sonic: make the port_config path configurable (#2563)

The directory holding the per-HWSKU port_config .ini files was hardcoded
to /etc/sonic/port_config, which only exists inside the conductor image
-- the Containerfile copies files/sonic/port_config there. A generator
run from a checkout instead, as in local development, finds nothing at
that path, and planting the files under /etc/sonic to work around it
needs root.

Introduce a SONIC_PORT_CONFIG_PATH setting in osism.settings, following
the existing SONIC_* environment variable convention, and wire
constants.PORT_CONFIG_PATH to it. The default is the previous hardcoded
path, so container behaviour is identical; setting the variable points
the generator at files/sonic/port_config/ in the checkout instead.

Tests cover the default, the environment override, and the
settings-to-constants wiring.

Assisted-by: Claude:claude-sonnet-5

Signed-off-by: Roger Luethi <luethi@osism.tech>

Author: berendt

osism/settings.py

@@ -78,6 +78,10 @@ def read_secret(secret_name):
 SONIC_EXPORT_SUFFIX = os.getenv("SONIC_EXPORT_SUFFIX", "_config_db.json")
 SONIC_EXPORT_IDENTIFIER = os.getenv("SONIC_EXPORT_IDENTIFIER", "serial-number")
 
+# Directory holding the per-HWSKU port_config .ini files (bundled in the
+# repo under files/sonic/port_config and installed by the Dockerfile)
+SONIC_PORT_CONFIG_PATH = os.getenv("SONIC_PORT_CONFIG_PATH", "/etc/sonic/port_config")
+
 # SONiC ZTP firmware configuration
 #
 # The ZTP firmware install uses a dynamic-url built from

osism/tasks/conductor/sonic/constants.py

@@ -2,6 +2,8 @@
 
 """Constants and mappings for SONiC configuration."""
 
+from osism import settings
+
 # Tag to add AF L2VPN EVPN to BGP neighbor
 BGP_AF_L2VPN_EVPN_TAG = "bgp-af-l2vpn-evpn"
 
@@ -87,7 +89,7 @@
 }
 
 # Path to SONiC port configuration files
-PORT_CONFIG_PATH = "/etc/sonic/port_config"
+PORT_CONFIG_PATH = settings.SONIC_PORT_CONFIG_PATH
 
 # List of supported vendors
 SUPPORTED_VENDORS = [

tests/unit/tasks/conductor/sonic/test_constants.py

@@ -1,7 +1,11 @@
 # SPDX-License-Identifier: Apache-2.0
 
+import importlib
+
 import pytest
 
+from osism import settings as settings_module
+from osism.tasks.conductor.sonic import constants as constants_module
 from osism.tasks.conductor.sonic.constants import (
     BGP_AF_L2VPN_EVPN_TAG,
     DEFAULT_LOCAL_AS_PREFIX,
@@ -151,3 +155,19 @@ def test_supported_hwskus_entry_invariants(hwsku):
     assert "-" in hwsku
     vendor = hwsku.split("-")[0]
     assert vendor in SUPPORTED_VENDORS
+
+
+# ---------------------------------------------------------------------------
+# PORT_CONFIG_PATH settings wiring
+# ---------------------------------------------------------------------------
+
+
+def test_port_config_path_follows_settings():
+    original = settings_module.SONIC_PORT_CONFIG_PATH
+    try:
+        settings_module.SONIC_PORT_CONFIG_PATH = "/custom/port_config"
+        reloaded = importlib.reload(constants_module)
+        assert reloaded.PORT_CONFIG_PATH == "/custom/port_config"
+    finally:
+        settings_module.SONIC_PORT_CONFIG_PATH = original
+        importlib.reload(constants_module)

tests/unit/test_settings.py

@@ -583,6 +583,20 @@ def test_sonic_export_identifier_override(reload_settings, monkeypatch):
     assert settings_module.SONIC_EXPORT_IDENTIFIER == "asset-tag"
 
 
+def test_sonic_port_config_path_default(reload_settings, monkeypatch):
+    monkeypatch.delenv("SONIC_PORT_CONFIG_PATH", raising=False)
+    reload_settings()
+
+    assert settings_module.SONIC_PORT_CONFIG_PATH == "/etc/sonic/port_config"
+
+
+def test_sonic_port_config_path_override(reload_settings, monkeypatch):
+    monkeypatch.setenv("SONIC_PORT_CONFIG_PATH", "/tmp/port_config")
+    reload_settings()
+
+    assert settings_module.SONIC_PORT_CONFIG_PATH == "/tmp/port_config"
+
+
 # ---------------------------------------------------------------------------
 # NETBOX_SECONDARIES
 # ---------------------------------------------------------------------------