Do not rely on Moulinette, integration with Yunohost of mDNS broadcast

bin/yunomdns

@@ -6,115 +6,278 @@ Pythonic declaration of mDNS .local domains for YunoHost
 Based off https://github.com/jstasiak/python-zeroconf/blob/master/tests/test_asyncio.py
 """
 
+import subprocess
 import os
+import re
 import sys
 import argparse
+import yaml
 
 import asyncio
 import logging
 import socket
 import time
-from typing import List
-
-sys.path.insert(0, "/usr/lib/moulinette/")
-from yunohost.domain import domain_list
-from yunohost.utils.network import get_network_interfaces
-from yunohost.settings import settings_get
-from moulinette import m18n
-from moulinette.interfaces.cli import get_locale
+from typing import List, Dict
 
+from zeroconf import DNSEntry, DNSRecord
 from zeroconf.asyncio import AsyncServiceInfo, AsyncZeroconf
 
+# Helper command taken from Moulinette
+def check_output(args, stderr=subprocess.STDOUT, shell=True, **kwargs):
+    """Run command with arguments and return its output as a byte string
+    Overwrite some of the arguments to capture standard error in the result
+    and use shell by default before calling subprocess.check_output.
+    """
+    return (
+        subprocess.check_output(args, stderr=stderr, shell=shell, **kwargs)
+        .decode("utf-8")
+        .strip()
+    )
 
-async def register_services(aiozc: AsyncZeroconf, infos: List[AsyncServiceInfo]) -> None:
-    tasks = [aiozc.async_register_service(info) for info in infos]
+# Helper command taken from Moulinette
+def _extract_inet(string, skip_netmask=False, skip_loopback=True):
+    """
+    Extract IP addresses (v4 and/or v6) from a string limited to one
+    address by protocol
+
+    Keyword argument:
+        string -- String to search in
+        skip_netmask -- True to skip subnet mask extraction
+        skip_loopback -- False to include addresses reserved for the
+            loopback interface
+
+    Returns:
+        A dict of {protocol: address} with protocol one of 'ipv4' or 'ipv6'
+
+    """
+    ip4_pattern = (
+        r"((25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}"
+    )
+    ip6_pattern = r"(((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)::((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)"
+    ip4_pattern += r"/[0-9]{1,2})" if not skip_netmask else ")"
+    ip6_pattern += r"/[0-9]{1,3})" if not skip_netmask else ")"
+    result = {}
+
+    for m in re.finditer(ip4_pattern, string):
+        addr = m.group(1)
+        if skip_loopback and addr.startswith("127."):
+            continue
+
+        # Limit to only one result
+        result["ipv4"] = addr
+        break
+
+    for m in re.finditer(ip6_pattern, string):
+        addr = m.group(1)
+        if skip_loopback and addr == "::1":
+            continue
+
+        # Limit to only one result
+        result["ipv6"] = addr
+        break
+
+    return result
+
+# Helper command taken from Moulinette
+def get_network_interfaces():
+    # Get network devices and their addresses (raw infos from 'ip addr')
+    devices_raw = {}
+    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)
+        if m:
+            devices_raw[m.group(1)] = m.group(2)
+
+    # Parse relevant informations for each of them
+    devices = {
+        name: _extract_inet(addrs)
+        for name, addrs in devices_raw.items()
+        if name != "lo"
+    }
+
+    return devices
+
+# async commands
+async def register_services(aiozcs: Dict[AsyncZeroconf, List[AsyncServiceInfo]]) -> None:
+    tasks = []
+    for aiozc, infos in aiozcs.items():
+        for info in infos:
+            tasks.append(aiozc.async_register_service(info))
     background_tasks = await asyncio.gather(*tasks)
     await asyncio.gather(*background_tasks)
 
-async def unregister_services(aiozc: AsyncZeroconf, infos: List[AsyncServiceInfo]) -> None:
-    tasks = [aiozc.async_unregister_service(info) for info in infos]
+async def unregister_services(aiozcs: Dict[AsyncZeroconf, List[AsyncServiceInfo]]) -> None:
+    for aiozc, infos in aiozcs.items():
+        for info in infos:
+            tasks.append(aiozc.async_unregister_service(info))
     background_tasks = await asyncio.gather(*tasks)
     await asyncio.gather(*background_tasks)
 
-async def close_aiozc(aiozc: AsyncZeroconf) -> None:
-    await aiozc.async_close()
+async def close_aiozcs(aiozcs: Dict[AsyncZeroconf, List[AsyncServiceInfo]]) -> None:
+    tasks = []
+    for aiozc in aiozcs:
+        tasks.append(aiozc.async_close())
+    background_tasks = await asyncio.gather(*tasks)
+    await asyncio.gather(*background_tasks)
 
 
 if __name__ == '__main__':
     logging.basicConfig(level=logging.DEBUG)
 
