SAI_POLICER_ATTR_METER_TYPE meta_generic_validation_set error

[jipanyang]

Attribute SAI_POLICER_ATTR_METER_TYPE is create only, while CoppOrch::processCoppRule() provided set interface for it.

https://github.com/Azure/sonic-swss/blob/136621b497d8a51577c7a33e67c7d0fb68a04f2d/orchagent/copporch.cpp#L379

Aug 17 21:10:39.473234 sonic ERR swss/orchagent: :- meta_generic_validation_set: SAI_POLICER_ATTR_METER_TYPE:SAI_ATTR_VALUE_TYPE_INT32 attr is create only and cannot be modified
Aug 17 21:10:39.473345 sonic ERR swss/orchagent: :- processCoppRule: Failed to apply attribute[2].id=0 to policer for trap group:default, error:-5
Aug 17 21:10:39.473345 sonic ERR swss/orchagent: :- doTask: Processing copp task item failed, exiting. 

    /**
     * @brief Policer Meter Type
     *
     * @type sai_meter_type_t
     * @flags MANDATORY_ON_CREATE | CREATE_ONLY
     */
    SAI_POLICER_ATTR_METER_TYPE = SAI_POLICER_ATTR_START,

[lguohan]

does it make sense to change the type?

[jipanyang]

It will be if possible. Actually there are few other create only attributes in saipolicer.h
We either make them create and set, or update SONiC code logic to handle them properly.

    /**
     * @brief Policer Meter Type
     *
     * @type sai_meter_type_t
     * @flags MANDATORY_ON_CREATE | CREATE_ONLY
     */
    SAI_POLICER_ATTR_METER_TYPE = SAI_POLICER_ATTR_START,

    /**
     * @brief Policer mode
     *
     * @type sai_policer_mode_t
     * @flags MANDATORY_ON_CREATE | CREATE_ONLY
     */
    SAI_POLICER_ATTR_MODE = 0x00000001,

    /**
     * @brief Policer Color Source
     *
     * @type sai_policer_color_source_t
     * @flags CREATE_ONLY
     * @default SAI_POLICER_COLOR_SOURCE_AWARE
     */
    SAI_POLICER_ATTR_COLOR_SOURCE = 0x00000002,

[stcheng]

before the discussion in SAI resolves this issue, we could first block the route to 'set' in SONiC