PROD-22: Serverless functions (2600hz#5911)

Allow developers to upload Javascript functions to KAZOO to be run on
the local infrastructure instead of incurring the cost of an HTTP
request to the developer's infrastructure via Pivot.

run the functions via the callflow action

includes adding 'aggregate' databases as storage plan options, and a
filter for which databases to consider.

add examples of user-defined Javascript functions

Updates couchbeam to include the Show API functionality

 start to address compaints

fix module names and tested

remove kapi functions schemas

remove more functions-related stuff

remove functions

.gitignore

@@ -90,3 +90,4 @@ core/kazoo_proper/priv/mp3.mp3
 /doc/engineering/.org/proper.pdf
 /doc/engineering/.org/proper.tex
 /todo.org
+*.tar

applications/callflow/doc/function.md

@@ -0,0 +1,19 @@
+## Function
+
+### About Function
+
+Runs the function in the local infrastructure to create a new callflow to branch to.
+
+#### Schema
+
+Validator for the function callflow data object
+
+
+
+Key | Description | Type | Default | Required | Support Level
+--- | ----------- | ---- | ------- | -------- | -------------
+`id` | The Function's doc ID | `string()` |   | `false` |  
+`skip_module` | When set to true this callflow action is skipped, advancing to the wildcard branch (if any) | `boolean()` |   | `false` |  
+
+
+

applications/callflow/doc/ref/function.md

@@ -0,0 +1,17 @@
+## Function
+
+### About Function
+
+#### Schema
+
+Validator for the function callflow data object
+
+
+
+Key | Description | Type | Default | Required | Support Level
+--- | ----------- | ---- | ------- | -------- | -------------
+`id` | The Function's doc ID | `string()` |   | `false` |  
+`skip_module` | When set to true this callflow action is skipped, advancing to the wildcard branch (if any) | `boolean()` |   | `false` |  
+
+
+

applications/callflow/src/callflow.app.src

@@ -4,7 +4,8 @@
                              kazoo_documents,kazoo_edr,kazoo_endpoint,
                              kazoo_globals,kazoo_media,kazoo_number_manager,
                              kazoo_schemas,kazoo_stdlib,kazoo_token_buckets,
-                             kazoo_voicemail,kazoo_web,kernel,lager,stdlib]},
+                             kazoo_translator,kazoo_voicemail,kazoo_web,
+                             kernel,lager,stdlib]},
               {description,"Callflow - traversing through the tree..."},
               {env,[{is_kazoo_app,true}]},
               {mod,{callflow_app,[]}},

applications/callflow/src/callflow_app.erl

@@ -35,7 +35,7 @@ start(_Type, _Args) ->
 
 -spec prep_stop(any()) -> 'ok'.
 prep_stop(_State) ->
-    kz_nodes:unbind_for_pool_state('kz_amqp_sup', whereis('callflow_sup')),
+    _ = kz_nodes:unbind_for_pool_state('kz_amqp_sup', whereis('callflow_sup')),
     'ok'.
 
 %%------------------------------------------------------------------------------

applications/callflow/src/module/cf_function.erl

@@ -0,0 +1,86 @@
+%%%-----------------------------------------------------------------------------
+%%% @copyright (C) 2012-2019, 2600Hz
+%%% @doc Accept customized `dialplan'.
+%%%
+%%% <h4>Data options:</h4>
+%%% <dl>
+%%%   <dt>`function_ref'</dt>
+%%%   <dd> a couchDB document Id reference to retrieve Javascript function.</dd>
+%%%
+%%%   <dt>`language_pack'</dt>
+%%%   <dd> the language and version are required for the function runtime.</dd>
+%%%
+%%%   <dt>`skip_module'</dt>
+%%%   <dd>`boolean()'.</dd>
+%%%
+%%%   <dt>`debug'</dt>
+%%%   <dd>`boolean()'</dd>
+%%% </dl>
+%%%
+%%% @author Ming Luo
+%%% This Source Code Form is subject to the terms of the Mozilla Public
+%%% License, v. 2.0. If a copy of the MPL was not distributed with this
+%%% file, You can obtain one at https://mozilla.org/MPL/2.0/.
+%%%
+%%% @end
+%%%-----------------------------------------------------------------------------
+-module(cf_function).
+
+-behaviour(gen_cf_action).
+
+-include("callflow.hrl").
+
+-export([handle/2
+        ,run_function/2
+        ]).
+
+%%------------------------------------------------------------------------------
+%% @doc Entry point for this module, attempts to call an endpoint as defined
+%% in the Data payload.  Returns continue if fails to connect or
+%% stop when successful.
+%%
+%% Expected data payload:
+%%   id: string(), the function ID for the account
+%% @end
+%%------------------------------------------------------------------------------
+-spec handle(kz_json:object(), kapps_call:call()) -> 'ok'.
+handle(Data, Call) ->
+    %% add language_pack support for other language and versions.
+    FunctionId = kz_json:get_ne_binary_value(<<"id">>, Data),
+    case run_function(FunctionId, Call) of
+        {'ok', Flow} ->
+            maybe_branch(Flow, Call);
+        {'error', _E} ->
+            lager:info("error for ~s: ~p", [FunctionId, _E]),
+            cf_exe:continue(Call)
+    end.
+
+-spec run_function(kz_term:ne_binary(), kapps_call:call()) -> {'ok', kz_json:object()} |
+                                                              kz_datamgr:data_error().
+run_function(FunctionId, Call) ->
+    BaseParams = kzt_kazoo:req_params(Call),
+    UserParams = kzt_translator:get_user_vars(Call),
+    Params = kz_json:set_values(BaseParams, UserParams),
+
+    QueryString = kz_http_util:json_to_querystring(Params),
+    kz_datamgr:show(?KZ_FUNCTIONS_DB, <<"functions/wh">>, FunctionId, options(QueryString)).
+
+-spec options(iodata()) -> [{'query_string', binary()}].
+options([]) -> [];
+options(<<>>) -> [];
+options(QueryString) ->
+    [{'query_string', kz_term:to_binary(QueryString)}].
+
+-spec maybe_branch(kz_json:object(), kapps_call:call()) -> 'ok'.
+maybe_branch(FlowJObj, Call) ->
+    case kzd_callflows:validate_flow(
+           kzd_callflows:set_flow(kzd_callflows:new(), FlowJObj)
+          )
+    of
+        {'error', Errors} ->
+            lager:info("error validating flow: ~p", [Errors]),
+            cf_exe:continue(Call);
+        {'ok', ValidCallflow} ->
+            lager:info("branching callflow to ~p", [ValidCallflow]),
+            cf_exe:branch(kzd_callflows:flow(ValidCallflow), Call)
+    end.