VM 对使用 ansible shell 任务执行的 virsh 命令不可见

Question

I am trying to save the state of all running VM's before I can shut down the host.

virsh save <domain-name> <filetosave>

The idea is to restore the VM's when I bring back the host again.

I am using ansible virt module to determine the running VM's. There is no command available for saving the virtual machine using virt module hence using shell module like below

 tasks:

  - name: Gathering Facts
    setup:

  # Listing VMs
  - name: list all VMs
    virt:
      command: list_vms
    register: all_vms

  - name: list only running VMs
    virt:
      command: list_vms
      state: running
    register: running_vms

  - name: Print All VM'state
    debug:
      msg: |
        VM's: {{ all_vms.list_vms }},
        Active VM's: {{ running_vms.list_vms }}

  - name: Save Running VM's
    shell: >
      virsh save {{ item }} ~/.mykvm/{{item}}.save
    args:
      chdir: /home/sharu
      executable: /bin/bash
    loop:
      "{{ running_vms.list_vms }}"
    register: save_result
  - debug:
      var: save_result

Output:

TASK [list all VMs] 
*********
ok: [192.168.0.113]

TASK [list only running VMs] 
*********
ok: [192.168.0.113]

TASK [Print All VM'state] 
*********
ok: [192.168.0.113] => {
    "msg": "VM's: [u'win10-2', u'ubuntu18.04', u'ubuntu18.04-2', u'win10'],\nActive VM's: [u'win10-2']\n"
}

TASK [Save Running VM's] 
*********
failed: [192.168.0.113] (item=win10-2) => {"ansible_loop_var": "item", "changed": true, "cmd": "virsh save win10-2 ~/.mykvm/win10-2.save\n", "delta": "0:00:00.101916", "end": "2019-12-30 01:19:32.205584", "item": "win10-2", "msg": "non-zero return code", "rc": 1, "start": "2019-12-30 01:19:32.103668", "stderr": "error: failed to get domain 'win10-2'", "stderr_lines": ["error: failed to get domain 'win10-2'"], "stdout": "", "stdout_lines": []}

PLAY RECAP 
******************
192.168.0.113              : ok=5    changed=0    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0

Notice the virt module was able to get the information regarding the running domain's(VM's) but the shell command failed to get the domain name. It seems like the VM's are not visible for Ansible's shell task

To debug further I executed the Ansible ad-hoc command below but got the blank result

$ ansible -i ../hosts.ini RIG3600 -m shell -a "virsh list --all"
192.168.0.113 | CHANGED | rc=0 >>
 Id   Name   State
--------------------

The same command works fine in the Linux shell

$ virsh list --all

 Id   Name            State
--------------------------------
 3    win10-2         running
 -    ubuntu18.04     shut off
 -    ubuntu18.04-2   shut off
 -    win10           shut off

Am using Ansible version 2.8.3 Not sure am I missing something here, any help is much appreciated.

Answer 1

The virt module, as documented , defaults to using the libvirt URI qemu:///system .

The virsh command, on the other hand, when run as a non-root user, defaults to qemu:///session .

In other words, your virsh command is not talking to the same libvirt instance as your virt tasks.

You can provide an explicit URI to the virsh command using the -c ( --connect ) option:

virsh -c qemu:///system ...

Or by setting the LIBVIRT_DEFAULT_URI environment variable:

  - name: Save Running VM's
    shell: >
      virsh save {{ item }} ~/.mykvm/{{item}}.save
    args:
      chdir: /home/sharu
      executable: /bin/bash
    environment:
      LIBVIRT_DEFAULT_URI: qemu:///system
    loop:
      "{{ running_vms.list_vms }}"
    register: save_result

(You can also set environment on the play instead of on an individual task).