[Nexthop] Add BGP thrift definitions

[manoharan-nexthop]

Pre-submission checklist

• I've ran the linters locally and fixed lint errors related to the files I modified in this PR. You can install the linters by running pip install -r requirements-dev.txt && pre-commit install
• pre-commit run

Summary

Adds the thrift interface definitions for BGP (Border Gateway Protocol) functionality. These thrift files define the data structures and service interfaces needed for BGP operations.

Thrift Files Added:

• fboss/bgp/if/bgp_thrift.thrift - Main BGP service interface (TBgpService) defining RPC methods for BGP operations, session management, RIB queries, policy management, and monitoring
• fboss/cli/fboss2/commands/show/bgp/summary/bgp_summary.thrift - BGP summary data model for CLI commands
• fboss/routing/policy/if/policy_thrift.thrift - Routing policy statistics stub

Build System Updates:

• CMakeLists.txt - Added thrift compilation targets for all BGP thrift files
• BUCK files - Added thrift library definitions for Meta-internal builds

Test Plan

[induvsuresh]

Thank you for the changes, overall lgtm! pls address the inline comments

[induvsuresh]

We were able to publish the OSS version of bgp_policy.thrift, rib_policy.thrift etc - https://github.com/facebook/fboss/tree/main/configerator/structs/neteng

Could we update the PR to drop these changes and use them directly
Thank you in advance!

[joseph5wu]

@manoharan-nexthop : I recently synced our BGP open-source ready thrift files in this folder in fboss repo:
https://github.com/facebook/fboss/tree/main/configerator/structs/neteng
Can you use these thrift files in cmake to support bgp cli?

[manoharan-nexthop]

@manoharan-nexthop : I recently synced our BGP open-source ready thrift files in this folder in fboss repo: https://github.com/facebook/fboss/tree/main/configerator/structs/neteng Can you use these thrift files in cmake to support bgp cli?

@joseph5wu, The bgp_config.thrift includes configerator/structs/neteng/config/vip_service_config.thrift which is not available yet. Will you be adding that as well?

Also, the main bgp service thrift file is not available yet which this PR introduces, should we leave that as is, or will you be bringing in that as well. Please let me know.

[induvsuresh]

@manoharan-nexthop : I recently synced our BGP open-source ready thrift files in this folder in fboss repo: https://github.com/facebook/fboss/tree/main/configerator/structs/neteng Can you use these thrift files in cmake to support bgp cli?

@joseph5wu, The bgp_config.thrift includes configerator/structs/neteng/config/vip_service_config.thrift which is not available yet. Will you be adding that as well?
vip_service_config will not be OSS'ed, @manoharan-nexthop could you help clean up the bgp_config.thrift and any other usages in the thrift and update

Also, the main bgp service thrift file is not available yet which this PR introduces, should we leave that as is, or will you be bringing in that as well. Please let me know.
When you say main thrift file do you mean bgp_thrift.thrift?

[induvsuresh]

bgp_thrift.thrift and policy_thrift have been published to the fboss OSS repo already, could we re-use that and that way this PR can have just the bgp_summary , its related BUCK and cmake file

[manoharan-nexthop]

Closing this PR, as #1039 already has this change (only this PR now has one thrift file change).