Update docs for master dns changes

Update docs to use master_alive_interval to detect master ip changes via
DNS.

conf/minion

@@ -271,9 +271,8 @@
 #ping_interval: 0
 
 # To auto recover minions if master changes IP address (DDNS)
-#    auth_tries: 10
-#    auth_safemode: True
-#    ping_interval: 2
+#    master_alive_interval: 10
+#    master_tries: -1
 #
 # Minions won't know master is missing until a ping fails. After the ping fail,
 # the minion will attempt authentication and likely fails out and cause a restart.

doc/ref/configuration/minion.rst

@@ -291,7 +291,9 @@ Default: ``0``
 
 Configures how often, in seconds, the minion will verify that the current
 master is alive and responding.  The minion will try to establish a connection
-to the next master in the list if it finds the existing one is dead.
+to the next master in the list if it finds the existing one is dead. This
+setting can also be used to detect master DNS record changes when a minion has
+been disconnected.
 
 .. code-block:: yaml
 

tests/pytests/scenarios/dns/conftest.py

@@ -7,6 +7,11 @@ import pytest
 log = logging.getLogger(__name__)
 
 
+@pytest.fixture(scope="package")
+def master_alive_interval():
+    return 5
+
+
 class HostsFile:
     """
     Simple helper class for tests that need to modify /etc/hosts.
@@ -70,7 +75,7 @@ def salt_cli(master):
 
 
 @pytest.fixture(scope="package")
-def minion(master):
+def minion(master, master_alive_interval):
     config_defaults = {
         "transport": master.config["transport"],
     }
@@ -78,9 +83,7 @@ def minion(master):
     config_overrides = {
         "master": f"master.local:{port}",
         "publish_port": master.config["publish_port"],
-        "master_alive_interval": 5,
-        "master_tries": -1,
-        "auth_safemode": False,
+        "master_alive_interval": master_alive_interval,
     }
     factory = master.salt_minion_daemon(
         "minion",

tests/pytests/scenarios/dns/multimaster/conftest.py

@@ -86,26 +86,23 @@ def mm_master_2_salt_cli(salt_mm_master_2):
 
 
 @pytest.fixture(scope="package")
-def salt_mm_minion_1(salt_mm_master_1, salt_mm_master_2):
+def salt_mm_minion_1(salt_mm_master_1, salt_mm_master_2, master_alive_interval):
     config_defaults = {
         "transport": salt_mm_master_1.config["transport"],
     }
 
     mm_master_1_port = salt_mm_master_1.config["ret_port"]
-    # mm_master_1_addr = salt_mm_master_1.config["interface"]
     mm_master_2_port = salt_mm_master_2.config["ret_port"]
-    # mm_master_2_addr = salt_mm_master_2.config["interface"]
     config_overrides = {
         "master": [
             f"master1.local:{mm_master_1_port}",
             f"master2.local:{mm_master_2_port}",
         ],
         "publish_port": salt_mm_master_1.config["publish_port"],
-        # "master_type": "failover",
-        "master_alive_interval": 5,
+        "master_alive_interval": master_alive_interval,
         "master_tries": -1,
         "verify_master_pubkey_sign": True,
-        "retry_dns": 1,
+        "retry_dns": True,
     }
     factory = salt_mm_master_1.salt_minion_daemon(
         "mm-minion-1",
@@ -120,41 +117,3 @@ def salt_mm_minion_1(salt_mm_master_1, salt_mm_master_2):
     )
     # with factory.started(start_timeout=180):
     yield factory
-
-
-@pytest.fixture(scope="package")
-def salt_mm_minion_2(salt_mm_master_1, salt_mm_master_2):
-    config_defaults = {
-        "transport": salt_mm_master_1.config["transport"],
-    }
-
-    mm_master_1_port = salt_mm_master_1.config["ret_port"]
-    mm_master_1_addr = salt_mm_master_1.config["interface"]
-    mm_master_2_port = salt_mm_master_2.config["ret_port"]
-    mm_master_2_addr = salt_mm_master_2.config["interface"]
-    # We put the second master first in the list so it has the right startup checks every time.
-    config_overrides = {
-        "master": [
-            f"{mm_master_2_addr}:{mm_master_2_port}",
-            f"{mm_master_1_addr}:{mm_master_1_port}",
-        ],
-        "publish_port": salt_mm_master_1.config["publish_port"],
-        "master_type": "failover",
-        "master_alive_interval": 5,
-        "master_tries": -1,
-        "verify_master_pubkey_sign": True,
-        "retry_dns": 1,
-    }
-    factory = salt_mm_master_2.salt_minion_daemon(
-        "mm-failover-minion-2",
-        defaults=config_defaults,
-        overrides=config_overrides,
-        extra_cli_arguments_after_first_start_failure=["--log-level=info"],
-    )
-    # Need to grab the public signing key from the master, either will do
-    shutil.copyfile(
-        os.path.join(salt_mm_master_1.config["pki_dir"], "master_sign.pub"),
-        os.path.join(factory.config["pki_dir"], "master_sign.pub"),
-    )
-    # with factory.started(start_timeout=180):
-    yield factory

