Topolog Installation Failure

Products

• Network Observability
• Topology

Issue/Introduction

After editing the inventory file, when we get to the ansible all -i inventory -m ping command. We see the following errors:

[WARNING]: Host 'DA' is using the discovered Python interpreter at '/usr/bin/python3', but future installation of another Python interpreter could cause a different interpreter to be discovered. See https://docs.ansible.com/ansible-core/2.19/reference_appendices/interpreter_discovery.html for more information.
[WARNING]: sftp transfer mechanism failed on [xxx.xx.xxx.xxx]. Use ANSIBLE_DEBUG=1 to see detailed information
[ERROR]: Task failed: Action failed: Module result deserialization failed: No start of json char found

 

Task failed: Action failed.
Origin: <adhoc 'ping' task>

 

{'action': 'ping', 'args': {}, 'timeout': 0, 'async_val': 0, 'poll': 15}

 

<<< caused by >>>

 

Module result deserialization failed: No start of json char found See stdout/stderr for the returned output.

 

DA | FAILED! => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "module_stderr": "Shared connection to 172.28.156.111 closed.\r\n",
    "module_stdout": "  File \"/home1/topology/.ansible/tmp/ansible-tmp-1761071559.6304965-3914603-40975257409292/AnsiballZ_ping.py\", line 3\r\n    from __future__ import annotations\r\n    ^\r\nSyntaxError: future feature annotations is not defined\r\n",
    "msg": "Module result deserialization failed: No start of json char found",
    "rc": 1
}

Interpreter Discovery — Ansible Core Documentation

Environment

Dx NetOps Topology 24.3.102

Resolution

Wrong version of Python installed

1. See https://docs.ansible.com/ansible/latest/reference_appendices/release_and_maintenance.html#ansible-core-support-matrix
2. Run ansible --version to get the ansible core version
3. Update python to the appropriate version based on the ansible core version
4. Resume installation

Note: If things are working as expected you may see 'Warnings'

 

Example:

[WARNING]: Host 'xxxx' is using the discovered Python interpreter at '/usr/bin/python3.12', but future installation of another Python interpreter could cause a different interpreter to be discovered. See https://docs.ansible.com/ansible-core/2.19/reference_appendices/interpreter_discovery.html for more information.
PMTS | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3.12"
    },
    "changed": false,
    "ping": "pong"

 

This indicates everything is working as expected.

Additional Information

Our documentation clearly outlines these prerequisites on the “Install and Configure Ansible” page: https://techdocs.broadcom.com/us/en/ca-enterprise-software/it-operations-management/performance-management/24-3/installing/install-ifm/prerequisites/install-and-configure-ansible.html.