Autodetect NOS (fixes #13)

netlint/checks/checker.py

@@ -2,6 +2,8 @@
 import functools
 import typing
 
+from netlint.utils import NOS
+
 
 class CheckResult(typing.NamedTuple):
     """Result of a single check."""
@@ -26,15 +28,15 @@ class Checker:
     """Class to handle check execution."""
 
     # Map NOSes to applicable checks
-    checks: typing.Dict[str, typing.List[CheckFunctionTuple]] = {}
+    checks: typing.Dict[NOS, typing.List[CheckFunctionTuple]] = {}
 
     def __init__(self) -> None:
         # Map check name to check result (NOS-agnostic)
         self.check_results: typing.Dict[str, typing.Optional[CheckResult]] = {}
 
     @classmethod
     def register(
-        cls, apply_to: typing.List[str], name: str
+        cls, apply_to: typing.List[NOS], name: str
     ) -> typing.Callable[
         [typing.Callable[[typing.List[str]], typing.Optional[CheckResult]]],
         typing.Callable[[typing.List[str]], typing.Optional[CheckResult]],
@@ -80,7 +82,7 @@ def wrapper(config: typing.List[str]) -> typing.Optional[CheckResult]:
 
         return decorator
 
-    def run_checks(self, configuration: typing.List[str], nos: str) -> bool:
+    def run_checks(self, configuration: typing.List[str], nos: NOS) -> bool:
         """
         Run all the registered checks on the configuration.
 

netlint/checks/cisco_ios/__init__.py

@@ -10,12 +10,14 @@
     "check_plaintext_passwords",
     "check_console_password",
     "check_ip_http_server",
+    "check_password_hash_strength",
 ]
 
 from netlint.checks.cisco_ios.utils import get_password_hash_algorithm
+from netlint.utils import NOS
 
 
-@Checker.register(apply_to=["cisco_ios"], name="IOS101")
+@Checker.register(apply_to=[NOS.CISCO_IOS], name="IOS101")
 def check_plaintext_passwords(config: typing.List[str]) -> typing.Optional[CheckResult]:
     """Check if there are any plaintext passwords in the configuration."""
     parsed_config = CiscoConfParse(config)
@@ -39,7 +41,7 @@ def check_plaintext_passwords(config: typing.List[str]) -> typing.Optional[Check
         return None
 
 
-@Checker.register(apply_to=["cisco_ios"], name="IOS102")
+@Checker.register(apply_to=[NOS.CISCO_IOS], name="IOS102")
 def check_ip_http_server(config: typing.List[str]) -> typing.Optional[CheckResult]:
     """Check if the http server is enabled."""
     parsed_config = CiscoConfParse(config)
@@ -50,7 +52,7 @@ def check_ip_http_server(config: typing.List[str]) -> typing.Optional[CheckResul
         return None
 
 
-@Checker.register(apply_to=["cisco_ios"], name="IOS103")
+@Checker.register(apply_to=[NOS.CISCO_IOS], name="IOS103")
 def check_console_password(config: typing.List[str]) -> typing.Optional[CheckResult]:
     """Check for authentication on the console line."""
     parsed_config = CiscoConfParse(config)
@@ -72,7 +74,7 @@ def check_console_password(config: typing.List[str]) -> typing.Optional[CheckRes
         return None
 
 
-@Checker.register(apply_to=["cisco_ios"], name="IOS104")
+@Checker.register(apply_to=[NOS.CISCO_IOS], name="IOS104")
 def check_password_hash_strength(
     config: typing.List[str],
 ) -> typing.Optional[CheckResult]:

netlint/checks/cisco_nxos/__init__.py

@@ -13,9 +13,10 @@
 ]
 
 from netlint.checks.constants import bogus_as_numbers
+from netlint.utils import NOS
 
 
-@Checker.register(apply_to=["cisco_nxos"], name="NXOS101")
+@Checker.register(apply_to=[NOS.CISCO_NXOS], name="NXOS101")
 def check_telnet_enabled(config: typing.List[str]) -> typing.Optional[CheckResult]:
     """Check if the telnet feature is explicitly enabled."""
     parsed_config = CiscoConfParse(config)
@@ -26,7 +27,7 @@ def check_telnet_enabled(config: typing.List[str]) -> typing.Optional[CheckResul
         return None
 
 
-@Checker.register(apply_to=["cisco_nxos"], name="NXOS102")
+@Checker.register(apply_to=[NOS.CISCO_NXOS], name="NXOS102")
 def check_routing_protocol_enabled_and_used(
     config: typing.List[str],
 ) -> typing.Optional[CheckResult]:
@@ -46,7 +47,7 @@ def check_routing_protocol_enabled_and_used(
     return None
 
 
-@Checker.register(apply_to=["cisco_nxos"], name="NXOS103")
+@Checker.register(apply_to=[NOS.CISCO_NXOS], name="NXOS103")
 def check_password_strength(config: typing.List[str]) -> typing.Optional[CheckResult]:
     """Check if the password strength check has been disabled."""
     parsed_config = CiscoConfParse(config)
@@ -57,7 +58,7 @@ def check_password_strength(config: typing.List[str]) -> typing.Optional[CheckRe
         return None
 
