oracle-ds: prefer system_cfg over ds network config source (#1998)

Bump system_cfg over ds network_config_source for Oracle DS,
so that if network config is defined under /etc/cloud,
it will be honored.

In a previous change, we moved the initramfs and system_cfg
bellow ds to favor ds, but this implied system-wide configs
were always not honored.

LP: #1956788

3 files changed, 49 insertions, 1 deletions

diff --git a/cloudinit/sources/DataSourceOracle.py b/cloudinit/sources/DataSourceOracle.py
index 7f43b9e2..b88b55e2 100644
--- a/cloudinit/sources/DataSourceOracle.py
+++ b/cloudinit/sources/DataSourceOracle.py
@@ -118,9 +118,9 @@ class DataSourceOracle(sources.DataSource):
     vendordata_pure = None
     network_config_sources: Tuple[sources.NetworkConfigSource, ...] = (
         sources.NetworkConfigSource.CMD_LINE,
+        sources.NetworkConfigSource.SYSTEM_CFG,
         sources.NetworkConfigSource.DS,
         sources.NetworkConfigSource.INITRAMFS,
-        sources.NetworkConfigSource.SYSTEM_CFG,
     )
 
     _network_config: dict = {"config": [], "version": 1}
diff --git a/tests/integration_tests/datasources/test_oci_networking.py b/tests/integration_tests/datasources/test_oci_networking.py
index f569650e..dc0d343b 100644
--- a/tests/integration_tests/datasources/test_oci_networking.py
+++ b/tests/integration_tests/datasources/test_oci_networking.py
@@ -116,3 +116,42 @@ def test_oci_networking_iscsi_instance_secondary_vnics(
     )
     assert len(expected_interfaces) + 1 == len(configured_interfaces)
     assert client.execute("ping -c 2 canonical.com").ok
+
+
+SYSTEM_CFG = """\
+network:
+  ethernets:
+    id0:
+      dhcp4: true
+      dhcp6: true
+      match:
+        name: "ens*"
+  version: 2
+"""
+
+
+def customize_netcfg(
+    client: IntegrationInstance,
+    tmpdir,
+):
+    cfg = tmpdir.join("net.cfg")
+    with open(cfg, "w") as f:
+        f.write(SYSTEM_CFG)
+    client.push_file(cfg, "/etc/cloud/cloud.cfg.d/50-network-test.cfg")
+    client.execute("cloud-init clean --logs")
+    client.restart()
+
+
+@pytest.mark.oci
+def test_oci_networking_system_cfg(client: IntegrationInstance, tmpdir):
+    customize_netcfg(client, tmpdir)
+    log = client.read_from_file("/var/log/cloud-init.log")
+    verify_clean_log(log)
+
+    assert (
+        "Applying network configuration from system_cfg" in log
+    ), "network source used wasn't system_cfg"
+    netplan_yaml = client.read_from_file("/etc/netplan/50-cloud-init.yaml")
+    netplan_cfg = yaml.safe_load(netplan_yaml)
+    expected_netplan_cfg = yaml.safe_load(SYSTEM_CFG)
+    assert expected_netplan_cfg == netplan_cfg
diff --git a/tests/unittests/sources/test_oracle.py b/tests/unittests/sources/test_oracle.py
index e3648889..156bf9f5 100644
--- a/tests/unittests/sources/test_oracle.py
+++ b/tests/unittests/sources/test_oracle.py
@@ -1132,6 +1132,15 @@ class TestNetworkConfig:
         initramfs_idx = config_sources.index(NetworkConfigSource.INITRAMFS)
         assert ds_idx < initramfs_idx
 
+    def test_system_network_cfg_preferred_over_ds(
+        self, m_get_interfaces_by_mac
+    ):
+        """Ensure that system net config is preferred over DS config"""
+        config_sources = oracle.DataSourceOracle.network_config_sources
+        ds_idx = config_sources.index(NetworkConfigSource.DS)
+        system_idx = config_sources.index(NetworkConfigSource.SYSTEM_CFG)
+        assert system_idx < ds_idx
+
     @pytest.mark.parametrize("set_primary", [True, False])
     def test__add_network_config_from_opc_imds_no_vnics_data(
         self,