-    parser = argparse.ArgumentParser()
+
+    ###
+    #  ARGUMENTS
+    ###
+
+    parser = argparse.ArgumentParser(description='''
+                                                 mDNS broadcast for .local domains.
+                                                 Configuration file: /etc/yunohost/mdns.yml
+                                                 Subdomains are not supported.
+                                                 ''')
     parser.add_argument('--debug', action='store_true')
+    parser.add_argument('--regen', nargs='?', const='as_stored', choices=['domains', 'interfaces', 'all', 'as_stored'],
+                        help='''
+                             Regenerates selection into the configuration file then starts mDNS broadcasting.
+                             ''')
+    parser.add_argument('--set-regen', choices=['domains', 'interfaces', 'all', 'none'],
+                      help='''
+                           Set which part of the configuration to be regenerated.
+                           Implies --regen as_stored, with newly stored parameter.
+                           ''')
+    able = parser.add_mutually_exclusive_group()
+    able.add_argument('--enable', action='store_true', help='Enables mDNS broadcast, and regenerates the configuration')
+    able.add_argument('--disable', action='store_true')
     args = parser.parse_args()
 
     if args.debug:
         logging.getLogger('zeroconf').setLevel(logging.DEBUG)
-
-
-    local_domains = [ d for d in domain_list()['domains'] if d.endswith('.local') ]
-
-    m18n.load_namespace("yunohost")
-    m18n.set_locale(get_locale())
-
-    if settings_get('mdns.interfaces'):
-        wanted_interfaces = settings_get('mdns.interfaces').split()
+        logging.getLogger('asyncio').setLevel(logging.DEBUG)
     else:
-        wanted_interfaces = []
-        print('No interface listed for broadcast.')
+        logging.getLogger('zeroconf').setLevel(logging.WARNING)
+        logging.getLogger('asyncio').setLevel(logging.WARNING)
 
-    aiozcs = []
+    ###
+    #  CONFIG
+    ###
+
+    with open('/etc/yunohost/mdns.yml', 'r') as f:
+        config = yaml.load(f) or {}
+    updated = False
+
+    if args.enable:
+        config['enabled'] = True
+        args.regen = 'as_stored'
+        updated = True
+
+    if args.disable:
+        config['enabled'] = False
+        updated = True
+
+    if args.set_regen:
+        config['regen'] = args.set_regen
+        args.regen = 'as_stored'
+        updated = True
+
+    if args.regen:
+        if args.regen == 'as_stored':
+            r = config['regen']
+        else:
+            r = args.regen
+        if r == 'none':
+            print('Regeneration disabled.')
+        if r == 'interfaces' or r == 'all':
+            config['interfaces'] = [ i for i in get_network_interfaces() ]
+            print('Regenerated interfaces list: ' + str(config['interfaces']))
+        if r == 'domains' or r == 'all':
+            import glob
+            config['domains'] = [ d.rsplit('/',1)[1][:-2] for d in glob.glob('/etc/nginx/conf.d/*.local.d') ]
+            print('Regenerated domains list: ' + str(config['domains']))
+        updated = True
+
+    if updated:
+        with open('/etc/yunohost/mdns.yml', 'w') as f:
+            yaml.safe_dump(config, f, default_flow_style=False)
+            print('Configuration file updated.')
+
+    ###
+    #  MAIN SCRIPT
+    ###
+
+    if config['enabled'] is not True:
+        print('YunomDNS is disabled.')
+        sys.exit(0)
+
+    if config['interfaces'] is None:
+        print('No interface listed for broadcast.')
+        sys.exit(0)
+
+    aiozcs = {}
+    tasks = []
+    loop = asyncio.get_event_loop()
     interfaces = get_network_interfaces()
-    for interface in wanted_interfaces:
-        infos = []
+    for interface in config['interfaces']:
+        infos = [] # List of ServiceInfo objects, to feed Zeroconf
         ips = [] # Human-readable IPs
         b_ips = [] # Binary-convered IPs
 
         # Parse the IPs and prepare their binary version
+        addressed = False
         try:
             ip = interfaces[interface]['ipv4'].split('/')[0]
+            if len(ip)>0: addressed = True
             ips.append(ip)
             b_ips.append(socket.inet_pton(socket.AF_INET, ip))
         except:
             pass
         try:
             ip = interfaces[interface]['ipv6'].split('/')[0]
+            if len(ip)>0: addressed = True
             ips.append(ip)
             b_ips.append(socket.inet_pton(socket.AF_INET6, ip))
         except:
             pass
 
