[202211] [sflowmgrd] Infer sampling rate dynamically based on oper speed

[vivekrnv]

What I did

Backport #2799 to 2211

1. Remove sflowSpeedRateInitMap and infer the default sampling rate based on speed on the interface.
2. Make the rate inference based on oper_speed.

Why I did it

1. With Static Map, adding a new speed would require updating the code.
2. auotneg might change the operational speed on the port but the default sampling rate is not updated

How I verified it

1. UT's:

vkarri@3e8d51f2fa45:/sonic/src/sonic-swss/tests/mock_tests$ ./tests --gtest_filter="*SflowMgrTest*"
Running main() from /build/googletest-YnT0O3/googletest-1.10.0.20201025/googletest/src/gtest_main.cc
Note: Google Test filter = *SflowMgrTest*
[==========] Running 8 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 8 tests from SflowMgrTest
[ RUN      ] SflowMgrTest.test_RateConfiguration
[       OK ] SflowMgrTest.test_RateConfiguration (0 ms)
[ RUN      ] SflowMgrTest.test_RateConfigurationCfgSpeed
[       OK ] SflowMgrTest.test_RateConfigurationCfgSpeed (1 ms)
[ RUN      ] SflowMgrTest.test_OnlyStateDbNotif
[       OK ] SflowMgrTest.test_OnlyStateDbNotif (0 ms)
[ RUN      ] SflowMgrTest.test_LocalRateConfiguration
[       OK ] SflowMgrTest.test_LocalRateConfiguration (0 ms)
[ RUN      ] SflowMgrTest.test_LocalRateConfWithOperSpeed
[       OK ] SflowMgrTest.test_LocalRateConfWithOperSpeed (0 ms)
[ RUN      ] SflowMgrTest.test_newSpeed
[       OK ] SflowMgrTest.test_newSpeed (0 ms)
[ RUN      ] SflowMgrTest.test_CfgSpeedAdminCfg
[       OK ] SflowMgrTest.test_CfgSpeedAdminCfg (0 ms)
[ RUN      ] SflowMgrTest.test_OperSpeedAdminCfg
[       OK ] SflowMgrTest.test_OperSpeedAdminCfg (1 ms)
[----------] 8 tests from SflowMgrTest (2 ms total)

[----------] Global test environment tear-down
[==========] 8 tests from 1 test suite ran. (2 ms total)
[  PASSED  ] 8 tests.

2. Run manual tests on a DUT

Test normal speed change without autoneg

root@dut:/home/admin# show sflow interface | grep Ethernet220
| Ethernet220 | up            |          100000 |

root@dut:/home/admin# config interface speed Ethernet220 50000
root@dut:/home/admin# show sflow interface | grep Ethernet220
| Ethernet220 | up            |           50000 |

root@dut:/home/admin# config interface speed Ethernet220 25000
root@dut:/home/admin# show sflow interface | grep Ethernet220
| Ethernet220 | up            |           25000 |

Test rate change with autoneg

Ethernet205 <-> Ethernet209 Back to back connected

root@dut:/# show interfaces status 
Ethernet205              205      25G   9100    N/A   etp52b  routed      up       up    QSFP28 or later         N/A
Ethernet209              209      25G   9100    N/A   etp53b  routed      up       up    QSFP28 or later         N/A

<Check sampling rate before >
root@dut:/# show sflow interface
| Ethernet205 | up            |           25000 |
| Ethernet209 | up            |           25000 |

<Enable autoneg on 209>
root@dut:/# config interface autoneg Ethernet209 enabled
<Change speed on the peer port>
root@dut:/# config interface speed Ethernet205 10000

<Speed on 209 is updated because of autoneg>
root@dut:/# show interfaces status 
Ethernet205              205      10G   9100    N/A   etp52b  routed      up       up   QSFP28 or later         N/A
Ethernet209              209      10G   9100    N/A   etp53b  routed      up       up   QSFP28 or later         N/A

<sampling rate updated on both the ports>    
root@dut:/# show sflow interface
| Ethernet205 | up            |           10000 |
| Ethernet209 | up            |           10000 |

<disable autoneg> 
root@dut:/# config interface autoneg Ethernet209 disabled

root@dut:/# show sflow interface
| Ethernet205 | up            |           10000 |
| Ethernet209 | up            |           10000 |

[vivekrnv]

/azpw run Azure.sonic-swss

[mssonicbld]

/AzurePipelines run Azure.sonic-swss

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[dgsudharsan]

@Gokulnath-Raja Can you please review and signoff this backport?