Using ansible to modify ip address on system

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1

Okay, we’ve ran out of ip addresses, and got a larger subnet from our ip. I am currently in the process of switching them over, and decided it would be nice to do this with ansible, but I have ran into a little snag.

Currently I have:

  • shell: “ifconfig | grep -B1 {{ old_address }}| grep -E ‘^(\w+)[[:space:]]’ | sed ‘s/\s.*$//’”
    args:
    executable: /bin/bash
    register: network_interface

  • template:
    src: files/linux_network_interfaces.j2
    dest: /etc/network/interfaces
    owner: root
    group: root
    mode: ‘0644’
    become: true
    when: item.key == inventory_hostname
    with_dict: “{{ new_addresses }}”

  • shell: “ifdown {{ network_interface.stdout }} && ifup {{ network_interface.stdout }}”
    args:
    executable: /bin/bash
    become: true

But it hangs in the last shell task… since the IP address was changed.

Is there a way I can tell this task to just run, then use set_fact to modify each host to its new IP to ping and make sure it worked, then I’ll move forward and modify our DNS records to match the new hosts…

2

Solved it via running the command as “fire and forget” with async and pool, using a bash command in the background. Then modifying the ansible_ssh_host to the new IP address, and waiting for it port 22 to come up on that host.

  • name: Grab the network interface that the old IP is using and store it.
    shell: “ifconfig | grep -B1 {{ old_address_start }}| grep -E ‘^(\w+)[[:space:]]’ | sed ‘s/\s.*$//’”
    args:
    executable: /bin/bash
    register: network_interface

  • name: Pushout new /etc/network/interface to hosts
    template:
    src: files/linux_network_interfaces.j2
    dest: /etc/network/interfaces
    owner: root
    group: root
    mode: ‘0644’
    become: true
    when: item.key == inventory_hostname
    with_dict: “{{ new_addresses }}”

  • name: Reload the hosts’ network interface
    shell: “(sleep 1; ifdown {{ network_interface.stdout }} && ifup {{ network_interface.stdout }}) &”
    args:
    executable: /bin/bash
    become: true
    async: 100
    poll: 0

  • name: Change ansible’s ip address for each host
    set_fact:
    ansible_ssh_host: “{{ item.value.address }}”
    when: item.key == inventory_hostname
    with_dict: “{{ new_addresses }}”

  • name: Wait for the hosts’ network interface to come back up
    local_action:
    module: wait_for
    host: “{{ ansible_ssh_host }}”
    port: 22
    delay: 10
    state: started
    register: wait_result

  • name: Modify all of the route53 records for ip changes that succeeded
    local_action:
    module: route53
    command: create
    zone: xxxxx
    record: “{{ item.key }}”
    type: A
    value: “{{ item.value.address }}”
    overwrite: true
    when: item.key == inventory_hostname and wait_result|succeeded
    with_dict: “{{ new_addresses }}”

3

Hi, I was wondering if you could provide us with the j2 template for your network interface? If not, what are the basics that you used for it?

Thank you!