRECT_IP is None: badips = set() badnames = ( @@ -1253,7 +1257,7 @@ def is_resolvable(name): "example.invalid.", "__cloud_init_expected_not_found__", ) - badresults = {} + badresults: dict = {} for iname in badnames: try: result = socket.getaddrinfo( @@ -1270,12 +1274,14 @@ def is_resolvable(name): LOG.debug("detected dns redirection: %s", badresults) try: + # ip addresses need no resolution + with suppress(ValueError): + if net.is_ip_address(parsed_url.netloc.strip("[]")): + return True result = socket.getaddrinfo(name, None) # check first result's sockaddr field addr = result[0][4][0] - if addr in _DNS_REDIRECT_IP: - return False - return True + return addr not in _DNS_REDIRECT_IP except (socket.gaierror, socket.error): return False @@ -1298,7 +1304,7 @@ def is_resolvable_url(url): logfunc=LOG.debug, msg="Resolving URL: " + url, func=is_resolvable, - args=(parse.urlparse(url).hostname,), + args=(url,), ) |