Linux: add lag support and bonding plugin for non-lag cases

docs/caveats.md

@@ -280,6 +280,10 @@ We're not testing Fortinet implementation as part of the regular integration tes
 * Junos cannot have more than one loopback interface per routing instance. Using **loopback** links on Junos devices will result in configuration errors.
 * Junos configuration template configures BFD timers within routing protocol configuration, not on individual interfaces
 
+(caveats-linux)=
+## Generic Linux lag module caveats
+* The lag module requires the `ip` command to be available on the Linux host
+
 (caveats-vptx)=
 ## Juniper vPTX
 

docs/module/lag.md

@@ -13,6 +13,7 @@ LAG is currently supported on these platforms:
 | Cumulus 5.x (NVUE)    | ✅ | ✅ | ❌  | ❌ |
 | Dell OS10             | ✅ | ✅ | ✅ | ✅ |
 | FRR                   | ✅ | ✅ | ❌  | ❌ |
+| Generic Linux hosts [❗](caveats-linux)  | ✅ | ✅ | ❌  | ❌ |
 
 ## Parameters
 
@@ -31,7 +32,7 @@ The following parameters can be set on individual links:
 
 * **lag.members**: Mandatory list of links that form the LAG. It uses the [same format as the topology **links** list](link-formats).
 * **lag.ifindex**: Optional parameter that controls the naming of the LAG (bonding, port-channel) interface.
-* **lag.mlag**: Optional Boolean or dict with peer link parameters; see [below](mlag)
+* **lag.mlag**: Optional dict with peer link parameters; see [below](mlag)
 
 This configuration module creates a virtual link with the link type set to **lag** between the **lag.members** and appends the links described in the **lag.members** list to the topology **links** list.
 

docs/plugins.md

@@ -9,6 +9,7 @@
    plugins/bgp.domain.md
    plugins/bgp.session.md
    plugins/bgp.policy.md
+   plugins/bonding.md
    plugins/ebgp.multihop.md
    plugins/bgp.originate.md
    plugins/check.config.md

docs/plugins/bonding.md

@@ -0,0 +1,66 @@
+(plugin-bonding)=
+# Host-side link bonding
+
+Linux networking has long supported *bonding*, the ability to use multiple links simultaneously. Netlab supports bonding with LACP through the *lag* module,
+this plugin adds support for the other bonding modes (that don't require any special configuration on peers)
+
+```eval_rst
+.. contents:: Table of Contents
+   :depth: 2
+   :local:
+   :backlinks: none
+```
+
+## Using the Plugin
+
+* Add `plugin: [ bonding ]` to the lab topology.
+* Include the **bonding.ifindex** attribute in any links that need to be bonded
+
+### Supported attributes
+
+The plugin adds the following attributes:
+* **bonding.mode** (string, one of active-backup, balance-tlb, or balance-alb) -- the bonding mode to use, default `active-backup`
+
+Additional interface level attributes:
+* **bonding.ifindex** (int,mandatory) -- the interface index for the bonding device; links with matching ifindex are bonded together
+* **bonding.primary** (bool) -- optional flag to mark this interface as primary, default *False*
+
+## Examples
+
+(active-backup-bonding)=
+### Connect a host to a pair of switches using active-backup bonding
+
+```yaml
+plugin: [ bonding ]
+
+bonding.mode: active-backup  # Default
+
+vlans:
+  v1:
+
+groups:
+  _auto_create: True
+  hosts:
+    members: [ h1 ]
+    device: linux
+  switches:
+    members: [ s1, s2 ]
+    module: [ vlan ]
+
+links:
+- s1:
+  s2:
+  vlan.trunk: [ v1 ]
+
+# Bonded interfaces eth1/eth2
+- s1:
+  h1:
+    bonding.ifindex: 1
+- s2:
+  h1:
+    bonding:
+      ifindex: 1
+      primary: True  # Use this interface as primary
+```
+
+Note how there are no bonding specific modules enabled on the switches

netsim/ansible/templates/initial/linux/ubuntu.j2

@@ -64,10 +64,21 @@ if systemctl is-active --quiet lldpd.service; then
 else
   if "$NEED_APT_UPDATE"; then
     apt-get update -qq
+    NEED_APT_UPDATE=
   fi
   apt-get install -qq lldpd
 fi
 
