Add some tests to verify Redis DB configuration (#12877)

* Add test to verify that the redis DB is not being saved to disk

Add a test script to check that the redis config for the save setting is
correct. This can be extended to check for other config options.


Signed-off-by: Saikrishna Arcot <sarcot@microsoft.com>

.azure-pipelines/pr_test_scripts.yaml

@@ -22,6 +22,7 @@ t0:
   - console/test_console_udevrule.py
   - container_checker/test_container_checker.py
   - container_hardening/test_container_hardening.py
+  - database/test_db_config.py
   - database/test_db_scripts.py
   - dhcp_relay/test_dhcp_pkt_recv.py
   - dhcp_relay/test_dhcp_relay.py

tests/database/test_db_config.py

@@ -0,0 +1,50 @@
+"""
+Test the database config
+"""
+import logging
+import pytest
+import json
+
+from tests.common.helpers.assertions import pytest_assert
+
+logger = logging.getLogger(__name__)
+
+pytestmark = [
+    pytest.mark.topology('any')
+]
+
+
+def test_redis_save_disabled(duthosts, rand_one_dut_hostname):
+    """
+    @summary: Test that the database isn't being saved to disk
+    """
+    duthost = duthosts[rand_one_dut_hostname]
+
+    save_config_json = duthost.command(argv=["redis-cli", "--json", "CONFIG", "GET", "save"])["stdout"]
+    save_config = json.loads(save_config_json)
+    pytest_assert(save_config["save"] == "", "Redis should not be persisting contents to disk, save config is {}"
+                  .format(save_config["save"]))
+
+
+def test_redis_database_count(duthosts, rand_one_dut_hostname):
+    """
+    @summary: Test that redis is configured to support 100 databases
+    """
+    duthost = duthosts[rand_one_dut_hostname]
+
+    database_config_json = duthost.command(argv=["redis-cli", "--json", "CONFIG", "GET", "databases"])["stdout"]
+    database_config = json.loads(database_config_json)
+    pytest_assert(database_config["databases"] == "100", "Redis is configured to support {} instead of 100 databases"
+                  .format(database_config["databases"]))
+
+
+def test_redis_unix_socket(duthosts, rand_one_dut_hostname):
+    """
+    @summary: Test that redis has the unix socket option enabled
+    """
+    duthost = duthosts[rand_one_dut_hostname]
+
+    unixsocket_config_json = duthost.command(argv=["redis-cli", "--json", "CONFIG", "GET", "unixsocket"])["stdout"]
+    unixsocket_config = json.loads(unixsocket_config_json)
+    pytest_assert(unixsocket_config["unixsocket"] == "/var/run/redis/redis.sock",
+                  "Redis unixsocket is not configured correctly")

tests/kvmtest.sh

@@ -174,6 +174,7 @@ test_t0() {
       show_techsupport/test_techsupport_no_secret.py \
       system_health/test_system_status.py \
       radv/test_radv_ipv6_ra.py \
+      database/test_db_config.py \
       database/test_db_scripts.py"
 
       pushd $SONIC_MGMT_DIR/tests