systemd: add initrd-specific services

Decouple from a specific initrd generator (dracut) the systemd services that
provide networking in the initrd using NM, thus allowing other systemd-based
initrd generators to take advantage of it.

These new services are:
- `NetworkManager-config-initrd.service`: it starts very early at boot, parses
the kernel command line using `nm-initrd-generator` and sets the
`/run/NetworkManager/initrd/neednet` flag to activate the other initrd services,
and also sets the hostname if needed.
- `NetworkManager-initrd.service`: it basically does the same job as the
`NetworkManager.service`, but in the initrd.
- `NetworkManager-wait-online-initrd.service`: ordered before
`network-online.target`, it will allow other services that require networking to
delay their start until NM has finished.

.gitignore

@@ -84,6 +84,9 @@ test-*.trs
 /data/org.freedesktop.NetworkManager.policy.in
 /data/nm-sudo.service
 /data/nm-priv-helper.service
+/data/NetworkManager-config-initrd.service
+/data/NetworkManager-initrd.service
+/data/NetworkManager-wait-online-initrd.service
 
 /docs/api/version.xml
 /docs/api/settings-spec.html

NEWS

@@ -8,6 +8,8 @@ subject to change and not guaranteed to be compatible with
 the later release.
 USE AT YOUR OWN RISK.  NOT RECOMMENDED FOR PRODUCTION USE!
 
+* Added systemd services to provide networking in the initrd.
+
 =============================================
 NetworkManager-1.52
 Overview of changes since NetworkManager-1.50

contrib/fedora/rpm/NetworkManager.spec

@@ -43,7 +43,7 @@
 
 %global real_version_major %(printf '%s' '%{real_version}' | sed -n 's/^\\([1-9][0-9]*\\.[0-9][0-9]*\\)\\.[0-9][0-9]*$/\\1/p')
 
-%global systemd_units NetworkManager.service NetworkManager-wait-online.service NetworkManager-dispatcher.service nm-priv-helper.service
+%global systemd_units NetworkManager.service NetworkManager-wait-online.service NetworkManager-dispatcher.service nm-priv-helper.service NetworkManager-config-initrd.service NetworkManager-initrd.service NetworkManager-wait-online-initrd.service
 
 %global systemd_units_cloud_setup nm-cloud-setup.service nm-cloud-setup.timer
 
@@ -829,7 +829,7 @@ if [ $1 -eq 0 ]; then
     # Don't kill networking entirely just on package remove
     #/bin/systemctl stop NetworkManager.service >/dev/null 2>&1 || :
 fi
-%systemd_preun NetworkManager-wait-online.service NetworkManager-dispatcher.service nm-priv-helper.service
+%systemd_preun NetworkManager-wait-online.service NetworkManager-dispatcher.service nm-priv-helper.service NetworkManager-config-initrd.service NetworkManager-initrd.service NetworkManager-wait-online-initrd.service
 
 
 %if %{with ifcfg_rh}
@@ -927,6 +927,9 @@ fi
 %{_unitdir}/NetworkManager-wait-online.service
 %{_unitdir}/NetworkManager-dispatcher.service
 %{_unitdir}/nm-priv-helper.service
+%{_unitdir}/NetworkManager-config-initrd.service
+%{_unitdir}/NetworkManager-initrd.service
+%{_unitdir}/NetworkManager-wait-online-initrd.service
 %dir %{_datadir}/doc/NetworkManager/examples
 %{_datadir}/doc/NetworkManager/examples/server.conf
 %if %{with ifcfg_warning} || %{with ifcfg_migrate}