+{% if 'lag' in module|default([]) %}
+#
+# Install ethtool and iproute2(ip) for lag support
+#
+if "$NEED_APT_UPDATE"; then
+    apt-get update -qq
+fi
+apt-get install -qq ethtool iproute2
+{% endif %}
+
 cat <<CONFIG >/etc/lldpd.d/system.conf
 configure lldp tx-interval 30
 configure lldp tx-hold 3

netsim/ansible/templates/initial/linux/vanilla.j2

@@ -1,3 +1,5 @@
+{% from "lag/linux.j2" import create_bond_dev with context %}
+
 ### One-Shot configuration (non-Ubuntu VM or container)
 #
 # Disable IPv4 and IPv6 forwarding
@@ -24,9 +26,12 @@ ip -6 addr add {{ loopback.ipv6 }} dev lo
 {%   endif %}
 {% endif %}
 #
-# Interface addressing
+# Interface addressing, create any bond devices
 #
 {% for l in interfaces|default([]) %}
+{%   if l.type in ['lag','bond'] %}
+{{     create_bond_dev(l) }}
+{%   endif %}
 ip link set dev {{ l.ifname }} up
 {% if l.ipv4 is defined %}
 set +e
@@ -41,7 +46,7 @@ ip -6 addr del {{ l.ipv6 }} dev {{ l.ifname }} 2>/dev/null
 set -e
 ip -6 addr add {{ l.ipv6 }} dev {{ l.ifname }}
 {% endif %}
-{% if l.mtu is defined %}
+{% if l.mtu is defined and l.type!='lag' %}
 ip link set {{ l.ifname }} mtu {{ l.mtu }}
 {% endif %}
 {% endfor %}

netsim/ansible/templates/lag/frr.j2

@@ -1,42 +1 @@
-#!/bin/bash
-#
-set -e # Exit immediately when any command fails
-#
-{% if node_provider != 'clab' %}
-modprobe bonding miimon=100 mode=802.3ad lacp_rate=fast
-{% endif %}
-#
-# Create bonds for LAGs, if any. Requires kernel bonding module loaded
-#
-{% for l in interfaces if 'lag' in l %}
-{%  if l.type=='lag' %}
-{%   set _m = l.lag.mode|default(lag.mode) %}
-{%   if _m=="802.3ad" %}
-{%     set _lacp = l.lag.lacp|default(lag.lacp) %}
-{%     set lacp_act = 'off' if _lacp=='off' else 'on' %}
-{%     set lacp_rate = (' lacp_rate ' + _lacp) if _lacp!='off' else '' %}
-{%     set _m = _m + " xmit_hash_policy encap3+4" + lacp_rate %}
-{%     if node_provider == 'clab' %}
-{%       set _m = _m + " lacp_active " + lacp_act %}
-{%     endif %}
-{%   endif %}
-ip link add dev {{l.ifname}} type bond mode {{_m}}
-{%  endif %}
-ip link set dev {{ l.ifname }} down
-{% endfor %}
-
-{% for l in interfaces if 'lag' in l and l.type != 'lag' %}
-{%   if l.type=='p2p' %}
-{%     if node_provider != 'clab' %}
-ethtool -s {{ l.ifname }} autoneg off speed 1000 duplex full
-{%     endif %}
-ip link set dev {{ l.ifname }} master {% 
-       for i in interfaces if i.type=='lag' and i.linkindex==l.lag._parentindex %}{{ i.ifname }}
-{%     endfor %}
-{%   endif %}
-ip link set dev {{ l.ifname }} up
-{% endfor %}
-{% for l in interfaces if 'lag' in l and l.type == 'lag' %}
-ip link set dev {{ l.ifname }} up
-{% endfor %}
-exit 0
+{% include "linux.j2" %}