 
-@Checker.register(apply_to=["cisco_nxos"], name="NXOS104")
+@Checker.register(apply_to=[NOS.CISCO_NXOS], name="NXOS104")
 def check_bogus_as(config: typing.List[str]) -> typing.Optional[CheckResult]:
     """Check if any bogus autonomous system is used in the configuration."""
     parsed_config = CiscoConfParse(config)

netlint/checks/various/__init__.py

@@ -8,8 +8,10 @@
 
 __all__ = ["check_default_snmp_communities"]
 
+from netlint.utils import NOS
 
-@Checker.register(apply_to=["cisco_ios", "cisco_nxos"], name="VAR101")
+
+@Checker.register(apply_to=[NOS.CISCO_IOS, NOS.CISCO_NXOS], name="VAR101")
 def check_default_snmp_communities(
     config: typing.List[str],
 ) -> typing.Optional[CheckResult]:

netlint/main.py

@@ -8,7 +8,7 @@
 
 from netlint.checks.checker import Checker
 from netlint.types import JSONOutputDict
-from netlint.utils import smart_open, style
+from netlint.utils import smart_open, style, detect_nos, NOS
 
 CONTEXT_SETTINGS = {"help_option_names": ["-h", "--help"]}
 DEFAULT_CONFIG = "pyproject.toml"
@@ -87,11 +87,6 @@ def configure(
     type=click.Choice(["json", "normal"]),
     help="The format of the output data (--format json implies --quiet).",
 )
-@click.option(
-    "--nos",
-    type=click.Choice(["cisco_ios", "cisco_nxos"]),
-    help="The NOS the configuration(s) is/are for.",
-)
 @click.option(
     "--select",
     type=str,
@@ -139,7 +134,6 @@ def cli(
     prefix: str,
     output: typing.Optional[str],
     format_: str,
-    nos: str,
     select: typing.Optional[str],
     exclude: typing.Optional[str],
     quiet: bool,
@@ -160,24 +154,42 @@ def cli(
 
     checker_instance = Checker()
 
+    configurations: typing.Dict[str, typing.List[str]] = {"default": []}
+
+    input_path = Path(path)
+    nos_mapping = {"default": None}
+    if input_path.is_file():
+        with open(input_path) as f:
+            configurations["default"] = f.readlines()
+        nos_mapping["default"] = detect_nos(configurations["default"])
+    elif input_path.is_dir():
+        path_items = input_path.glob(glob)
+        for item in path_items:
+            dict_key = str(item)
+            with open(item) as f:
+                configurations[dict_key] = f.readlines()
+            nos_mapping[dict_key] = detect_nos(configurations[dict_key])
+
     if select:
         selected_checks = []
-        for check in checker_instance.checks[nos]:
+        for check in checker_instance.checks[nos_mapping["default"]]:
             if check.name in select.split(","):
                 selected_checks.append(check)
-        checker_instance.checks[nos] = selected_checks
+        checker_instance.checks[nos_mapping["default"]] = selected_checks
     elif exclude:
         excluded_checks = []
-        for check in checker_instance.checks[nos]:
-            if check.name in exclude.split(","):
-                excluded_checks.append(check)
+        # Iterate over each unique NOS
+        for nos in set(nos_mapping.values()):
+            for check in checker_instance.checks[nos]:
+                if check.name in exclude.split(","):
+                    excluded_checks.append(check)
         for check in excluded_checks:
-            checker_instance.checks[nos].remove(check)
-
-    input_path = Path(path)
+            checker_instance.checks[nos_mapping["default"]].remove(check)
 
     if input_path.is_file():
-        processed_config = check_config(checker_instance, input_path, nos)
+        processed_config = check_config(
+            checker_instance, configurations["default"], nos_mapping["default"]
+        )
         if processed_config:
             has_errors = True
         with smart_open(output) as f:
@@ -189,7 +201,9 @@ def cli(
         path_items = input_path.glob(glob)
         processed_configs: typing.Dict[str, JSONOutputDict] = {}
         for item in path_items:
-            processed_configs[str(item)] = check_config(checker_instance, item, nos)
+            processed_configs[str(item)] = check_config(
+                checker_instance, configurations[str(item)], nos_mapping[str(item)]
+            )
         if processed_configs:
             has_errors = True
         with smart_open(output) as f:
@@ -219,12 +233,12 @@ def cli(
         ctx.exit(0)
 
 
-def check_config(checker_instance: Checker, path: Path, nos: str) -> JSONOutputDict:
+def check_config(
+    checker_instance: Checker, configuration: typing.List[str], nos: NOS
+) -> JSONOutputDict:
     """Run checks on config at a given path."""
     return_value: JSONOutputDict = {}
 
-    with open(path, "r") as f:
-        configuration = f.readlines()
     checker_instance.run_checks(configuration, nos)
 
     for check, result in checker_instance.check_results.items():

netlint/utils.py

@@ -2,6 +2,7 @@
 import contextlib
 import sys
 import typing
+from enum import Enum
 
 import click
 
@@ -28,3 +29,21 @@ def style(message: str, quiet: bool, **kwargs: typing.Any) -> str:
         return message
     else:
         return click.style(message, **kwargs)
+
+
+class NOS(Enum):
+    """Overview of different available NOSes."""
+
+    CISCO_IOS = "cisco_ios"
+    CISCO_NXOS = "cisco_nxos"
+
+
+def detect_nos(configuration: typing.List[str]) -> NOS:
+    """Automatically detect the NOS in the configuration.
+
+    Very rudimentary as of now, will get more complex support for more NOSes is added.
+    """
+    for line in configuration:
+        if "feature" in line:
+            return NOS.CISCO_NXOS
+    return NOS.CISCO_IOS

tests/test_cli.py

@@ -17,7 +17,7 @@ def test_lint_basic(quiet: bool, format_: str):
 
     cisco_ios_faulty_conf = TESTS_DIR / "cisco_ios" / "configurations" / "faulty.conf"
 
-    commands = ["--nos", "cisco_ios", str(cisco_ios_faulty_conf)]
+    commands = [str(cisco_ios_faulty_conf)]
 
     if quiet:
         commands.insert(0, "--quiet")