feat(kubernetes): Handle empty --kubeconfig-file (#3980)

Co-authored-by: Sergio <sergio@prowler.com>

docs/index.md

@@ -324,6 +324,8 @@ For non in-cluster execution, you can provide the location of the KubeConfig fil
 ```console
 prowler kubernetes --kubeconfig-file path
 ```
+???+ note
+    If no `--kubeconfig-file` is provided, Prowler will use the default KubeConfig file location (`~/.kube/config`).
 
 For in-cluster execution, you can use the supplied yaml to run Prowler as a job within a new Prowler namespace:
 ```console

prowler/providers/kubernetes/kubernetes_provider.py

@@ -3,6 +3,7 @@ import sys
 from argparse import Namespace
 
 from colorama import Fore, Style
+from kubernetes.config.config_exception import ConfigException
 
 from kubernetes import client, config
 from prowler.config.config import load_and_validate_config_file
@@ -124,19 +125,18 @@ class KubernetesProvider(Provider):
             Tuple: A tuple containing the API client and the context.
         """
         try:
-            if kubeconfig_file:
-                logger.info(f"Using kubeconfig file: {kubeconfig_file}")
+            logger.info(f"Using kubeconfig file: {kubeconfig_file}")
+            try:
                 config.load_kube_config(
-                    config_file=os.path.abspath(kubeconfig_file), context=input_context
+                    config_file=(
+                        os.path.abspath(kubeconfig_file)
+                        if kubeconfig_file != "~/.kube/config"
+                        else os.path.expanduser(kubeconfig_file)
+                    ),
+                    context=input_context,
                 )
-                if input_context:
-                    contexts = config.list_kube_config_contexts()[0]
-                    for context_item in contexts:
-                        if context_item["name"] == input_context:
-                            context = context_item
-                else:
-                    context = config.list_kube_config_contexts()[1]
-            else:
+            except ConfigException:
+                # If the kubeconfig file is not found, try to use the in-cluster config
                 logger.info("Using in-cluster config")
                 config.load_incluster_config()
                 context = {
@@ -146,6 +146,14 @@ class KubernetesProvider(Provider):
                         "user": "service-account-name",  # Also a placeholder
                     },
                 }
+            else:
+                if input_context:
+                    contexts = config.list_kube_config_contexts()[0]
+                    for context_item in contexts:
+                        if context_item["name"] == input_context:
+                            context = context_item
+                else:
+                    context = config.list_kube_config_contexts()[1]
             return KubernetesSession(api_client=client.ApiClient(), context=context)
         except Exception as error:
             logger.critical(

prowler/providers/kubernetes/lib/arguments/arguments.py

@@ -12,6 +12,7 @@ def init_parser(self):
         nargs="?",
         metavar="FILE_PATH",
         help="Path to the kubeconfig file to use for CLI requests. Not necessary for in-cluster execution.",
+        default="~/.kube/config",
     )
     k8s_auth_subparser.add_argument(
         "--context",

tests/lib/cli/parser_test.py

@@ -189,7 +189,7 @@ class Test_Parser:
         assert not parsed.list_compliance
         assert not parsed.list_compliance_requirements
         assert not parsed.list_categories
-        assert not parsed.kubeconfig_file
+        assert parsed.kubeconfig_file == "~/.kube/config"
         assert not parsed.context
         assert not parsed.namespace