Separate erlang config file for reloadable parameters

7 files changed, 110 insertions, 7 deletions

diff --git a/src/http_auth.erl b/src/http_auth.erl
index 16d7dfa..3bd18b1 100644
--- a/src/http_auth.erl
+++ b/src/http_auth.erl
@@ -20,7 +20,7 @@ read_key_table() ->
     lists:foreach(
       fun ({KeyName, Der}) ->
               true = ets:insert(?KEY_TABLE, {KeyName, sign:pem_entry_decode({'SubjectPublicKeyInfo', Der, []})})
-      end, application:get_env(plop, apikeys, [])),
+      end, plopconfig:get_env(apikeys, [])),
     case application:get_env(plop, own_key, none) of
         {_OwnKeyName, OwnKeyFile} ->
             OwnKey = sign:read_keyfile_ec(OwnKeyFile),
@@ -72,7 +72,7 @@ check_acl(Method, KeyName, Path) ->
                      _ ->
                          allowed_clients
                  end,
-    ACL = application:get_env(plop, EnvVarName, []),
+    ACL = plopconfig:get_env(EnvVarName, []),
     lager:debug("ACL: ~p", [ACL]),
     case lists:keyfind(Path, 1, ACL) of
         {_, noauth} ->
diff --git a/src/plop.erl b/src/plop.erl
index 4ad0b98..fcc964b 100644
--- a/src/plop.erl
+++ b/src/plop.erl
@@ -210,10 +210,10 @@ testing_get_pubkey() ->
     sign:get_pubkey().
 
 storage_nodes() ->
-    application:get_env(plop, storage_nodes, []).
+    plopconfig:get_env(storage_nodes, []).
 
 storage_nodes_quorum() ->
-    {ok, Value} = application:get_env(plop, storage_nodes_quorum),
+    {ok, Value} = plopconfig:get_env(storage_nodes_quorum),
     Value.
 
 send_http_request(TreeLeafHash, URL, Headers, RequestBody) ->
diff --git a/src/plop_app.erl b/src/plop_app.erl
index 12f52ee..c51e6e4 100644
--- a/src/plop_app.erl
+++ b/src/plop_app.erl
@@ -7,6 +7,7 @@
 
