support release discovery in relcool along with app discovery

1 files changed, 166 insertions, 0 deletions

diff --git a/src/rcl_rel_discovery.erl b/src/rcl_rel_discovery.erl
new file mode 100644
index 0000000..0fbcf23
--- /dev/null
+++ b/src/rcl_rel_discovery.erl
@@ -0,0 +1,166 @@
+%% -*- erlang-indent-level: 4; indent-tabs-mode: nil; fill-column: 80 -*-
+%%% Copyright 2012 Erlware, LLC. All Rights Reserved.
+%%%
+%%% This file is provided to you under the Apache License,
+%%% Version 2.0 (the "License"); you may not use this file
+%%% except in compliance with the License.  You may obtain
+%%% a copy of the License at
+%%%
+%%%   http://www.apache.org/licenses/LICENSE-2.0
+%%%
+%%% Unless required by applicable law or agreed to in writing,
+%%% software distributed under the License is distributed on an
+%%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+%%% KIND, either express or implied.  See the License for the
+%%% specific language governing permissions and limitations
+%%% under the License.
+%%%---------------------------------------------------------------------------
+%%% @author Eric Merritt <[email protected]>
+%%% @copyright (C) 2012 Erlware, LLC.
+%%%
+%%% @doc This provider uses the lib_dir setting of the state. It searches the
+%%% Lib Dirs looking for all OTP Applications that are available. When it finds
+%%% those OTP Applications it loads the information about them and adds them to
+%%% the state of available apps. This implements the rcl_provider behaviour.
+-module(rcl_rel_discovery).
+
+-export([do/3,
+         format_error/1]).
+
+-include_lib("relcool/include/relcool.hrl").
+
+%%============================================================================
+%% API
+%%============================================================================
+
+%% @doc recursively dig down into the library directories specified in the state
+%% looking for OTP Applications
+-spec do(rcl_state:t(), [filename:name()], [rcl_app_info:t()]) ->
+                {ok, [rcl_release:t()]} | relcool:error().
+do(State, LibDirs, AppMeta) ->
+    rcl_log:info(rcl_state:log(State),
+                 fun() ->
+                         ["Resolving available releases from directories:\n",
+                          [[rcl_util:indent(1), LibDir, "\n"] || LibDir <- LibDirs]]
+                 end),
+    resolve_rel_metadata(State, LibDirs, AppMeta).
+
+-spec format_error([ErrorDetail::term()]) -> iolist().
+format_error(ErrorDetails)
+  when erlang:is_list(ErrorDetails) ->
+    [[format_detail(ErrorDetail), "\n"] || ErrorDetail <- ErrorDetails].
+
+%%%===================================================================
+%%% Internal Functions
+%%%===================================================================
+resolve_rel_metadata(State, LibDirs, AppMeta) ->
+    ReleaseMeta0 =
+        lists:flatten(ec_plists:map(fun(LibDir) ->
+                                            discover_dir([], LibDir, AppMeta)
+                                    end, LibDirs)),
+    Errors = [case El of
+                  {error, Ret} -> Ret;
+                  _ -> El
+              end
+              || El <- ReleaseMeta0,
+                 case El of
+                     {error, _} ->
+                         true;
+                     _ ->
+                         false
+                 end],
+
+    case Errors of
+        [] ->
+            ReleaseMeta1 = lists:flatten(ReleaseMeta0),
+            rcl_log:debug(rcl_state:log(State),
+                          fun() ->
+                                  ["Resolved the following OTP Releases from the system: \n",
+                                   [[rcl_release:format(1, Rel), "\n"] || Rel <- ReleaseMeta1]]
+                          end),
+            {ok, ReleaseMeta1};
+        _ ->
+            ?RCL_ERROR(Errors)
+    end.
+
+-spec format_detail(ErrorDetail::term()) -> iolist().
+format_detail({accessing, File, eaccess}) ->
+    io_lib:format("permission denied accessing file ~s", [File]);
+format_detail({accessing, File, Type}) ->
+    io_lib:format("error (~p) accessing file ~s", [Type, File]).
+
+-spec discover_dir([file:name()], file:name(), [rcl_app_info:t()]) ->
+        [rcl_release:t() | {error, Reason::term()}]
+      | rcl_release:t()
+      | {error, Reason::term()}.
+discover_dir(IgnoreDirs, File, AppMeta) ->
+    case (not lists:member(File, IgnoreDirs))
+        andalso filelib:is_dir(File) of
+        true ->
+            case file:list_dir(File) of
+                {error, Reason} ->
+                    {error, {accessing, File, Reason}};
+                {ok, List} ->
+                    ec_plists:map(fun(LibDir) ->
+                                          discover_dir(IgnoreDirs, LibDir, AppMeta)
+                                  end,
+                                 [filename:join([File, Dir]) || Dir <- List])
+            end;
+        false ->
+            is_valid_release(File, AppMeta)
+    end.
+
+-spec is_valid_release(file:name(),
+                       [rcl_app_info:t()]) ->
+        rcl_release:t()
+      | {error, Reason::term()}
+      | [].
+is_valid_release(File, AppMeta) ->
+    case lists:suffix(".rel", File) of
+        true ->
+            resolve_release(File, AppMeta);
+        false ->
+            []
+    end.
+
+resolve_release(RelFile, AppMeta) ->
+    case file:consult(RelFile) of
+        {ok, [{release, {RelName, RelVsn},
+               {erts, ErtsVsn},
+               Apps}]} ->
+            build_release(RelName, RelVsn, ErtsVsn, Apps, AppMeta);
+        {ok, InvalidRelease} ->
+            ?RCL_ERROR({invalid_release_information, InvalidRelease});
+        {error, Reason} ->
+            ?RCL_ERROR({unable_to_read, RelFile, Reason})
+    end.
+
+build_release(RelName, RelVsn, ErtsVsn, Apps, AppMeta) ->
+    Release = rcl_release:erts(rcl_release:new(RelName, RelVsn),
+                               ErtsVsn),
+    resolve_apps(Apps, AppMeta, Release, []).
+
+resolve_apps([], _AppMeta, Release, Acc) ->
+    rcl_release:application_details(Release, Acc);
+resolve_apps([AppInfo | Apps], AppMeta, Release, Acc) ->
+    AppName = erlang:element(1, AppInfo),
+    AppVsn = erlang:element(2, AppInfo),
+    case find_app(AppName, AppVsn, AppMeta) of
+        Error = {error, _} ->
+            Error;
+        ResolvedApp ->
+            resolve_apps(Apps, AppMeta, Release, [ResolvedApp | Acc])
+    end.
+
+find_app(AppName, AppVsn, AppMeta) ->
+    case ec_lists:find(fun(App) ->
+                               NAppName = rcl_app:name(App),
+                               NAppVsn = rcl_app:version(App),
+                               AppName == NAppName andalso
+                                   AppVsn == NAppVsn
+                       end, AppMeta) of
+        {ok, Head} ->
+            Head;
+        error ->
+            ?RCL_ERROR({could_not_find, {AppName, AppVsn}})
+    end.