NOS-6672..NOS-6679: fboss2 bgp policy routing-policy term action commands

Adds `config protocol bgp policy routing-policy <name> term <seq-num>
action result <ACCEPT|REJECT|CONTINUE>` and `... action set
<attribute> <value> ...` — the action level of a routing-policy term.
`action` is a pure grouping node; `result` and `set` are its subcommands,
each with its own handler (the policy and term args arrive through the
ancestor-args tuple). The term traits drop positionals_at_end() so CLI11
can classify `action` (and later `match`) after the seq-num; ancestor
attributes mixed with an action command are rejected since only the leaf
runs.

`set` MUST be a real subcommand rather than a parsed token: CLI11's
_valid_subcommand walks the parent chain unconditionally, so a bare `set`
arg token inside `action` was classified as the top-level `set` VERB and
stolen ("The following arguments were not expected"). A local subcommand
named `set` shadows the verb because _find_subcommand checks the local
scope first.

- `result` (NOS-6672) maps ACCEPT/REJECT/CONTINUE onto FlowControlAction
  ACCEPT/DENY/NEXT_TERM in term_miss_action. GOTO-TERM stays deferred: no
  FlowControlAction arm, and the per-action-entry next_term_id target has
  no slot in the documented grammar.
- `set <attr>` writes one bgp_policy.BgpPolicyAction entry per action kind
  in policy_entries[].policy_action_entries[] (keyed by which payload field
  is set; re-issuing a kind updates its entry):
  - as-path prepend <asn> [<asn> ...] (NOS-6673) -> SetAsPathPrepend{asn,
    repeat_times}; the documented <asn-list> must be uniform since the
    thrift models one ASN repeated N times
  - community <community-string> [additive] (NOS-6674) -> inline
    single-member CommunityList + route_action COMMUNITY_LIST_ADD/SET
  - local-pref <0-4294967295> (NOS-6675) -> LocalPreference.local_pref
  - med <0-4294967295> (NOS-6676) -> MedAction{med_value, SET}
  - next-hop <ip-address> (NOS-6677) -> SetNextHop; the sheet's `self`
    (bgpd rejects set_self) and `peer-address` (no thrift arm) are deferred
  - origin <IGP|EGP|INCOMPLETE> (NOS-6678) -> set_origin
  - weight <0-65535> (NOS-6679) -> WeightAction{weight_value, SET}
- unit tests (12) + a commit-path integration test staging every action
  kind and verifying each entry in bgpd's running config.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: hillol-nexthop

cmake/CliFboss2.cmake

@@ -904,6 +904,8 @@ add_library(fboss2_config_lib
   fboss/cli/fboss2/commands/config/protocol/bgp/policy/routing-policy/BgpRoutingPolicyCliUtils.h
   fboss/cli/fboss2/commands/config/protocol/bgp/policy/routing-policy/term/CmdConfigProtocolBgpPolicyRoutingPolicyTerm.cpp
   fboss/cli/fboss2/commands/config/protocol/bgp/policy/routing-policy/term/CmdConfigProtocolBgpPolicyRoutingPolicyTerm.h
+  fboss/cli/fboss2/commands/config/protocol/bgp/policy/routing-policy/term/action/CmdConfigProtocolBgpPolicyRoutingPolicyTermAction.cpp
+  fboss/cli/fboss2/commands/config/protocol/bgp/policy/routing-policy/term/action/CmdConfigProtocolBgpPolicyRoutingPolicyTermAction.h
   fboss/cli/fboss2/commands/config/ptp/CmdConfigPtp.cpp
   fboss/cli/fboss2/commands/config/ptp/CmdConfigPtp.h
   fboss/cli/fboss2/commands/config/ptp/transparent_clock/CmdConfigPtpTransparentClock.cpp

cmake/CliFboss2TestConfig.cmake

@@ -16,6 +16,7 @@ add_executable(fboss2_cmd_config_test
   fboss/cli/fboss2/test/config/CmdConfigBgpPolicyPrefixListTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigBgpPolicyRoutingPolicyTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigBgpPolicyRoutingPolicyTermTest.cpp
+  fboss/cli/fboss2/test/config/CmdConfigBgpPolicyRoutingPolicyTermActionTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigCoppTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigDhcpTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigHostnameTest.cpp

cmake/CliFboss2TestIntegrationTest.cmake

@@ -18,6 +18,7 @@ add_executable(fboss2_integration_test
   fboss/cli/fboss2/test/integration_test/ConfigBgpPolicyPrefixListTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigBgpPolicyRoutingPolicyTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigBgpPolicyRoutingPolicyTermTest.cpp
+  fboss/cli/fboss2/test/integration_test/ConfigBgpPolicyRoutingPolicyTermActionTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigBgpSessionTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigConcurrentSessionsTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigHostnameTest.cpp

fboss/cli/fboss2/BUCK

@@ -1110,6 +1110,7 @@ cpp_library(
         "commands/config/protocol/bgp/policy/prefix-list/entry/CmdConfigProtocolBgpPolicyPrefixListEntry.cpp",
         "commands/config/protocol/bgp/policy/routing-policy/CmdConfigProtocolBgpPolicyRoutingPolicy.cpp",
         "commands/config/protocol/bgp/policy/routing-policy/term/CmdConfigProtocolBgpPolicyRoutingPolicyTerm.cpp",
+        "commands/config/protocol/bgp/policy/routing-policy/term/action/CmdConfigProtocolBgpPolicyRoutingPolicyTermAction.cpp",
         "commands/config/protocol/static/CmdConfigProtocolStatic.cpp",
         "commands/config/protocol/static/route/add/CmdConfigProtocolStaticRouteAdd.cpp",
         "commands/config/ptp/CmdConfigPtp.cpp",
@@ -1229,6 +1230,7 @@ cpp_library(
         "commands/config/protocol/bgp/policy/routing-policy/CmdConfigProtocolBgpPolicyRoutingPolicy.h",
         "commands/config/protocol/bgp/policy/routing-policy/BgpRoutingPolicyCliUtils.h",
         "commands/config/protocol/bgp/policy/routing-policy/term/CmdConfigProtocolBgpPolicyRoutingPolicyTerm.h",
+        "commands/config/protocol/bgp/policy/routing-policy/term/action/CmdConfigProtocolBgpPolicyRoutingPolicyTermAction.h",
         "commands/config/protocol/static/CmdConfigProtocolStatic.h",
         "commands/config/protocol/static/route/StaticRouteUtils.h",
         "commands/config/protocol/static/route/add/CmdConfigProtocolStaticRouteAdd.h",

fboss/cli/fboss2/CmdListConfig.cpp

@@ -50,6 +50,7 @@
 #include "fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/entry/CmdConfigProtocolBgpPolicyPrefixListEntry.h"
 #include "fboss/cli/fboss2/commands/config/protocol/bgp/policy/routing-policy/CmdConfigProtocolBgpPolicyRoutingPolicy.h"
 #include "fboss/cli/fboss2/commands/config/protocol/bgp/policy/routing-policy/term/CmdConfigProtocolBgpPolicyRoutingPolicyTerm.h"
+#include "fboss/cli/fboss2/commands/config/protocol/bgp/policy/routing-policy/term/action/CmdConfigProtocolBgpPolicyRoutingPolicyTermAction.h"
 #include "fboss/cli/fboss2/commands/config/protocol/static/CmdConfigProtocolStatic.h"
 #include "fboss/cli/fboss2/commands/config/protocol/static/route/add/CmdConfigProtocolStaticRouteAdd.h"
 #include "fboss/cli/fboss2/commands/config/ptp/CmdConfigPtp.h"
@@ -478,6 +479,30 @@ const CommandTree& kConfigCommandTree() {
                                        CmdConfigProtocolBgpPolicyRoutingPolicyTerm>,
                                    argRegistrar<
                                        CmdConfigProtocolBgpPolicyRoutingPolicyTermTraits>,
+                                   {{
+                                       "action",
+                                       "Configure a term action",
+                                       {{
+                                            "result",
+                                            "Set the term result: "
+                                            "<ACCEPT|REJECT|CONTINUE>",
+                                            commandHandler<
+                                                CmdConfigProtocolBgpPolicyRoutingPolicyTermActionResult>,
+                                            argRegistrar<
+                                                CmdConfigProtocolBgpPolicyRoutingPolicyTermActionResultTraits>,
+                                        },
+                                        {
+                                            "set",
+                                            "Set a route attribute: "
+                                            "as-path prepend|community|"
+                                            "local-pref|med|next-hop|"
+                                            "origin|weight <value> ...",
+                                            commandHandler<
+                                                CmdConfigProtocolBgpPolicyRoutingPolicyTermActionSet>,
+                                            argRegistrar<
+                                                CmdConfigProtocolBgpPolicyRoutingPolicyTermActionSetTraits>,
+                                        }},
+                                   }},
                                }},
                            }},
                       },

fboss/cli/fboss2/commands/config/protocol/bgp/policy/routing-policy/term/CmdConfigProtocolBgpPolicyRoutingPolicyTerm.h

@@ -61,9 +61,11 @@ struct CmdConfigProtocolBgpPolicyRoutingPolicyTermTraits
     : public WriteCommandTraits {
   using ParentCmd = CmdConfigProtocolBgpPolicyRoutingPolicy;
   static void addCliArg(CLI::App& cmd, std::vector<std::string>& args) {
-    // Term has no nested subcommands; stop CLI11's parent-chain fallthrough
-    // from stealing a value token that spells `term` (e.g. in a description).
-    cmd.positionals_at_end();
+    // No positionals_at_end() here: the term's action (and later match)
+    // level is a real CLI11 subcommand, and positionals_at_end() would stop
+    // CLI11 from classifying it after the seq-num. The trade-off is that a
+    // term-level attribute value spelling a child subcommand name is stolen
+    // by subcommand matching (same exposure as the routing-policy parent).
     cmd.add_option("args", args, "<seq-num> [<attribute> <value> ...]");
   }
   using ObjectArgType = BgpRoutingPolicyTermConfig;