fix: add docker dns for ipv6 (#1115)

Author: ajasnosz

docker_compose/.env

@@ -6,6 +6,7 @@ TRAPS_CONFIG_FILE_ABSOLUTE_PATH=
 INVENTORY_FILE_ABSOLUTE_PATH=
 COREFILE_ABS_PATH=
 COREDNS_ADDRESS=172.28.0.255
+COREDNS_ADDRESS_IPv6=fd02:0:0:0:7fff:ffff:ffff:ffff
 SC4SNMP_VERSION="1.12.1-beta.2"
 IPv6_ENABLED=false
 

docker_compose/Corefile

@@ -3,5 +3,5 @@
     errors
     auto
     reload
-    forward . 8.8.8.8
+    forward . 8.8.8.8 2001:4860:4860::8888
 }

docker_compose/docker-compose.yaml

@@ -47,6 +47,7 @@ x-dns_and_networks: &dns_and_networks
   - sc4snmp_network
   dns:
   - ${COREDNS_ADDRESS}
+  - ${COREDNS_ADDRESS_IPv6}
 
 x-dependency_and_restart_policy: &dependency_and_restart_policy
   depends_on:
@@ -86,6 +87,7 @@ services:
     networks:
       sc4snmp_network:
         ipv4_address: ${COREDNS_ADDRESS}
+        ipv6_address: ${COREDNS_ADDRESS_IPv6}
   snmp-mibserver:
     <<: [*dns_and_networks, *dependend_on_core_dns]
     image: ${MIBSERVER_IMAGE}:${MIBSERVER_TAG:-latest}

docs/dockercompose/6-env-file-configuration.md

@@ -13,6 +13,7 @@ Inside the directory with the docker compose files, there is a `.env`. Variables
 | `INVENTORY_FILE_ABSOLUTE_PATH`        | Absolute path to [inventory.csv](./3-inventory-configuration.md) file                                |
 | `COREFILE_ABS_PATH`                   | Absolute path to Corefile used by coreDNS. Default Corefile can be found inside the `docker_compose` |
 | `COREDNS_ADDRESS`                     | IP address of the coredns inside docker network. Should not be changed                               |
+| `COREDNS_ADDRESS_IPv6`                | IPv6 address of the coredns inside docker network. Should not be changed                             |
 | `SC4SNMP_VERSION`                     | Version of SC4SNMP                                                                                   |
 | `IPv6_ENABLED`                        | Enable receiving traps and polling from IPv6 devices                                                 |
 

docs/microk8s/configuration/poller-configuration.md

@@ -31,6 +31,9 @@ poller:
 !!! info
     The header's line (`address,port,version,community,secret,security_engine,walk_interval,profiles,smart_profiles,delete`) is necessary for the correct execution of SC4SNMP. Do not remove it.
 
+### IPv6 hostname resolution
+When IPv6 is enabled and device is dual stack, the hostname resolution will try to resolve the name to the IPv6 address first, then to the IPv4 address.
+
 ### Define log level
 The log level for poller can be set by changing the value for the key `logLevel`. The allowed values are: `DEBUG`, `INFO`, `WARNING`, `ERROR`, `CRITICAL` or `FATAL`. 
 The default value is `INFO`.

integration_tests/.env

@@ -6,8 +6,9 @@ TRAPS_CONFIG_FILE_ABSOLUTE_PATH=
 INVENTORY_FILE_ABSOLUTE_PATH=
 COREFILE_ABS_PATH=
 COREDNS_ADDRESS=172.28.0.255
-SC4SNMP_VERSION="1.11.0-beta.9"
-
+COREDNS_ADDRESS_IPv6=fd02:0:0:0:7fff:ffff:ffff:ffff
+SC4SNMP_VERSION=latest
+IPv6_ENABLED=false
 
