Ansible SSH error when running provision playbook on Ubuntu images

[aguduszeit]

Overview of the Issue

When building Ubuntu images, ansible failed to connect to the VM with ssh with the following error:

Failed to connect to the host via ssh: Unable to negotiate with 127.0.0.1 port 38741: no matching host key type found. Their offer: ssh-rsa

Reproduction Steps

Command to run
packer build \ -force -on-error=ask \ --only vsphere-iso.linux-ubuntu \ -var-file="config/vsphere.pkrvars.hcl" \ -var-file="config/ansible.pkrvars.hcl" \ -var-file="config/build.pkrvars.hcl" \ -var-file="config/common.pkrvars.hcl" \ builds/linux/ubuntu/22-04-lts

Packer Version

Packer 1.8.0

Plugin Version and Builders

vsphere-plugin 1.0.4
Builder: builds/linux/ubuntu/18-04-lts/linux-ubuntu.pkr.hcl

• vsphere-iso
• [] vsphere-clone

VMware vSphere Version

VMware vSphere version: 7.0.2

Guest Operating System

Ubuntu 22.04 LTS x64
Ubuntu 18.04 LTS x64

Simplified Packer Buildfile

No change on the build file

Operating System and Environment Details

Kali Linux on wsl2

Log Fragments and crash.log Files

2022/05/26 01:23:47 packer-provisioner- plugin: -playbook version: 2.12.4
2022/05/26 01:23:47 ui: ==> vsphere-iso.linux-ubuntu: Provisioning with Ansible...
2022/05/26 01:23:47 ui: vsphere-iso.linux-ubuntu: Setting up proxy adapter for Ansible....
2022/05/26 01:23:47 packer-provisioner- plugin: Creating inventory file for Ansible run...
2022/05/26 01:23:47 packer-provisioner- plugin: SSH proxy: serving on 127.0.0.1:38067
2022/05/26 01:23:47 ui: ==> vsphere-iso.linux-ubuntu: Executing Ansible: -playbook -e packer_build_name="linux-ubuntu" -e packer_builder_type=vsphere-iso -e packer_http_addr=172.30.105.111:0 --ssh-extra-args '-o IdentitiesOnly=yes' --extra-vars display_skipped_hosts=false --extra-vars BUILD_USERNAME= --extra-vars BUILD_SECRET=***** --extra-vars ANSIBLE_USERNAME= --extra-vars ANSIBLE_SECRET=***** -e _ssh_private_key_file=/tmp/-key3651137202 -i /tmp/packer-provisioner-2855013751 /tmp/packer-examples-for-vsphere//main.yml
2022/05/26 01:23:47 ui: vsphere-iso.linux-ubuntu: [DEPRECATION WARNING]: COMMAND_WARNINGS option, the command warnings feature is
2022/05/26 01:23:47 ui: vsphere-iso.linux-ubuntu: being removed. This feature will be removed from -core in version 2.14.
2022/05/26 01:23:47 ui: vsphere-iso.linux-ubuntu: Deprecation warnings can be disabled by setting deprecation_warnings=False in
2022/05/26 01:23:47 ui: vsphere-iso.linux-ubuntu: .cfg.
2022/05/26 01:23:48 ui: vsphere-iso.linux-ubuntu:
2022/05/26 01:23:48 ui: vsphere-iso.linux-ubuntu: PLAY [all] *********************************************************************
2022/05/26 01:23:48 packer-provisioner- plugin: SSH proxy: accepted connection
2022/05/26 01:23:48 ui error: ==> vsphere-iso.linux-ubuntu: failed to handshake
2022/05/26 01:23:48 ui: vsphere-iso.linux-ubuntu:
2022/05/26 01:23:48 ui: vsphere-iso.linux-ubuntu: TASK [Gathering Facts] *********************************************************
2022/05/26 01:23:48 ui: vsphere-iso.linux-ubuntu: fatal: [default]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: Unable to negotiate with 127.0.0.1 port 38067: no matching host key type found. Their offer: ssh-rsa", "unreachable": true}
2022/05/26 01:23:48 ui: vsphere-iso.linux-ubuntu:
2022/05/26 01:23:48 ui: vsphere-iso.linux-ubuntu: PLAY RECAP *********************************************************************
2022/05/26 01:23:48 ui: vsphere-iso.linux-ubuntu: default : ok=0 changed=0 unreachable=1 failed=0 skipped=0 rescued=0 ignored=0
2022/05/26 01:23:48 ui: vsphere-iso.linux-ubuntu:
2022/05/26 01:23:48 packer-provisioner- plugin: shutting down the SSH proxy
2022/05/26 01:23:48 [INFO] (telemetry) ending
2022/05/26 01:23:48 ui error: ==> vsphere-iso.linux-ubuntu: Error executing Ansible: Non-zero exit status: exit status 4

[nywilken]

👋 Hi @aguduszeit I believe this issue has been resolved with the latest release of the Ansible and vSphere plugins. Can you please upgrade your versions of the plugins to the latest version and try again.

[tenthirtyam]

The issue is with Linux system configuration for SSH. This is similarly noted noted in the CHANGELOG.md in main for the upcoming project release based on testing with adding Ubuntu 22.04 LTS and Photon OS 4 as a supported Packer host.

Solution:

Update /etc/ssh/ssh_config or your .ssh/ssh_config or to allow authentication with RSA keys:

PubkeyAcceptedAlgorithms ssh-rsa
HostkeyAlgorithms ssh-rsa

See vmware-samples/packer-examples-for-vsphere#207 for the same closed issue by @aguduszeit.

Hope that helps.

Ryan Johnson
Staff II Solutions Architect | VMware, Inc.

[tenthirtyam]

@nywilken - this one can be closed.

See vmware-samples/packer-examples-for-vsphere#207 for the same closed issue by @aguduszeit.

Ryan Johnson
Staff II Solutions Architect | VMware, Inc.

[nywilken]

@tenthirtyam thanks for the update on this issue. I see the fix being a change to the SSH configuration for the OS under build. I am curious if this change is still needed after the vSphere v1.0.3 plugin release which contained a fix to the Go crypto/ssh client containing a fix for legacy key algorithms. See details here

I'm going to close this issue but feel free to drop a comment if you have anything to add about ☝️

[tenthirtyam]

I actually tested it today with v1.0.5 and it was still required.

It might be possible to modify the ansible.cfg to pass ssh_args, but I've not had any luck with that approach.

Ryan Johnson
Staff II Solutions Architect | VMware, Inc.