[RFC 00/13] reuse NetworkManager connection profiles to set up kdump network

[Coiby Xu]

Currently, kexec-tools parses legacy ifcfg-* configuration files or
NetworkManager .nmconnection connection profiles to build up dracut
command line parameters like ip=. Then dracut parses these parameters and
runs nm-initrd-generator to generate NetworkManager connection profiles.
Taking a bonding network as an example, nm-initrd-generator generates two
connections as follows,
  $ /usr/libexec/nm-initrd-generator -s -- bootdev=mybond0 rd.neednet kdumpnic=mybond0
bond=mybond0:kdump-eth0
  
  *** Connection 'mybond0' ***
  
  [connection]
  id=mybond0
  uuid=ed87d02b-dd44-4f0e-8b11-37db7e89bb48
  type=bond
  autoconnect-retries=1
  interface-name=mybond0
  multi-connect=1
  permissions=
  
  [bond]
  mode=balance-rr
  
  [ipv4]
  dhcp-timeout=90
  dns-search=
  method=auto
  
  [ipv6]
  addr-gen-mode=eui64
  dhcp-timeout=90
  dns-search=
  method=auto
  
  [proxy]
  
  *** Connection 'kdump-eth0' ***
  
  [connection]
  id=kdump-eth0
  uuid=ed6a7448-b5f8-4f8a-b718-3e24ea1c924b
  type=ethernet
  autoconnect-retries=1
  interface-name=kdump-eth0
  master=ed87d02b-dd44-4f0e-8b11-37db7e89bb48
  multi-connect=1
  permissions=
  slave-type=bond
  wait-device-timeout=60000
  
  [ethernet]
  mac-address-blacklist=

Later dracut starts NetworkManager to activate these profiles to bring up
the network connections. This way of seting up kdump network is tedious,
error-prone and unncessary. A better way is to directly copy the needed
connection profiles to initrd. A potential benefit of this approach for
the users is they can simply edit the connection profile directly like
changing ipv4.dhcp-timeout instead of being forced to use the hard-coded
value enforced by nm-initrd-generator.

This patch set reuses NetworkManager connection profiles to set up kdump
network. It also reduces the memory consumption of network drivers and
fix other issues at the same time. Here are the bug list that addressed by
this patch set on bugzilla,
  - Bug 1962421 - [RHEL-9]"eth0: Failed to rename network interface 3 from
'eth0' to 'kdump-eth0': File exists"
  - Bug 2064708 - kdump: mkdumprd: failed to make kdump initrd for bridge network on z15
z/vm
		- bugs related to OOM caused by network driver
		  - Bug 1950282 - shutdown those unneeded network interfaces to save memory for kdump
		  - Bug 1958587 - the kdump initramfs includes unnecessary NIC drivers for SSH/NFS
dumping target
		  - Bug 1890021 - be2net is using too much memory during kdump
		  - Bug 1662202 - [RHEL-8.1] aarch64: hpe-apache crashkernel OOM when dump to network
targe

Coiby Xu (13):
  add function to copy NetworkManage connection profile to the initramfs
  support legacy ifcfg
  ask NM to wait the network device to be available
  don't let NetworkManager manage unneeded network interfaces
  stop dracut 35network-manager from running nm-initrd-generator
  set up kdump network bridge by directly copying NM connection profile
    to initrd
  set up kdump bonding network by directly copying NM connection profile
    to initrd
  fix error for vlan over team network interface
  set up kdump vlan network by directly copying NM connection profile to
    initrd
  set up kdump teaming network by directly copying NM connection profile
    to initrd
  clean up unneeded code after copying .nmconnection to initrd
  address the cases where a NIC has a different name in kdump kernel
  simplify setup_znet by copying connection profile to initrd

 dracut-kdump.sh        |  18 +-
 dracut-module-setup.sh | 385 ++++++++++++++---------------------------
 2 files changed, 133 insertions(+), 270 deletions(-)

-- 
2.34.1