Ansible provisionner try to connect to localhost

[RemiDesgrange]

Overview of the Issue

When I specify a an ansible provisionner :

build {
  name = "test_template"
  sources = [
    "sources.proxmox-iso.debian-tmpl",
  ]
  provisioner "ansible" {
    playbook_file = "playbooks/debian-tmpl.yml"
    user = "reachable_user"
  }
}

The process work great until the ansible part where ansible try to connect to localhost instead of the server. The server gets it's address and has the qemu-guest-agent active, I can see the IP in the proxmox webUI.

Reproduction Steps

• Create a minimal packer build with an ansible playbook
• Run it.

Plugin and Packer version

Packer 1.7.4

Simplified Packer Buildfile

build {
  name = "debian_template"
  sources = [
    "sources.proxmox-iso.debian-template",
  ]
  provisioner "ansible" {
    playbook_file = "playbooks/debian-template.yml"
    user = "reachable_user"
  }
}

Source:

source "proxmox-iso" "debian-template" {
  proxmox_url              = "${var.proxmox_hostname}/api2/json"
  insecure_skip_tls_verify = false
  username                 = var.proxmox_username
  password                 = var.proxmox_password
  node                     = var.proxmox_node_name

  vm_name              = "debian-11-packer-${var.template_name}"
  template_name        = "debian-11-template-${var.template_name}"
  template_description = "Template ready to be terraformed."

  memory = 4096
  cores  = 8
  os     = "l26"

  network_adapters {
    model  = "virtio"
    bridge = "vmbr1"
  }
  qemu_agent              = true
  cloud_init              = true
  cloud_init_storage_pool = "local-lvm"
  scsi_controller         = "virtio-scsi-single"
  disks {
    type              = "virtio"
    io_thread         = true
    disk_size         = 8
    storage_pool      = "local-lvm"
    storage_pool_type = "lvm"
    format            = "raw"
  }

  iso_file         = var.iso_file
  iso_storage_pool = "local-lvm"
  iso_checksum     = var.iso_checksum

  ssh_username = var.ssh_username
  ssh_password = var.ssh_password
  ssh_timeout  = "30m"
  boot_wait    = "4s"
  unmount_iso  = true
  boot_command = [
    "<esc><wait>",
    "auto ",
    "url=${var.user_data_server}preseed.cfg ",
    "<enter><wait>"
  ]

  http_directory = "http"
}

Operating system and Environment details

Arch linux for the client

Log Fragments and crash.log files

==> debian_template.proxmox-iso.debian-practice: Connected to SSH!
==> debian_template.proxmox-iso.debian-practice: Provisioning with Ansible...
    debian_template.proxmox-iso.debian-practice: Setting up proxy adapter for Ansible....
==> debian_template.proxmox-iso.debian-practice: Executing Ansible: ansible-playbook -e packer_build_name="debian-template" -e packer_builder_type=proxmox-iso -e packer_http_addr=192.168.1.100:8873 --ssh-extra-args '-o IdentitiesOnly=yes' -e ansible_ssh_private_key_file=/tmp/ansible-key589778536 -i /tmp/packer-provisioner-ansible3468307636 /home/remi/Documents/packer/playbooks/debian-templaye.yml
    student_debian_template.proxmox-iso.debian-practice:  ______________________
    student_debian_template.proxmox-iso.debian-practice: < PLAY [Minimum setup] >
    student_debian_template.proxmox-iso.debian-practice:  ----------------------
    student_debian_template.proxmox-iso.debian-practice:         \   ^__^
    student_debian_template.proxmox-iso.debian-practice:          \  (oo)\_______
    student_debian_template.proxmox-iso.debian-practice:             (__)\       )\/\
    student_debian_template.proxmox-iso.debian-practice:                 ||----w |
    student_debian_template.proxmox-iso.debian-practice:                 ||     ||
    student_debian_template.proxmox-iso.debian-practice:
    student_debian_template.proxmox-iso.debian-practice:  ________________________
    student_debian_template.proxmox-iso.debian-practice: < TASK [Gathering Facts] >
    student_debian_template.proxmox-iso.debian-practice:  ------------------------
    student_debian_template.proxmox-iso.debian-practice:         \   ^__^
    student_debian_template.proxmox-iso.debian-practice:          \  (oo)\_______
    student_debian_template.proxmox-iso.debian-practice:             (__)\       )\/\
    student_debian_template.proxmox-iso.debian-practice:                 ||----w |
    student_debian_template.proxmox-iso.debian-practice:                 ||     ||
    student_debian_template.proxmox-iso.debian-practice:
==> student_debian_template.proxmox-iso.debian-practice: failed to handshake
    student_debian_template.proxmox-iso.debian-practice: fatal: [default]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: Unable to negotiate with 127.0.0.1 port 39235: no matching host key type found. Their offer: ssh-rsa", "unreachable": true}

There is one thing that bothers me. It's the "ssh-rsa". the ssh key used is an ed25519 key, I have both an ed25519 key and an rsa key but it doesn't seem to work too.

[Syntax3rror404]

I have this same issue. But this works on vsphere so i think its a bug. But there is a workaround to solve this problem:

          }{% if provision_with_ansible %},
          {
                "type": "ansible",
                "playbook_file": "./playbook.yml",
                "extra_arguments": ["-e ansible_ssh_pass={{ ssh_password }}{% if debug is defined %} -vv{% endif %}"],
                "user": "{{ ssh_username }}"
          }
          {% endif %}

Add extra_arguments: ["-e ansible_ssh_pass=mypassword"] so ansible connects via username and password. You need sshpass installed on your system.

[kencx]

This issue is discussed in hashicorp/packer-plugin-ansible#69 and is a result of OpenSSH deprecating RSA/SHA-1. It has yet to be fixed but there are two workarounds available:

1. Turn off the proxy adapter if you do not need it:

provisioner "ansible" {
  ...
  use_proxy = false
  ...
}

2. Or allow SSH to accept the ssh-rsa algorithm:

provisioner "ansible" {
  ...
  ansible_ssh_extra_args = ["-oHostKeyAlgorithms=+ssh-rsa -oPubkeyAcceptedKeyTypes=+ssh-rsa -o IdentitiesOnly=yes"]
extra_arguments = [ "--scp-extra-args", "'-O'" ]
  ...
}