cml2のubuntuでcloudinitを行う際にexabgpとfrrをインストールしておく例です。鍵はいい感じに好きなのに変えておいて使ってください

cml2exabgp.yaml

#cloud-config
hostname: exabgp1
manage_etc_hosts: True
timezone: Asia/Tokyo
system_info:
  default_user:
    name: cisco
password: cisco
chpasswd: { expire: False }
ssh_pwauth: True
ssh_authorized_keys:
    - "<your insert key>"
packages:
  - unzip
  - make
  - python3
  - python3-pip
write_files:
  - path: /root/install-exabgp.sh
    permissions: 0744
    owner: root
    content: |
      #!/usr/bin/env bash
      set -e
      apt-get update
      curl -sSL https://install.python-poetry.org | python3 -
      wget https://github.com/Exa-Networks/exabgp/archive/refs/heads/main.zip
      unzip main.zip
      pushd exabgp-main
      make build
      pip install --system ./dist/exabgp-5.0.0-py3-none-any.whl
      cat << EOF >/etc/systemd/system/exabgp.service
      [Unit]
      Description=ExaBGP
      Documentation=man:exabgp(1)
      Documentation=man:exabgp.conf(5)
      Documentation=https://github.com/Exa-Networks/exabgp/wiki
      After=network.target
      ConditionPathExists=/etc/exabgp/exabgp.conf

      [Service]
      User=exabgp
      Group=exabgp
      Environment=exabgp_daemon_daemonize=false
      RuntimeDirectory=exabgp
      RuntimeDirectoryMode=0750
      ExecStartPre=-/usr/bin/mkfifo /run/exabgp/exabgp.in
      ExecStartPre=-/usr/bin/mkfifo /run/exabgp/exabgp.out
      ExecStart=/usr/local/bin/exabgp /etc/exabgp/exabgp.conf
      ExecReload=/bin/kill -USR1 $MAINPID
      Restart=always
      CapabilityBoundingSet=CAP_NET_ADMIN CAP_NET_BIND_SERVICE
      AmbientCapabilities=CAP_NET_ADMIN CAP_NET_BIND_SERVICE

      [Install]
      WantedBy=multi-user.target
      EOF
      systemctl daemon-reload
      popd
      mkdir /etc/exabgp
      cat << EOF > /etc/exabgp/exabgp.conf
      neighbor 10.0.0.2 {
            router-id 10.0.0.1;
            local-address 10.0.0.1;
            local-as 65000;
            peer-as 65000;

            family {
                ipv4 mup;
                ipv6 mup;
            }
            announce {
                ipv4 {
                    mup \
                    mup-isd 10.0.1.0/24 rd 100:100 \
                    next-hop 2001::1 \
                    extended-community [ target:10:10 ] \
                    bgp-prefix-sid-srv6 ( l3-service 2001:db8:1:1:: 0x48 [64,24,16,0,0,0] );

                    mup \
                    mup-dsd 10.0.0.1 rd 100:100 \
                    next-hop 2001::2 \
                    extended-community [ target:10:10 mup:10:10 ] \
                    bgp-prefix-sid-srv6 ( l3-service 2001:db8:1:1:: 0x13 [64,24,16,0,0,0] );
                    
                    mup \
                    mup-t1st 192.168.0.1/32 rd 100:100 teid 12345 qfi 9 endpoint 10.0.0.1 \
                    next-hop 10.0.0.2 \
                    extended-community [ target:10:10 ];

                    mup \
                    mup-t2st 10.0.0.1 rd 100:100 teid 12345/32 \
                    next-hop 10.0.0.2 \
                    extended-community [ target:10:10 mup:10:10 ];
                }
                ipv6 {
                    mup \
                    mup-isd 2001::/64 rd 100:100 \
                    next-hop 2001::2 \
                    extended-community [ target:10:10 ] \
                    bgp-prefix-sid-srv6 ( l3-service 2001:db8:1:1:: 0x47 [64,24,16,0,0,0] );

                    mup \
                    mup-dsd 2001::1 rd 100:100 \
                    next-hop 2001::2 \
                    extended-community [ target:10:10 mup:10:10 ] \
                    bgp-prefix-sid-srv6 ( l3-service 2001:db8:2:2:: 0x18 [64,24,16,0,0,0] );
                    
                    mup \
                    mup-t1st 2001:db8:1:1::1/128 rd 100:100 teid 12345 qfi 9 endpoint 2001::1\
                    next-hop 10.0.0.2 \
                    extended-community [ target:10:10 ];

                    mup \
                    mup-t2st 2001::1 rd 100:100 teid 12345/32 \
                    next-hop 10.0.0.2 \
                    extended-community [ target:10:10 mup:10:10 ];
                }
            }
      }
      EOF
      groupadd --system exabgp
      useradd --system -d /var/lib/exabgp -s /bin/bash -g exabgp exabgp
      systemctl enable exabgp
      systemctl start exabgp
        
  - path: /etc/netplan/50-cloud-init.yaml
    content: |
      network:
        ethernets:
          ens2:
            dhcp4: true
          ens3:
            dhcp4: false
          ens4:
            dhcp4: false
        version: 2
  - path: /root/install-frr.sh
    permissions: 0744
    owner: root
    content: |
      curl -s https://deb.frrouting.org/frr/keys.asc | apt-key add -
      echo deb https://deb.frrouting.org/frr $(lsb_release -s -c) frr-stable | tee -a /etc/apt/sources.list.d/frr.list
      apt-get update && apt-get install -y frr frr-pythontools
     
runcmd:
  - sudo netplan apply
  - sudo bash /root/install-exabgp.sh
  - sudo bash /root/install-frr.sh

これが正常動作してるかはこんな感じの雰囲気で確認できる。

cisco@exabgp1:~$ sudo exabgp-cli show adj-rib out
command: show adj-rib out
neighbor 10.0.0.2 ipv4 mup mup:isd::100:100:10.0.1.0/24
neighbor 10.0.0.2 ipv4 mup mup:dsd::100:100:10.0.0.1
neighbor 10.0.0.2 ipv4 mup mup:t1st::100:100:192.168.0.1/32:12345:9:32:10.0.0.1
neighbor 10.0.0.2 ipv4 mup mup:t2st::100:100:12345:32:10.0.0.1
neighbor 10.0.0.2 ipv6 mup mup:isd::100:100:2001::/64
neighbor 10.0.0.2 ipv6 mup mup:dsd::100:100:2001::1
neighbor 10.0.0.2 ipv6 mup mup:t1st::100:100:2001:db8:1:1::1/128:12345:9:128:2001::1
neighbor 10.0.0.2 ipv6 mup mup:t2st::100:100:12345:128:2001::1

コンフィグを書き換えるときはvim /etc/exabgp/exabgp.conf でよしなにする感じ。その後は sudo exabgp-cli reloadとかで更新ができるはず