+        # If at least one IP is listed
+        if addressed:
             # Create a ServiceInfo object for each .local domain
-        for d in local_domains:
+            for d in config['domains']:
                 d_domain=d.replace('.local','')
                 infos.append(
                     AsyncServiceInfo(
-                    type_="_device-info._tcp.local.",
-                    name=d_domain+f"._device-info._tcp.local.",
+                        type_='_device-info._tcp.local.',
+                        name=d_domain+'._device-info._tcp.local.',
+                        addresses=b_ips,
+                        port=80,
+                        server=d+'.',
+                    )
+                )
+                infos.append(
+                    AsyncServiceInfo(
+                        type_='_http._tcp.local.',
+                        name=d_domain+'._http._tcp.local.',
                         addresses=b_ips,
                         port=80,
                         server=d+'.',
                     )
                 )
                 print('Adding '+d+' with addresses '+str(ips)+' on interface '+interface)
-
-        # Create an AsyncZeroconf object, store it, and start Service registration
+            # Create an AsyncZeroconf object, and store registration task
             aiozc = AsyncZeroconf(interfaces=ips)
-        aiozcs.append(aiozc)
-        print("Registration on interface "+interface+"...")
-        loop = asyncio.get_event_loop()
-        loop.run_until_complete(register_services(aiozc, infos))
+            aiozcs[aiozc]=infos
+
+    # Run registration
+    loop.run_until_complete(register_services(aiozcs))
+    print("Registration complete. Press Ctrl-c or stop service to exit...")
 
-    # We are done looping among the interfaces
-    print("Registration complete. Press Ctrl-c to exit...")
     try:
         while True:
-            time.sleep(0.1)
+            time.sleep(1)
     except KeyboardInterrupt:
         pass
     finally:
         print("Unregistering...")
-        for aiozc in aiozcs:
-            loop.run_until_complete(unregister_services(aiozc, infos))
-            loop.run_until_complete(close_aiozc(aiozc))
+        loop.run_until_complete(unregister_services(aiozcs))
         print("Unregistration complete.")
+        loop.run_until_complete(close_aiozcs(aiozcs))
 

data/hooks/conf_regen/01-yunohost

@@ -3,6 +3,7 @@
 set -e
 
 services_path="/etc/yunohost/services.yml"
+mdns_path="/etc/yunohost/mdns.yml"
 
 do_init_regen() {
   if [[ $EUID -ne 0 ]]; then
@@ -18,9 +19,11 @@ do_init_regen() {
   [[ -f /etc/yunohost/current_host ]] \
     || echo "yunohost.org" > /etc/yunohost/current_host
 
-  # copy default services and firewall
+  # copy default services, mdns, and firewall
   [[ -f $services_path ]] \
     || cp services.yml "$services_path"
+  [[ -f $mdns_path ]] \
+    || cp mdns.yml "$mdns_path"
   [[ -f /etc/yunohost/firewall.yml ]] \
     || cp firewall.yml /etc/yunohost/firewall.yml
 

data/other/yunomdns.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=YunoHost mDNS service
+After=network.target
+
+[Service]
+User=avahi
+Group=avahi
+Type=simple
+ExecStart=/usr/bin/yunomdns
+StandardOutput=syslog
+
+[Install]
+WantedBy=default.target

data/templates/yunohost/mdns.yml

@@ -0,0 +1,4 @@
+enabled: True
+regen: all
+interfaces:
+domains:

data/templates/yunohost/services.yml

@@ -52,6 +52,8 @@ yunohost-firewall:
   need_lock: true
   test_status: iptables -S | grep "^-A INPUT" | grep " --dport" | grep -q ACCEPT
   category: security
+yunomdns:
+  needs_exposed_ports: [5353]
 glances: null
 nsswitch: null
 ssl: null

debian/install

@@ -5,6 +5,7 @@ doc/yunohost.8.gz /usr/share/man/man8/
 data/actionsmap/* /usr/share/moulinette/actionsmap/
 data/hooks/* /usr/share/yunohost/hooks/
 data/other/yunoprompt.service /etc/systemd/system/
+data/other/yunomdns.service /etc/systemd/system/
 data/other/password/* /usr/share/yunohost/other/password/
 data/other/dpkg-origins/yunohost /etc/dpkg/origins
 data/other/dnsbl_list.yml /usr/share/yunohost/other/

debian/postinst

@@ -38,6 +38,10 @@ do_configure() {
 
   # Yunoprompt
   systemctl enable yunoprompt.service
+
+  # Yunomdns
+  chown avahi:avahi /etc/yunohost/mdns.yml
+  systemctl enable yunomdns.service
 }
 
 # summary of how this script can be called: