Add integration test for agent (#8094)

Author: mohamadaldawamnah

tests/suite/test_agent.py

@@ -1,6 +1,6 @@
 import pytest
 from kubernetes.stream import stream
-from suite.utils.resources_utils import get_first_pod_name, wait_before_test
+from suite.utils.resources_utils import get_file_contents, get_first_pod_name, wait_before_test
 
 
 @pytest.mark.agentv3
@@ -45,3 +45,49 @@ def test_agent(self, kube_apis, ingress_controller_prerequisites, ingress_contro
 
         assert f"Failed to get nginx-agent version: fork/exec /usr/bin/nginx-agent" not in log
         assert "nginx-agent version v3" in result_conf
+
+        # Test for agent.config file - verify the agent config exists inside the NIC pod
+        # The expected config that will be asserted against later
+        expected_config = """#
+# /etc/nginx-agent/nginx-agent.conf
+#
+# Configuration file for NGINX Agent.
+#
+
+log:
+  # set log level (error, warn, info, debug; default "info")
+  level: info
+  # set log path. if empty, don't log to file.
+  path: /var/log/nginx-agent/
+
+allowed_directories:
+    - /etc/nginx
+    - /usr/local/etc/nginx
+    - /usr/share/nginx/modules
+    - /var/run/nginx
+    - /var/log/nginx
+#
+# Command server settings to connect to a management plane server
+#
+#command:
+#  server:
+#    host: "agent.connect.nginx.com"
+#    port: 443
+#  auth:
+#    token: ""
+#  tls:
+#    skip_verify: false"""
+        expected_config = expected_config.strip()
+
+        # Get the actual config file content from the pod
+        config_contents = get_file_contents(
+            kube_apis.v1, "/etc/nginx-agent/nginx-agent.conf", pod_name, ingress_controller_prerequisites.namespace
+        )
+
+        # Normalize whitespace for comparison - remove trailing spaces from each line
+        def normalize_config(config_text):
+            return "\n".join(line.rstrip() for line in config_text.strip().split("\n"))
+
+        config_contents_normalized = normalize_config(config_contents)
+        expected_config_normalized = normalize_config(expected_config)
+        assert config_contents_normalized == expected_config_normalized