Nftables support

[kabakaev]

As of now, the nftables backend is not implemented.

Hence, it is not possible to run netavark on a Linux kernel with nftables modules and without iptables.

Altough the CONFIG_NFT_MASQ kernel config is enabled, the /usr/sbin/iptables-nft alternative iptables CLI cannot emulate the masquerade action and complains:

Error: netavark: unable to append rule '! -d 224.0.0.0/4 -j MASQUERADE' to table 'nat': code: 4, msg: Warning: Extension MASQUERADE revision 0 not supported, missing kernel module?
iptables v1.8.9 (nf_tables):  RULE_APPEND failed (No such file or directory): rule in chain NETAVARK-1700E948C4CCE

Supposedly, native nftables driver should fix the issue.

[Luap99]

iptables-nft should work, to my understanding distros like RHEL do not even ship the legacy iptables command and I know netavark works on RHEL. So I suggest you take a look at their kernel config.

I also tested iptables-nft on fedora before and it seems to work there as well.

But yes a proper nftables driver is on our TODO list, it just hasn't gotten enough prioritization so far.

[kabakaev]

Indeed, it works fine on a normal kernel in any distro. I'm referring to my case of an embedded system with pure nftables compiled in kernel, without CONFIG_NFT_COMPAT module for iptables/xt_tables compatibility.

[Luap99]

Yes I guess it is not possible at the moment then. Would you be interested in contributing this feature?

[imp1sh]

I would love this feature as well. As a DevOps engineer it becomes a bit annoying when you have a standard deployed e.g. with Ansible and then again you get pulled back into reality when you get reminded that it won't work with podman hosts...

[g00g1]

Hello,

I am having the same issue, however it should not happen to me as I have the latest podman and netavark versions. Please help me with troubleshooting, thanks!

Details

Error: netavark: unable to append rule '! -d 224.0.0.0/4 -j MASQUERADE' to table 'nat': code: 4, msg: Warning: Extension MASQUERADE revision 0 not supported, missing kernel module?
iptables v1.8.9 (nf_tables):  RULE_APPEND failed (No such file or directory): rule in chain NETAVARK-1D8721804F16F

admin@fedora:~$ sudo podman info --debug
host:
  arch: amd64
  buildahVersion: 1.33.2-dev
  cgroupControllers:
  - cpuset
  - cpu
  - io
  - memory
  - hugetlb
  - pids
  - rdma
  - misc
  cgroupManager: systemd
  cgroupVersion: v2
  conmon:
    package: conmon-2.1.8-2.fc39.x86_64
    path: /usr/bin/conmon
    version: 'conmon version 2.1.8, commit: '
  cpuUtilization:
    idlePercent: 94.38
    systemPercent: 3.17
    userPercent: 2.45
  cpus: 1
  databaseBackend: sqlite
  distribution:
    distribution: fedora
    version: "39"
  eventLogger: journald
  freeLocks: 2045
  hostname: fedora
  idMappings:
    gidmap: null
    uidmap: null
  kernel: 6.6.13-200.fc39.x86_64
  linkmode: dynamic
  logDriver: journald
  memFree: 970092544
  memTotal: 1493110784
  networkBackend: netavark
  networkBackendInfo:
    backend: netavark
    dns:
      package: aardvark-dns-1.9.0-1.20240124201435179069.main.26.g2fddbdf.fc39.x86_64
      path: /usr/libexec/podman/aardvark-dns
      version: aardvark-dns 1.11.0-dev
    package: netavark-1.10.1-1.20240126120738774699.main.4.gca3cf7a.fc39.x86_64
    path: /usr/libexec/podman/netavark
    version: netavark 1.11.0-dev
  ociRuntime:
    name: crun
    package: crun-1.14-1.20240124163144650285.main.1.g6507628.fc39.x86_64
    path: /usr/bin/crun
    version: |-
      crun version UNKNOWN
      commit: ef91050a09bb69cfaea8084e92969b18e84db0a8
      rundir: /run/crun
      spec: 1.0.0
      +SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +CRIU +LIBKRUN +WASM:wasmedge +YAJL
  os: linux
  pasta:
    executable: /usr/bin/pasta
    package: passt-0^20231230.gf091893-1.fc39.x86_64
    version: |
      pasta 0^20231230.gf091893-1.fc39.x86_64
      Copyright Red Hat
      GNU General Public License, version 2 or later
        <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
      This is free software: you are free to change and redistribute it.
      There is NO WARRANTY, to the extent permitted by law.
  remoteSocket:
    exists: true
    path: /run/podman/podman.sock
  security:
    apparmorEnabled: false
    capabilities: CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_FOWNER,CAP_FSETID,CAP_KILL,CAP_NET_BIND_SERVICE,CAP_SETFCAP,CAP_SETGID,CAP_SETPCAP,CAP_SETUID,CAP_SYS_CHROOT
    rootless: false
    seccompEnabled: true
    seccompProfilePath: /usr/share/containers/seccomp.json
    selinuxEnabled: true
  serviceIsRemote: false
  slirp4netns:
    executable: /usr/bin/slirp4netns
    package: slirp4netns-1.2.2-1.fc39.x86_64
    version: |-
      slirp4netns version 1.2.2
      commit: 0ee2d87523e906518d34a6b423271e4826f71faf
      libslirp: 4.7.0
      SLIRP_CONFIG_VERSION_MAX: 4
      libseccomp: 2.5.3
  swapFree: 1492119552
  swapTotal: 1492119552
  uptime: 0h 3m 29.00s
  variant: ""
plugins:
  authorization: null
  log:
  - k8s-file
  - none
  - passthrough
  - journald
  network:
  - bridge
  - macvlan
  - ipvlan
  volume:
  - local
registries:
  search:
  - registry.fedoraproject.org
  - registry.access.redhat.com
  - docker.io
  - quay.io
store:
  configFile: /usr/share/containers/storage.conf
  containerStore:
    number: 3
    paused: 0
    running: 0
    stopped: 3
  graphDriverName: overlay
  graphOptions:
    overlay.mountopt: nodev,metacopy=on
  graphRoot: /var/lib/containers/storage
  graphRootAllocated: 41872785408
  graphRootUsed: 1915011072
  graphStatus:
    Backing Filesystem: btrfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Supports shifting: "true"
    Supports volatile: "true"
    Using metacopy: "true"
  imageCopyTmpDir: /var/tmp
  imageStore:
    number: 1
  runRoot: /run/containers/storage
  transientStore: false
  volumePath: /var/lib/containers/storage/volumes
version:
  APIVersion: 5.0.0-dev-4bef65240
  Built: 1706293970
  BuiltTime: Fri Jan 26 18:32:50 2024
  GitCommit: ""
  GoVersion: go1.21.6
  Os: linux
  OsArch: linux/amd64
  Version: 5.0.0-dev-4bef65240

UPD: adding NETAVARK_FW=nftables to the /etc/environment solves this issue.

[mheon]

You can set firewall driver from containers.conf via the firewall_driver option; see https://github.com/containers/common/blob/main/pkg/config/containers.conf#L355

[g00g1]

@mheon, thanks for this tip! Although, this option was not present in mine configuration for some reason, considering that I have done clean installation.