[Testbed] Filter key-value pairs while retrieving SONiC version from /etc/sonic/sonic_version.yml

[lizhijianrd]

Description of PR

Summary:
The /etc/sonic/sonic_version.yml of SONiC 202205 looks like below:

---
build_version: '202205'
debian_version: '11.6'
kernel_version: '5.10.0-18-2-amd64'
asic_type: broadcom
asic_subtype: 'broadcom'
# ...

There is a --- line at the beginning of file and it causes the ansible playbook crush when deploying SONiC 202205 fanout switches. As we only need the key-value lines, I added grep ":" to filter the key-value lines when reading this file.

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Back port request

• 201911
• 202012
• 202205

Approach

What is the motivation for this PR?

There is a --- line at the beginning of /etc/sonic/sonic_version.yml in SONiC 202205 image, and it causes the ansible playbook crush when deploying fanout switches. I opened this PR to fix this issue.

How did you do it?

Added grep ":" to filter the key-value lines when reading this file.

How did you verify/test it?

Verified on physical testbeds.

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation