MB-47766 Support for analytics settings manager

The analytics settings manager is patterned after the eventing settings
manager and so far provides support for numReplicas.

$ curl -s -u Administrator:asdasd localhost:9000/settings/analytics | jq
{
  "numReplicas": 0
}

$ curl -s -u Administrator:asdasd localhost:9000/settings/analytics \
         -d "numReplicas=5"
{"numReplicas":5}

$ curl -s -u Administrator:asdasd localhost:9000/settings/analytics | jq
{
  "numReplicas": 5
}

An audit event for the modification is also provided.

Change-Id: Ib2caf4b28fee1ff111e4126140cd435d04b2b8be
Reviewed-on: http://review.couchbase.org/c/ns_server/+/159170
Well-Formed: Build Bot <[email protected]>
Reviewed-by: Artem Stemkovski <[email protected]>
Tested-by: Build Bot <[email protected]>

Author: stevewatanabe

etc/audit_descriptor.json

@@ -1323,6 +1323,25 @@
           "optional_fields" : {
               "sessionid" : ""
           }
+      },
+      {
+          "id" : 8267,
+          "name" : "modify analytics settings",
+          "description" : "Analytics service settings were modified",
+          "sync" : false,
+          "enabled" : true,
+          "filtering_permitted" : false,
+          "mandatory_fields" : {
+              "timestamp" : "",
+              "real_userid" : {"source" : "", "user" : ""},
+              "remote" : {"ip" : "", "port" : 1},
+              "local" : {"ip" : "", "port" : 1},
+              "settings" : ""
+          },
+          "optional_fields" : {
+              "sessionid" : ""
+          }
       }
+
     ]
 }

src/analytics_settings_manager.erl

@@ -0,0 +1,71 @@
+%% @author Couchbase <[email protected]>
+%% @copyright 2021-Present Couchbase, Inc.
+%%
+%% Use of this software is governed by the Business Source License included
+%% in the file licenses/BSL-Couchbase.txt.  As of the Change Date specified
+%% in that file, in accordance with the Business Source License, use of this
+%% software will be governed by the Apache License, Version 2.0, included in
+%% the file licenses/APL2.txt.
+%%
+-module(analytics_settings_manager).
+
+-include("ns_common.hrl").
+
+-behavior(json_settings_manager).
+
+-export([start_link/0,
+         get/1,
+         get_from_config/3,
+         update/2,
+         config_default/0]).
+
+-export([cfg_key/0,
+         is_enabled/0,
+         known_settings/0,
+         on_update/2]).
+
+-import(json_settings_manager,
+        [id_lens/1]).
+
+-define(ANALYTICS_CONFIG_KEY, {metakv, <<"/analytics/settings/config">>}).
+
+start_link() ->
+    json_settings_manager:start_link(?MODULE).
+
+get(Key) ->
+    json_settings_manager:get(?MODULE, Key, []).
+
+get_from_config(Config, Key, Default) ->
+    json_settings_manager:get_from_config(?MODULE, Config, Key, Default).
+
+cfg_key() ->
+    ?ANALYTICS_CONFIG_KEY.
+
+is_enabled() ->
+    cluster_compat_mode:is_cluster_NEO().
+
+on_update(_Key, _Value) ->
+    ok.
+
+update(Key, Value) ->
+    json_settings_manager:update(?MODULE, [{Key, Value}]).
+
+config_default() ->
+    {?ANALYTICS_CONFIG_KEY, json_settings_manager:build_settings_json(
+                 default_settings(), dict:new(), known_settings())}.
+
+known_settings() ->
+    [{generalSettings, general_settings_lens()}].
+
+default_settings() ->
+    [{generalSettings, general_settings_defaults()}].
+
+general_settings() ->
+    [{numReplicas, "analytics.settings.num_replicas", 0}].
+
+general_settings_defaults() ->
+    [{K, D} || {K, _, D} <- general_settings()].
+
+general_settings_lens() ->
+    json_settings_manager:props_lens(
+      [{K, id_lens(list_to_binary(L))} || {K, L, _} <- general_settings()]).

src/menelaus_util.erl

@@ -64,6 +64,7 @@
          assert_is_enterprise/0,
          assert_is_65/0,
          assert_is_66/0,
+         assert_is_NEO/0,
          strip_json_struct/1,
          choose_node_consistently/2,
          compute_sec_headers/0,
@@ -624,6 +625,9 @@ assert_is_65() ->
 assert_is_66() ->
     assert_cluster_version(fun cluster_compat_mode:is_cluster_66/0).
 
+assert_is_NEO() ->
+    assert_cluster_version(fun cluster_compat_mode:is_cluster_NEO/0).
+
 assert_cluster_version(Fun) ->
     case Fun() of
         true ->

src/menelaus_web.erl

@@ -469,6 +469,9 @@ get_action(Req, {AppRoot, IsSSL, Plugins}, Path, PathTokens) ->
                      fun menelaus_web_indexes:handle_index_status/1};
                 ["settings", "indexes"] ->
                     {{[settings, indexes], read}, fun menelaus_web_indexes:handle_settings_get/1};
+                ["settings", "analytics"] ->
+                    {{[settings, analytics], read},
+                     fun menelaus_web_analytics:handle_settings_get/1};
                 ["diag"] ->
                     {{[admin, diag], read}, fun diag_handler:handle_diag/1, []};
                 ["diag", "vbuckets"] ->
@@ -847,6 +850,9 @@ get_action(Req, {AppRoot, IsSSL, Plugins}, Path, PathTokens) ->
                      fun menelaus_web_stats:handle_range_post/1, []};
                 ["settings", "indexes"] ->
                     {{[settings, indexes], write}, fun menelaus_web_indexes:handle_settings_post/1};
+                ["settings", "analytics"] ->
+                    {{[settings, analytics], write},
+                     fun menelaus_web_analytics:handle_settings_post/1};
                 ["_cbauth"] ->
                     {no_check, fun menelaus_cbauth:handle_cbauth_post/1};
                 ["_cbauth", "extractUserFromCert"] ->

src/menelaus_web_analytics.erl

@@ -0,0 +1,48 @@
+%% @author Couchbase <[email protected]>
+%% @copyright 2021-Present Couchbase, Inc.
+%% %% Use of this software is governed by the Business Source License included
+%% in the file licenses/BSL-Couchbase.txt.  As of the Change Date specified
+%% in that file, in accordance with the Business Source License, use of this
+%% software will be governed by the Apache License, Version 2.0, included in
+%% the file licenses/APL2.txt.
+%%
+-module(menelaus_web_analytics).
+
+-include("ns_common.hrl").
+-include("cut.hrl").
+-export([handle_settings_get/1, handle_settings_post/1]).
+
+handle_settings_get(Req) ->
+    menelaus_util:assert_is_NEO(),
+    Settings = get_settings(),
+    menelaus_util:reply_json(Req, {Settings}).
+
+get_settings() ->
+    analytics_settings_manager:get(generalSettings).
+
+settings_post_validators() ->
+    [validator:has_params(_),
+     validator:integer(numReplicas, 0, 16, _),
+     validator:unsupported(_)].
+
+update_settings(Key, Value) ->
+    case analytics_settings_manager:update(Key, Value) of
+        {ok, _} ->
+            ok;
+        retry_needed ->
+            erlang:error(exceeded_retries)
+    end.
+
+handle_settings_post(Req) ->
+    menelaus_util:assert_is_NEO(),
+    validator:handle(
+      fun (Values) ->
+              case Values of
+                  [] ->
+                      ok;
+                  _ ->
+                      ok = update_settings(generalSettings, Values),
+                      ns_audit:modify_analytics_settings(Req, Values)
+              end,
+              menelaus_util:reply_json(Req, {get_settings()})
+      end, Req, form, settings_post_validators()).

src/ns_audit.erl

@@ -68,6 +68,7 @@
          modify_index_settings/2,
          modify_query_curl_whitelist_setting/2,
          modify_query_settings/2,
+         modify_analytics_settings/2,
          read_doc/3,
          mutate_doc/4,
          set_user_group/6,
@@ -367,7 +368,9 @@ code(auth_failure) ->
 code(rbac_info_retrieved) ->
     8265;
 code(admin_password_reset) ->
-    8266.
+    8266;
+code(modify_analytics_settings) ->
+    8267.
 
 to_binary({list, List}) ->
     [to_binary(A) || A <- List];
@@ -827,6 +830,9 @@ print_audit_records(Queue) ->
 modify_index_settings(Req, Settings) ->
     put(modify_index_settings, Req, [{settings, {prepare_list(Settings)}}]).
 
+modify_analytics_settings(Req, Settings) ->
+    put(modify_analytics_settings, Req, [{settings, {prepare_list(Settings)}}]).
+
 modify_query_settings(Req, Settings) ->
     put(modify_query_settings, Req, [{settings, {prepare_list(Settings)}}]).
 

src/ns_config_default.erl

@@ -142,12 +142,12 @@ default() ->
      {{couchdb, max_parallel_indexers}, 4},
      {{couchdb, max_parallel_replica_indexers}, 2},
 
-     %% Default config for metakv index settings in minimum supported version,
+     %% Default config for metakv settings in minimum supported version for
+     %% the various services that use it.
      index_settings_manager:config_default(),
-     %% Default config for metakv eventing settings in minimum supported version
      eventing_settings_manager:config_default(),
-     %% Default config for metakv query settings in minimum supported version
      query_settings_manager:config_default(),
+     analytics_settings_manager:config_default(),
 
      %% {rest_creds, {User, {password, {Salt, Mac}}}}
      %% {rest_creds, null} means no login/password auth check.

src/ns_server_sup.erl

@@ -151,6 +151,9 @@ child_specs() ->
      {eventing_settings_manager, {eventing_settings_manager, start_link, []},
       permanent, 1000, worker, [work_queue]},
 
+     {analytics_settings_manager, {analytics_settings_manager, start_link, []},
+      permanent, 1000, worker, [analytics_settings_manager]},
+
      {audit_events,
       {gen_event, start_link, [{local, audit_events}]},
       permanent, brutal_kill, worker, dynamic},