Do not pin NIC name if `net.ifnames=0`

Resolves: RHBZ#2182769

Signed-off-by: Gris Ge <fge@redhat.com>

BZ_2182769-skip_if_ifnetifnames_0.patch

@@ -0,0 +1,62 @@
+From d8b4c29ab17a53bad6f189acf76bab78e29ee333 Mon Sep 17 00:00:00 2001
+From: Gris Ge <fge@redhat.com>
+Date: Sun, 23 Apr 2023 16:01:29 +0800
+Subject: [PATCH] cli: Do nothing for `persist-nic-names` when got
+ `net.ifnames=0`
+
+When `net.ifnames=0` is defined in kernel argument, systemd will disable
+the predicable network interface name which make no sense for nmstate to
+pin the interface names. Hence we do nothing in `persist-nic-names` in
+that case.
+
+Manually tested in CentOS stream 9 VM.
+
+Signed-off-by: Gris Ge <fge@redhat.com>
+---
+ rust/src/cli/persist_nic.rs | 19 +++++++++++++++++++
+ 1 file changed, 19 insertions(+)
+
+diff --git a/rust/src/cli/persist_nic.rs b/rust/src/cli/persist_nic.rs
+index 6b126d58..61b07dbb 100644
+--- a/rust/src/cli/persist_nic.rs
++++ b/rust/src/cli/persist_nic.rs
+@@ -7,6 +7,8 @@
+ //!
+ //! The logic currently is:
+ //!
++//!  - Do nothing if kernel argument contains `net.ifnames=0` which disabled the
++//!    predicable network interface name, hence not fit our use case here.
+ //!  - Iterate over all active NICs
+ //!  - Pin every ethernet interface to its MAC address (prefer permanent MAC
+ //!    address)
+@@ -70,6 +72,14 @@ pub(crate) fn run_persist_immediately(
+         PersistAction::CleanUpDryRun => return clean_up(root, true),
+     };
+ 
++    if is_prediable_ifname_disabled() {
++        log::info!(
++            "Systemd predicable network interface name is disabled \
++            by kernel argument `net.ifnames=0`, will do nothing"
++        );
++        return Ok("".to_string());
++    }
++
+     let stamp_path = Path::new(root)
+         .join(SYSTEMD_NETWORK_LINK_FOLDER)
+         .join(NMSTATE_PERSIST_STAMP);
+@@ -317,3 +327,12 @@ fn is_nmstate_generated_systemd_link_file(file_path: &PathBuf) -> bool {
+         .map(|_| buff == PERSIST_GENERATED_BY.as_bytes())
+         .unwrap_or_default()
+ }
++
++const KERNEL_CMDLINE_FILE: &str = "/proc/cmdline";
++
++fn is_prediable_ifname_disabled() -> bool {
++    std::fs::read(KERNEL_CMDLINE_FILE)
++        .map(|v| String::from_utf8(v).unwrap_or_default())
++        .map(|c| c.contains("net.ifnames=0"))
++        .unwrap_or_default()
++}
+-- 
+2.40.0
+

nmstate.spec

@@ -4,7 +4,7 @@
 
 Name:           nmstate
 Version:        2.2.10
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        Declarative network manager API
 License:        LGPLv2+
 URL:            https://github.com/%{srcname}/%{srcname}
@@ -12,6 +12,7 @@ Source0:        https://github.com/nmstate/nmstate/releases/download/v%{version}
 Source1:        https://github.com/nmstate/nmstate/releases/download/v%{version}/nmstate-%{version}.tar.gz.asc
 Source2:        https://nmstate.io/nmstate.gpg
 Source3:        https://github.com/nmstate/nmstate/releases/download/v%{version}/nmstate-vendor-%{version}.tar.xz
+Patch1:         BZ_2182769-skip_if_ifnetifnames_0.patch
 BuildRequires:  python3-devel
 BuildRequires:  python3-setuptools
 BuildRequires:  gnupg2
@@ -150,6 +151,9 @@ popd
 /sbin/ldconfig
 
 %changelog
+* Sun Apr 23 2023 Gris Ge <fge@redhat.com> - 2.2.10-2
+- Do not pin NIC if `net.ifnames=0`
+
 * Thu Mar 23 2023 Gris Ge <fge@redhat.com> - 2.2.9-1
 - Upgrade to 2.2.9