rabbit_peer_discovery: Fixes and improvements for Consul and etcd

deps/rabbit/src/rabbit_db.erl

@@ -52,6 +52,7 @@ init() ->
 
     ensure_dir_exists(),
     rabbit_peer_discovery:maybe_init(),
+    rabbit_peer_discovery:maybe_register(),
 
     pre_init(IsVirgin),
 
@@ -77,7 +78,6 @@ init() ->
                "DB: initialization successeful",
                #{domain => ?RMQLOG_DOMAIN_DB}),
 
-            rabbit_peer_discovery:maybe_register(),
             init_finished(),
 
             ok;

deps/rabbit/src/rabbit_peer_discovery.erl

@@ -186,8 +186,22 @@ sync_desired_cluster(Backend, RetriesLeft, RetryDelay) ->
                #{domain => ?RMQLOG_DOMAIN_PEER_DISC}),
             ok;
         {ok, {DiscoveredNodes, NodeType}} ->
-            NodesAndProps = query_node_props(DiscoveredNodes),
-            case can_use_discovered_nodes(DiscoveredNodes, NodesAndProps) of
+            NodeAlreadySelected = is_atom(DiscoveredNodes),
+            NodesAndProps = case NodeAlreadySelected of
+                                true ->
+                                    ?LOG_DEBUG(
+                                       "Peer discovery: node '~ts' already "
+                                       "selected by backend",
+                                       [DiscoveredNodes],
+                                       #{domain => ?RMQLOG_DOMAIN_PEER_DISC}),
+                                    query_node_props([DiscoveredNodes]);
+                                false ->
+                                    query_node_props(DiscoveredNodes)
+                            end,
+            CanUse = (
+              NodeAlreadySelected orelse
+              can_use_discovered_nodes(DiscoveredNodes, NodesAndProps)),
+            case CanUse of
                 true ->
                     case select_node_to_join(NodesAndProps) of
                         SelectedNode when SelectedNode =/= false ->
@@ -249,8 +263,9 @@ retry_sync_desired_cluster(_Backend, 0, _RetryDelay) ->
     ok.
 
 -spec discover_cluster_nodes() -> {ok, Discovery} when
-      Discovery :: {DiscoveredNodes, NodeType},
+      Discovery :: {DiscoveredNodes | SelectedNode, NodeType},
       DiscoveredNodes :: [node()],
+      SelectedNode :: node(),
       NodeType :: rabbit_types:node_type().
 %% @doc Queries the peer discovery backend to discover nodes.
 %%
@@ -262,10 +277,11 @@ discover_cluster_nodes() ->
 
 -spec discover_cluster_nodes(Backend) -> Ret when
       Backend :: backend(),
-      Discovery :: {DiscoveredNodes, NodeType},
+      Ret :: {ok, Discovery} | {error, Reason},
+      Discovery :: {DiscoveredNodes | SelectedNode, NodeType},
       DiscoveredNodes :: [node()],
+      SelectedNode :: node(),
       NodeType :: rabbit_types:node_type(),
-      Ret :: {ok, Discovery} | {error, Reason},
       Reason :: any().
 %% @private
 
@@ -295,7 +311,7 @@ discover_cluster_nodes(Backend) ->
 
 -spec check_discovered_nodes_list_validity(DiscoveredNodes, NodeType) ->
     Ret when
-      DiscoveredNodes :: [node()],
+      DiscoveredNodes :: [node()] | node(),
       NodeType :: rabbit_types:node_type(),
       Ret :: ok.
 %% @private
@@ -310,6 +326,12 @@ check_discovered_nodes_list_validity(DiscoveredNodes, NodeType)
         [] -> ok;
         _  -> e({invalid_cluster_node_names, BadNodenames})
     end;
+check_discovered_nodes_list_validity(SelectedNode, NodeType)
+  when NodeType =:= disc orelse NodeType =:= disk orelse NodeType =:= ram ->
+    case is_atom(SelectedNode) of
+        true  -> ok;
+        false -> e({invalid_cluster_node_names, SelectedNode})
+    end;
 check_discovered_nodes_list_validity(DiscoveredNodes, BadNodeType)
   when is_list(DiscoveredNodes) ->
     e({invalid_cluster_node_type, BadNodeType}).
@@ -836,7 +858,7 @@ can_use_discovered_nodes(_DiscoveredNodes, []) ->
     false.
 
 -spec select_node_to_join(NodesAndProps) -> SelectedNode when
-      NodesAndProps :: [node_and_props()],
+      NodesAndProps :: nonempty_list(node_and_props()),
       SelectedNode :: node() | false.
 %% @doc Selects the node to join among the sorted list of nodes.
 %%
@@ -1140,10 +1162,10 @@ unlock(Backend, Data) ->
                 {Nodes :: [node()],
                  NodeType :: rabbit_types:node_type()} |
                 {ok, Nodes :: [node()]} |
-                {ok, {Nodes :: [node()],
+                {ok, {Nodes :: [node()] | node(),
                       NodeType :: rabbit_types:node_type()}} |
                 {error, Reason :: string()}) ->
-    {ok, {Nodes :: [node()], NodeType :: rabbit_types:node_type()}} |
+    {ok, {Nodes :: [node()] | node(), NodeType :: rabbit_types:node_type()}} |
     {error, Reason :: string()}.
 
 normalize(Nodes) when is_list(Nodes) ->
@@ -1154,6 +1176,9 @@ normalize({ok, Nodes}) when is_list(Nodes) ->
   {ok, {Nodes, disc}};
 normalize({ok, {Nodes, NodeType}}) when is_list(Nodes) andalso is_atom(NodeType) ->
   {ok, {Nodes, NodeType}};
+normalize({ok, {Node, NodeType}})
+  when is_atom(Node) andalso is_atom(NodeType) ->
+  {ok, {Node, NodeType}};
 normalize({error, Reason}) ->
   {error, Reason}.
 

deps/rabbit_common/src/rabbit_peer_discovery_backend.erl

@@ -41,7 +41,7 @@
 
 -callback init() -> ok | {error, Reason :: string()}.
 