 # Dependencies images
 COREDNS_IMAGE=coredns/coredns
@@ -81,6 +82,7 @@ CHAIN_OF_TASKS_EXPIRY_TIME=500
 # Traps configuration
 SNMP_V3_SECURITY_ENGINE_ID=80003a8c04
 TRAPS_PORT=162
+IPv6_TRAPS_PORT=2163
 TRAP_LOG_LEVEL=INFO
 
 # Scheduler configuration

integration_tests/automatic_setup_compose.sh

@@ -48,6 +48,7 @@ deploy_poetry() {
 }
 
 wait_for_containers_to_be_up() {
+  echo $(sudo docker ps)
   while true; do
     CONTAINERS_SC4SNMP=$(sudo docker ps | grep "sc4snmp\|worker-poller\|worker-sender\|worker-trap" | grep -v "Name" | wc -l)
     if [ "$CONTAINERS_SC4SNMP" -gt 0 ]; then

splunk_connect_for_snmp/common/inventory_record.py

@@ -33,8 +33,8 @@
 
 
 class InventoryRecord(BaseModel):
-    address: InventoryStr
     port: InventoryInt = 161
+    address: InventoryStr
     version: InventoryStr
     community: InventoryStr
     secret: InventoryStr
@@ -53,7 +53,7 @@ def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
     @validator("address", pre=True)
-    def address_validator(cls, value):
+    def address_validator(cls, value, values):
         if value is None:
             raise ValueError("field address cannot be null")
         if value.startswith("#"):
@@ -63,7 +63,7 @@ def address_validator(cls, value):
                 ip_address(value)
             except ValueError:
                 try:
-                    socket.gethostbyname_ex(value)
+                    socket.getaddrinfo(value, values["port"])
                 except socket.gaierror:
                     raise ValueError(
                         f"field address must be an IP or a resolvable hostname {value}"

splunk_connect_for_snmp/snmp/auth.py

@@ -14,6 +14,8 @@
 # limitations under the License.
 #
 import os
+import socket
+from ipaddress import ip_address
 from typing import Any, Dict, Union
 
 from pysnmp.hlapi import (
@@ -28,11 +30,13 @@
 from pysnmp.proto.api.v2c import OctetString
 from pysnmp.smi.rfc1902 import ObjectIdentity, ObjectType
 
+from splunk_connect_for_snmp.common.hummanbool import human_bool
 from splunk_connect_for_snmp.common.inventory_record import InventoryRecord
 from splunk_connect_for_snmp.snmp.const import AuthProtocolMap, PrivProtocolMap
 from splunk_connect_for_snmp.snmp.exceptions import SnmpActionError
 
 UDP_CONNECTION_TIMEOUT = int(os.getenv("UDP_CONNECTION_TIMEOUT", 1))
+IPv6_ENABLED = human_bool(os.getenv("IPv6_ENABLED", False))
 
 
 def get_secret_value(
@@ -87,7 +91,8 @@ def get_security_engine_id(logger, ir: InventoryRecord, snmp_engine: SnmpEngine)
 
 
 def setup_transport_target(ir):
-    if ":" in ir.address:
+    ip = get_ip_from_socket(ir) if IPv6_ENABLED else ir.address
+    if ip_address(ip).version == 6:
         transport = Udp6TransportTarget(
             (ir.address, ir.port), timeout=UDP_CONNECTION_TIMEOUT
         )
@@ -98,6 +103,13 @@ def setup_transport_target(ir):
     return transport
 
 
+def get_ip_from_socket(ir):
+    # Example of response from getaddrinfo
+    # [(< AddressFamily.AF_INET6: 10 >, < SocketKind.SOCK_STREAM: 1 >, 6, '', ('2607:f8b0:4004:c09::64', 161, 0, 0)),
+    # (< AddressFamily.AF_INET: 2 >, < SocketKind.SOCK_STREAM: 1 >, 6, '', ('142.251.16.139', 161))]
+    return socket.getaddrinfo(ir.address, ir.port)[0][4][0]
+
+
 def fetch_security_engine_id(observer_context, error_indication, ipaddress):
     if "securityEngineId" in observer_context:
         return observer_context["securityEngineId"]