tests/pytests/scenarios/dns/multimaster/test_dns.py

@@ -9,7 +9,12 @@ log = logging.getLogger(__name__)
 
 @pytest.mark.skip_unless_on_linux
 def test_multimaster_dns(
-    salt_mm_master_1, salt_mm_minion_1, mm_master_1_salt_cli, etc_hosts, caplog
+    salt_mm_master_1,
+    salt_mm_minion_1,
+    mm_master_1_salt_cli,
+    etc_hosts,
+    caplog,
+    master_alive_interval,
 ):
     """
     Verify a minion configured with multimaster hot/hot will pick up a master's
@@ -26,13 +31,15 @@ def test_multimaster_dns(
         with caplog.at_level(logging.INFO):
             ret = mm_master_1_salt_cli.run("test.ping", minion_tgt="mm-minion-1")
             assert ret.returncode == 0
-            log.info("Removing secondary master IP address.")
             etc_hosts.write_text(
                 f"{etc_hosts.orig_text}\n127.0.0.1    master1.local master2.local"
             )
-            subprocess.check_output(["ip", "addr", "del", "172.16.0.1/32", "dev", "lo"])
             log.info("Changed hosts record for master1.local and master2.local")
-            time.sleep(15)
+            subprocess.check_output(["ip", "addr", "del", "172.16.0.1/32", "dev", "lo"])
+            log.info("Removed secondary master IP address.")
+            # Wait for the minion's master_alive_interval, adding a second for
+            # reliablity.
+            time.sleep(master_alive_interval + 1)
             assert (
                 "Master ip address changed from 172.16.0.1 to 127.0.0.1" in caplog.text
             )

tests/pytests/scenarios/dns/test_dns.py

@@ -8,7 +8,7 @@ log = logging.getLogger(__name__)
 
 
 @pytest.mark.skip_unless_on_linux
-def test_dns_change(master, minion, salt_cli, etc_hosts, caplog):
+def test_dns_change(master, minion, salt_cli, etc_hosts, caplog, master_alive_interval):
     """
     Verify a minion will pick up a master's dns change if it's been disconnected.
     """
@@ -20,8 +20,12 @@ def test_dns_change(master, minion, salt_cli, etc_hosts, caplog):
             ret = salt_cli.run("test.ping", minion_tgt="minion")
             assert ret.returncode == 0
             etc_hosts.write_text(f"{etc_hosts.orig_text}\n127.0.0.1    master.local")
+            log.info("Changed hosts record for master1.local and master2.local")
             subprocess.check_output(["ip", "addr", "del", "172.16.0.1/32", "dev", "lo"])
-            time.sleep(15)
+            log.info("Removed secondary master IP address.")
+            # Wait for the minion's master_alive_interval, adding a second for
+            # reliablity.
+            time.sleep(master_alive_interval + 1)
             assert (
                 "Master ip address changed from 172.16.0.1 to 127.0.0.1" in caplog.text
             )