netsim/ansible/templates/lag/linux.j2

@@ -0,0 +1,52 @@
+{% macro create_bond_dev(l) %}
+{%   if l.type in ['lag','bond'] %}
+{%     set _m = l.lag.mode|default(l.bonding.mode|default("802.3ad")) %}
+{%     if _m=="802.3ad" %}
+{%       set _lacp = l.lag.lacp|default('fast') %}
+{%       set lacp_act = 'off' if _lacp=='off' else 'on' %}
+{%       set lacp_rate = (' lacp_rate ' + _lacp) if _lacp!='off' else '' %}
+{%       set _m = _m + lacp_rate %}
+{%       if node_provider == 'clab' %}
+{%         set _m = _m + " lacp_active " + lacp_act %}
+{%       endif %}
+{%     elif l.bonding.primary is defined %}
+{%       set _m = _m + " primary " + l.bonding.primary %}
+{%     endif %}
+{%     if _m in ["802.3ad","balance-xor","balance-alb","balance-tlb"] %}
+{%       set _m = _m + " xmit_hash_policy encap3+4" %}
+{%     endif %}
+{%     if node_provider != 'clab' %}
+#
+# Make sure 'bonding' module is loaded
+#
+if [ ! -e /sys/module/bonding ]; then
+modprobe bonding miimon=100 mode=802.3ad lacp_rate=fast
+fi
+{%     endif %}
+if [ ! -e /sys/class/net/{{l.ifname}} ]; then
+ip link add dev {{l.ifname}} type bond mode {{ _m }}
+fi
+{%   endif %}
+{% endmacro -%}
+#!/bin/bash
+#
+set -e # Exit immediately when any command fails
+#
+# Bond devices are created by 'initial' module - add members
+#
+{% for l in interfaces if 'lag' in l and l.type != 'lag' %}
+{%   if l.type=='p2p' %}
+{%     if node_provider != 'clab' %}
+ethtool -s {{ l.ifname }} autoneg off speed 1000 duplex full
+{%     endif %}
+ip link set dev {{ l.ifname }} down
+ip link set dev {{ l.ifname }} master {%
+       for i in interfaces if i.type=='lag' and i.linkindex==l.lag._parentindex %}{{ i.ifname }}
+{%     endfor %}
+{%   endif %}
+ip link set dev {{ l.ifname }} up
+{% endfor %}
+{% for l in interfaces if 'lag' in l and l.type == 'lag' %}
+ip link set dev {{ l.ifname }} up
+{% endfor %}
+exit 0

netsim/augment/links.py

@@ -1168,7 +1168,8 @@ def transform(link_list: typing.Optional[Box], defaults: Box, nodes: Box, pools:
       continue
 
     set_link_bridge_name(link,defaults)
-    link_default_pools = ['p2p','lan'] if link.type in ['p2p','lag'] else ['lan']
+    link_default_pools = ['p2p','lan'] if link.type=='p2p' or (
+                                          link.type=='lag' and not 'vlan' in link) else ['lan']
     assign_link_prefix(link,link_default_pools,pools,nodes,link._linkname)
     copy_link_gateway(link,nodes)
     assign_interface_addresses(link,pools,nodes,defaults)

netsim/devices/linux.yml

@@ -1,5 +1,6 @@
 description: Generic Linux host
 interface_name: eth{ifindex}
+lag_interface_name: "bond{lag.ifindex}"
 mgmt_if: eth0
 role: host
 features:
@@ -9,6 +10,8 @@ features:
       ipv6: true
     server: true
     relay: true
+  lag:
+    passive: False
 libvirt:
   image: generic/ubuntu2004
   group_vars:

netsim/extra/bonding/defaults.yml

@@ -0,0 +1,25 @@
+# bonding plugin attributes
+#
+---
+bonding:
+  mode: active-backup  # Default bond mode
+
+devices:
+  linux:
+    features.bonding: True
+  frr:
+    features.bonding: True
+
+attributes:
+  global:
+    bonding:
+      # Subset of Linux bonding modes that use autonomous ports and no LACP
+      mode: { type: str, valid_values: [ active-backup, balance-tlb, balance-alb ] }
+  node:
+    bonding:
+      mode:
+  interface:
+    bonding:
+      ifindex: { type: int, min_value: 0, _required: True }
+      mode: { copy: global }
+      primary: bool # Optional flag to use this interface as primary for bonding

netsim/extra/bonding/frr.j2

@@ -0,0 +1 @@
+{% include linux.j2 %}

netsim/extra/bonding/linux.j2

@@ -0,0 +1,23 @@
+{% from "templates/lag/linux.j2" import create_bond_dev with context %}
+#!/bin/bash
+
+set -e
+
+# Check if the 'ip' command is available, if not install it
+if ! command -v ip 2>&1 >/dev/null
+then
+  echo "Trying to install the 'ip' and 'ethtool' commands..."
+  apt-get -qq update
+  apt-get -qq install ethtool iproute2
+fi
+
+{# Bonding device is created by 'initial' module #}
+{% for intf in interfaces|default([]) if intf.bonding.members is defined %}
+ip link set dev {{ intf.ifname }} down
+{%   for member in intf.bonding.members %}
+ip link set dev {{ member }} down
+ip link set dev {{ member }} master {{ intf.ifname }}
+ip link set dev {{ member }} up
+{%   endfor %}
+ip link set dev {{ intf.ifname }} up
+{% endfor %}