Don't contact ip6.yunohost if we can know right away that there's no IPv6 at all on the system

data/hooks/diagnosis/10-ip.py

@@ -106,7 +106,7 @@ class IPDiagnoser(Diagnoser):
 
         # If we are indeed connected in ipv4 or ipv6, we should find a default route
         routes = check_output("ip -%s route" % protocol).split("\n")
-        if not [r for r in routes if r.startswith("default")]:
+        if not any(r.startswith("default") for r in routes):
             return False
 
         # We use the resolver file as a list of well-known, trustable (ie not google ;)) IPs that we can ping

src/yunohost/utils/network.py

@@ -18,10 +18,12 @@
     along with this program; if not, see http://www.gnu.org/licenses
 
 """
-import logging
+import os
 import re
-import subprocess
+import logging
+
 from moulinette.utils.network import download_text
+from moulinette.utils.process import check_output
 
 logger = logging.getLogger('yunohost.utils.network')
 
@@ -36,6 +38,17 @@ def get_public_ip(protocol=4):
     else:
         raise ValueError("invalid protocol version")
 
+    # We can know that ipv6 is not available directly if this file does not exists
+    if protocol == 6 and not os.path.exists("/proc/net/if_inet6"):
+        logger.debug("IPv6 appears not at all available on the system, so assuming there's no IP address for that version")
+        return None
+
+    # If we are indeed connected in ipv4 or ipv6, we should find a default route
+    routes = check_output("ip -%s route" % protocol).split("\n")
+    if not any(r.startswith("default") for r in routes):
+        logger.debug("No default route for IPv%s, so assuming there's no IP address for that version" % protocol)
+        return None
+
     try:
         return download_text(url, timeout=30).strip()
     except Exception as e:
@@ -47,7 +60,7 @@ def get_network_interfaces():
 
     # Get network devices and their addresses (raw infos from 'ip addr')
     devices_raw = {}
-    output = subprocess.check_output('ip addr show'.split())
+    output = check_output('ip addr show')
     for d in re.split(r'^(?:[0-9]+: )', output, flags=re.MULTILINE):
         # Extract device name (1) and its addresses (2)
         m = re.match(r'([^\s@]+)(?:@[\S]+)?: (.*)', d, flags=re.DOTALL)
@@ -62,7 +75,7 @@ def get_network_interfaces():
 
 def get_gateway():
 
-    output = subprocess.check_output('ip route show'.split())
+    output = check_output('ip route show')
     m = re.search(r'default via (.*) dev ([a-z]+[0-9]?)', output)
     if not m:
         return None