--callback list_nodes() -> {ok, {Nodes :: list(), NodeType :: rabbit_types:node_type()}} |
+-callback list_nodes() -> {ok, {Nodes :: [node()] | node(), NodeType :: rabbit_types:node_type()}} |
                           {error, Reason :: string()}.
 
 -callback supports_registration() -> boolean().
@@ -57,3 +57,8 @@
 -callback unlock(Data :: term()) -> ok.
 
 -optional_callbacks([init/0]).
+
+-export([api_version/0]).
+
+api_version() ->
+    2.

deps/rabbitmq_ct_helpers/src/rabbit_ct_helpers.erl

@@ -880,7 +880,10 @@ exec([Cmd | Args], Options) when is_list(Cmd) orelse is_binary(Cmd) ->
             Env1 = [
               begin
                   Key1 = format_arg(Key),
-                  Value1 = format_arg(Value),
+                  Value1 = case Value of
+                               false -> false;
+                               _     -> format_arg(Value)
+                           end,
                   Value2 = case is_binary(Value1) of
                                true  -> binary_to_list(Value1);
                                false -> Value1
@@ -894,8 +897,10 @@ exec([Cmd | Args], Options) when is_list(Cmd) orelse is_binary(Cmd) ->
                | proplists:delete(env, PortOptions1)],
               Log ++ "~n~nEnvironment variables:~n" ++
               string:join(
-                [rabbit_misc:format("  ~ts=~ts", [K, string:replace(V, "~", "~~", all)])
-                 || {K, V} <- Env1],
+                [rabbit_misc:format(
+                   "  ~ts=~ts",
+                   [K, string:replace(V, "~", "~~", all)])
+                 || {K, V} <- Env1, is_list(V) ],
                 "~n")
             }
     end,

deps/rabbitmq_peer_discovery_consul/BUILD.bazel

@@ -79,6 +79,11 @@ rabbitmq_integration_suite(
     name = "config_schema_SUITE",
 )
 
+rabbitmq_integration_suite(
+    name = "system_SUITE",
+    size = "large",
+)
+
 rabbitmq_suite(
     name = "rabbitmq_peer_discovery_consul_SUITE",
     size = "medium",

deps/rabbitmq_peer_discovery_consul/app.bzl

@@ -99,6 +99,15 @@ def test_suite_beam_files(name = "test_suite_beam_files"):
         app_name = "rabbitmq_peer_discovery_consul",
         erlc_opts = "//:test_erlc_opts",
     )
+    erlang_bytecode(
+        name = "system_SUITE_beam_files",
+        testonly = True,
+        srcs = ["test/system_SUITE.erl"],
+        outs = ["test/system_SUITE.beam"],
+        hdrs = [],
+        app_name = "rabbitmq_peer_discovery_consul",
+        erlc_opts = "//:test_erlc_opts",
+    )
     erlang_bytecode(
         name = "rabbitmq_peer_discovery_consul_SUITE_beam_files",
         testonly = True,

deps/rabbitmq_peer_discovery_consul/include/rabbit_peer_discovery_consul.hrl

@@ -69,6 +69,11 @@
                                                    env_variable  = "CONSUL_SVC_ADDR_NODENAME",
                                                    default_value = false
                                                   },
+          consul_svc_id                      => #peer_discovery_config_entry_meta{
+                                                   type          = string,
+                                                   env_variable  = "CONSUL_SVC_ID",
+                                                   default_value = "undefined"
+                                                  },
           consul_svc_port                    => #peer_discovery_config_entry_meta{
                                                    type          = integer,
                                                    env_variable  = "CONSUL_SVC_PORT",

deps/rabbitmq_peer_discovery_consul/priv/schema/rabbitmq_peer_discovery_consul.schema

@@ -140,7 +140,7 @@ fun(Conf) ->
 end}.
 
 
-%% use (Erlang) node name when compuing service address?
+%% use (Erlang) node name when computing service address?
 
 {mapping, "cluster_formation.consul.svc_addr_use_nodename", "rabbit.cluster_formation.peer_discovery_consul.consul_svc_addr_nodename", [
     {datatype, {enum, [true, false]}}
@@ -155,6 +155,21 @@ fun(Conf) ->
 end}.
 
 
+%% service ID
+
+{mapping, "cluster_formation.consul.svc_id", "rabbit.cluster_formation.peer_discovery_consul.consul_svc_id", [
+    {datatype, string}
+]}.
+
+{translation, "rabbit.cluster_formation.peer_discovery_consul.consul_svc_id",
+fun(Conf) ->
+    case cuttlefish:conf_get("cluster_formation.consul.svc_id", Conf, undefined) of
+        undefined -> cuttlefish:unset();
+        Value     -> Value
+    end
+end}.
+
+
 %% (optionally) append a suffix to node names retrieved from Consul
 
 {mapping, "cluster_formation.consul.domain_suffix", "rabbit.cluster_formation.peer_discovery_consul.consul_domain", [