 start(normal, Args) ->
     hackney:start(),
+    plopconfig:init_table(),
     http_auth:init_key_table(),
     plop:initsize(),
     perm:init_module(),
diff --git a/src/plop_sup.erl b/src/plop_sup.erl
index 55d6e9a..6bac20e 100644
--- a/src/plop_sup.erl
+++ b/src/plop_sup.erl
@@ -48,7 +48,8 @@ init([]) ->
                                    ]),
     Children = [permanent_worker(the_db, {db, start_link, []}, [db]),
                 permanent_worker(the_storagedb, {storagedb, start_link, []}),
-                permanent_worker(fsync, {fsyncport, start_link, []})],
+                permanent_worker(fsync, {fsyncport, start_link, []}),
+                permanent_worker(plopcontrol, {plopcontrol, start_link, []})],
     OptionalChildren = lists:map(fun (ServiceName) ->
                                          case ServiceName of
                                              ht ->
diff --git a/src/plopconfig.erl b/src/plopconfig.erl
new file mode 100644
index 0000000..00b29df
--- /dev/null
+++ b/src/plopconfig.erl
@@ -0,0 +1,57 @@
+%%% Copyright (c) 2017, NORDUnet A/S.
+%%% See LICENSE for licensing information.
+
+-module(plopconfig).
+-export([get_env/1, get_env/2, init_table/0, load_config/0]).
+
+-define(PLOPCONFIG_TABLE, plopconfig).
+
+init_table() ->
+    case ets:info(?PLOPCONFIG_TABLE) of
+	undefined ->
+	    ok;
+	_ ->
+	    ets:delete(?PLOPCONFIG_TABLE)
+    end,
+    ets:new(?PLOPCONFIG_TABLE, [set, public, named_table]),
+    load_config().
+
+keys() ->
+    KeyList = lists:map(fun ({Key, _Value}) -> Key end,
+                        ets:tab2list(?PLOPCONFIG_TABLE)),
+    sets:from_list(KeyList).
+
+load_config() ->
+    {ok, Filename} = application:get_env(plop, plopconfig),
+    {ok, File} = file:consult(Filename),
+    OldKeys = keys(),
+    lists:foreach(
+      fun ({Key, Value}) ->
+              true = ets:insert(?PLOPCONFIG_TABLE, {Key, Value})
+      end, hd(File)),
+    NewKeys = keys(),
+    RemovedKeys = sets:subtract(OldKeys, NewKeys),
+    lists:foreach(fun (Key) ->
+                          ets:delete(?PLOPCONFIG_TABLE, Key)
+                  end, sets:to_list(RemovedKeys)),
+    lager:info("loaded config: new keys ~p old keys ~p removed keys ~p",
+               [sets:to_list(NewKeys),
+                sets:to_list(OldKeys),
+                sets:to_list(RemovedKeys)]),
+    ok.
+
+get_env(Key, DefaultValue) ->
+    case get_env(Key) of
+        {ok, Value} ->
+            Value;
+        _ ->
+            DefaultValue
+    end.
+
+get_env(Key) ->
+    case ets:lookup(?PLOPCONFIG_TABLE, Key) of
+        [{_, Value}] ->
+            {ok, Value};
+        [] ->
+            undefined
+    end.
diff --git a/src/plopcontrol.erl b/src/plopcontrol.erl
new file mode 100644
index 0000000..de7faba
--- /dev/null
+++ b/src/plopcontrol.erl
@@ -0,0 +1,44 @@
+%%% Copyright (c) 2017, NORDUnet A/S.
+%%% See LICENSE for licensing information.
+
+-module(plopcontrol).
+-export([start_link/0, server_start/2]).
+
+start_link() ->
+    case gen_tcp:listen(application:get_env(plop, plopcontrolport, 0), [binary, {packet, line},
+                                                                        {active, false},
+                                                                        {ip, {127, 0, 0, 1}}]) of
+        {ok, ListenSocket} ->
+            proc_lib:start_link(?MODULE,server_start,[self(), ListenSocket]);
+        {error,Reason} ->
+            {error,Reason}
+    end.
+
+server_start(Parent, ListenSocket) ->
+    proc_lib:init_ack(Parent, {ok, self()}),
+    {ok, Port} = inet:port(ListenSocket),
+    {ok, PlopcontrolFile} = application:get_env(plop, plopcontrol),
+    atomic:replacefile(PlopcontrolFile, integer_to_list(Port)),
+    acceptloop(ListenSocket).
+
+acceptloop(ListenSocket) ->
+    {ok, Socket} = gen_tcp:accept(ListenSocket),
+    commandloop(Socket),
+    acceptloop(ListenSocket).
+
+commandloop(Socket) ->
+    case gen_tcp:recv(Socket, 0) of
+        {ok, Packet} ->
+            Answer = command(Packet),
+            gen_tcp:send(Socket, Answer),
+            commandloop(Socket);
+        {error, _Reason} ->
+            ok
+    end.
+
+command(<<"reload\n">>) ->
+    plopconfig:load_config(),
+    "reload completed\n";
+
+command(_) ->
+    "unknown command\n".
diff --git a/src/sign.erl b/src/sign.erl
index 99b83e6..6e0e0bd 100644
--- a/src/sign.erl
+++ b/src/sign.erl
@@ -151,7 +151,7 @@ remote_sign_request([URL|RestURLs], Request) ->
 sign_sct(Data = <<_Version:8,
                   ?CERTIFICATE_TIMESTAMP:8,
                   _/binary>>) ->
-    case application:get_env(plop, signing_nodes) of
+    case plopconfig:get_env(signing_nodes) of
         {ok, URLBases} ->
             Request = {[{plop_version, 1},
                         {data, base64:encode(Data)}
@@ -164,7 +164,7 @@ sign_sct(Data = <<_Version:8,
 sign_sth(Data = <<_Version:8,
                   ?TREE_HASH:8,
                   _/binary>>) ->
-    case application:get_env(plop, signing_nodes) of
+    case plopconfig:get_env(signing_nodes) of
         {ok, URLBases} ->
             Request = {[{plop_version, 1},
                         {data, base64:encode(Data)}