data/NetworkManager-config-initrd.service.in

@@ -0,0 +1,27 @@
+[Unit]
+Description=NetworkManager Configuration (initrd)
+DefaultDependencies=no
+Wants=systemd-journald.socket
+After=systemd-journald.socket
+Before=systemd-udevd.service systemd-udev-trigger.service
+ConditionPathExists=/etc/initrd-release
+
+[Service]
+Type=oneshot
+ExecStartPre=/bin/sh -c "rm -f /run/NetworkManager/system-connections/*"
+ExecStart=/bin/sh -c "@libexecdir@/nm-initrd-generator -- $(cat /proc/cmdline)"
+ExecStartPost=/bin/sh -c ' \
+    for i in /{usr/lib,run,etc}/NetworkManager/system-connections/*; do \
+        [ -f "$i" ] || continue; \
+        mkdir -p /run/NetworkManager/initrd; \
+        : > /run/NetworkManager/initrd/neednet; \
+        break; \
+    done; \
+    if [ -s /run/NetworkManager/initrd/hostname ]; then \
+        cat /run/NetworkManager/initrd/hostname > /proc/sys/kernel/hostname; \
+    fi \
+'
+RemainAfterExit=yes
+
+[Install]
+WantedBy=initrd.target

data/NetworkManager-initrd.service.in

@@ -0,0 +1,32 @@
+[Unit]
+Description=NetworkManager (initrd)
+DefaultDependencies=no
+Wants=systemd-udev-trigger.service network.target
+After=systemd-udev-trigger.service network-pre.target dbus.service NetworkManager-config-initrd.service
+Before=network.target
+BindsTo=dbus.service
+ConditionPathExists=/etc/initrd-release
+ConditionPathExists=/run/NetworkManager/initrd/neednet
+ConditionPathExistsGlob=|/usr/lib/NetworkManager/system-connections/*
+ConditionPathExistsGlob=|/run/NetworkManager/system-connections/*
+ConditionPathExistsGlob=|/etc/NetworkManager/system-connections/*
+
+[Service]
+Type=dbus
+BusName=org.freedesktop.NetworkManager
+ExecReload=/usr/bin/busctl call org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.NetworkManager Reload u 0
+ExecStart=@sbindir@/NetworkManager
+# NM doesn't want systemd to kill its children for it
+KillMode=process
+Environment=NM_CONFIG_ENABLE_TAG=initrd
+Restart=on-failure
+ProtectSystem=true
+ProtectHome=read-only
+
+[Install]
+WantedBy=initrd.target
+# We want to enable NetworkManager-wait-online-initrd.service whenever this
+# service is enabled. NetworkManager-wait-online-initrd.service has
+# WantedBy=network-online.target, so enabling it only has an effect if
+# network-online.target itself is enabled or pulled in by some other unit.
+Also=NetworkManager-config-initrd.service NetworkManager-wait-online-initrd.service

data/NetworkManager-wait-online-initrd.service.in

@@ -0,0 +1,26 @@
+[Unit]
+Description=NetworkManager Wait Online (initrd)
+DefaultDependencies=no
+Requires=NetworkManager-initrd.service
+After=NetworkManager-initrd.service
+Before=network-online.target
+ConditionPathExists=/etc/initrd-release
+ConditionPathExists=/run/NetworkManager/initrd/neednet
+
+[Service]
+# `nm-online -s` waits until the point when NetworkManager logs
+# "startup complete". That is when startup actions are settled and
+# devices and profiles reached a conclusive activated or deactivated
+# state. It depends on which profiles are configured to autoconnect and
+# also depends on profile settings like ipv4.may-fail/ipv6.may-fail,
+# which affect when a profile is considered fully activated.
+# Check NetworkManager logs to find out why wait-online takes a certain
+# time.
+
+Type=oneshot
+ExecStart=@bindir@/nm-online -s -q
+RemainAfterExit=yes
+Environment=NM_ONLINE_TIMEOUT=3600
+
+[Install]
+WantedBy=initrd.target network-online.target

data/meson.build

@@ -13,6 +13,9 @@ if install_systemdunitdir
     'NetworkManager.service',
     'nm-priv-helper.service',
     'NetworkManager-wait-online.service',
+    'NetworkManager-config-initrd.service',
+    'NetworkManager-initrd.service',
+    'NetworkManager-wait-online-initrd.service',
   ]
 
   foreach service: services