[202205][buffers] Add 'create_only_config_db_buffers.json' file for the Mellanox devices (not MSFT SKU)

[vadymhlushko-mlnx]

DEPENDS ON: [202205][buffers] Add handler for the 'create_only_config_db_buffers' configuration knob

Why I did it

Add the create_only_config_db_buffers attribute to the DEVICE_METADATA|localhost. If the "create_only_config_db_buffers" exists and is equal to "true" - the buffers will be created according to the config_db configuration (for example BUFFER_QUEUE|* table), otherwise the maximum available buffers (which are read from SAI) will be created, regardless of the CONFIG_DB buffers configuration.

Work item tracking

• Microsoft ADO (number only):

How I did it

Add the create_only_config_db_buffers.json files for Mellanox devices (not MSFT SKU's), and inject the content to the CONFIG_DB during the swss docker container start.

How to verify it

Manual verification:

1. Install the image with this PR included on the not MSFT SKU switch
2. Check the show queue counters output and verify that only configured in CONFIG_DB buffers are created

root@sonic:/home/admin# show queue counters
     Port    TxQ    Counter/pkts    Counter/bytes    Drop/pkts    Drop/bytes
---------  -----  --------------  ---------------  -----------  ------------
Ethernet0    UC0               0                0            0           N/A
Ethernet0    UC1               0                0            0           N/A
Ethernet0    UC2               0                0            0           N/A
Ethernet0    UC3               0                0            0           N/A
Ethernet0    UC4               0                0            0           N/A
Ethernet0    UC5               0                0            0           N/A
Ethernet0    UC6               0                0            0           N/A

3. Open the /usr/share/sonic/device/$DEVICE/$SKU/create_only_config_db_buffers.json and change it to:

"create_only_config_db_buffers": "false"

4. Do config reload
5. Check the show queue counters output and verify that all available buffers are created

root@sonic:/home/admin# show queue counters
     Port    TxQ    Counter/pkts    Counter/bytes    Drop/pkts    Drop/bytes
---------  -----  --------------  ---------------  -----------  ------------
Ethernet0    UC0               0                0            0           N/A
Ethernet0    UC1               0                0            0           N/A
Ethernet0    UC2               0                0            0           N/A
Ethernet0    UC3               0                0            0           N/A
Ethernet0    UC4               0                0            0           N/A
Ethernet0    UC5               0                0            0           N/A
Ethernet0    UC6               0                0            0           N/A
Ethernet0    UC7              60            15346            0           N/A
Ethernet0    MC8             N/A              N/A          N/A           N/A
Ethernet0    MC9             N/A              N/A          N/A           N/A
Ethernet0   MC10             N/A              N/A          N/A           N/A
Ethernet0   MC11             N/A              N/A          N/A           N/A
Ethernet0   MC12             N/A              N/A          N/A           N/A
Ethernet0   MC13             N/A              N/A          N/A           N/A
Ethernet0   MC14             N/A              N/A          N/A           N/A
Ethernet0   MC15             N/A              N/A          N/A           N/A

Which release branch to backport (provide reason below if selected)

• 201811
• 201911
• 202006
• 202012
• 202106
• 202111
• 202205
• 202211
• 202305

Tested branch (Please provide the tested image version)

Description for the changelog

Link to config_db schema for YANG module changes

A picture of a cute animal (not mandatory but encouraged)

[dgsudharsan]

Please add yang model changes for the new config_db field.

[vadymhlushko-mlnx]

Please add yang model changes for the new config_db field.

Done

[vadymhlushko-mlnx]

@abdosi @prsunny could you please approve and merge?