Move all RabbitMQ-specific environment variables to `rabbit_env`

The reading of `$NOTIFY_SOCKET` is also moved at the same time. This is
in preparation of the work around start/stop status.

There is an associated commit in rabbitmq-common to update `rabbit_env`
and record the origin of each variable.

[#170149339]

4 files changed, 28 insertions, 29 deletions

diff --git a/src/rabbit.erl b/src/rabbit.erl
index 0bf6d47700..41a54ba36c 100644
--- a/src/rabbit.erl
+++ b/src/rabbit.erl
@@ -386,10 +386,9 @@ maybe_sd_notify() ->
     end.
 
 sd_notify_ready() ->
-    case {os:type(), os:getenv("NOTIFY_SOCKET")} of
-        {{win32, _}, _} ->
-            true;
-        {_, [_|_]} -> %% Non-empty NOTIFY_SOCKET, give it a try
+    case rabbit_prelaunch:get_context() of
+        #{systemd_notify_socket := Socket} when Socket =/= undefined ->
+            %% Non-empty NOTIFY_SOCKET, give it a try
             sd_notify_legacy() orelse sd_notify_socat();
         _ ->
             true
@@ -432,9 +431,11 @@ socat_socket_arg(UnixSocket) ->
     "unix-sendto:" ++ UnixSocket.
 
 sd_open_port() ->
+    #{systemd_notify_socket := Socket} = rabbit_prelaunch:get_context(),
+    true = Socket =/= undefined,
     open_port(
       {spawn_executable, os:find_executable("socat")},
-      [{args, [socat_socket_arg(os:getenv("NOTIFY_SOCKET")), "STDIO"]},
+      [{args, [socat_socket_arg(Socket), "STDIO"]},
        use_stdio, out]).
 
 sd_notify_socat(Unit) ->
diff --git a/src/rabbit_feature_flags.erl b/src/rabbit_feature_flags.erl
index 054bc90a0b..9be78eec13 100644
--- a/src/rabbit_feature_flags.erl
+++ b/src/rabbit_feature_flags.erl
@@ -1246,22 +1246,17 @@ regen_registry_mod(AllFeatureFlags,
             {error, {compilation_failure, Errors, Warnings}}
     end.
 
--ifdef(TEST).
 maybe_log_registry_source_code(Forms) ->
-    case os:getenv("LOG_FF_REGISTRY") of
-        false ->
-            ok;
-        _ ->
+    case rabbit_prelaunch:get_context() of
+        #{log_feature_flags_registry := true} ->
             rabbit_log_feature_flags:debug(
               "== FEATURE FLAGS REGISTRY ==~n"
               "~s~n"
               "== END ==~n",
-              [erl_prettypr:format(erl_syntax:form_list(Forms))])
+              [erl_prettypr:format(erl_syntax:form_list(Forms))]);
+        _ ->
+            ok
     end.
--else.
-maybe_log_registry_source_code(_) ->
-    ok.
--endif.
 
 -spec load_registry_mod(atom(), binary()) ->
     ok | {error, any()} | no_return().
@@ -2003,7 +1998,7 @@ sync_feature_flags_with_cluster([], NodeIsVirgin, _) ->
                               "Feature flags: starting an unclustered "
                               "node for the first time: all feature "
                               "flags are forcibly left disabled from "
-                              "the RABBITMQ_FEATURE_FLAGS environment "
+                              "the $RABBITMQ_FEATURE_FLAGS environment "
                               "variable"),
                             ok;
                         _ ->
@@ -2011,7 +2006,7 @@ sync_feature_flags_with_cluster([], NodeIsVirgin, _) ->
                               "Feature flags: starting an unclustered "
                               "node for the first time: only the "
                               "following feature flags specified in "
-                              "the RABBITMQ_FEATURE_FLAGS environment "
+                              "the $RABBITMQ_FEATURE_FLAGS environment "
                               "variable will be enabled: ~p",
                               [FeatureNames]),
                             enable(FeatureNames)
@@ -2126,9 +2121,12 @@ get_forced_feature_flag_names() ->
 %% @private
 
 get_forced_feature_flag_names_from_env() ->
-    case os:getenv("RABBITMQ_FEATURE_FLAGS") of
-        false -> undefined;
-        Value -> [list_to_atom(V) ||V <- string:lexemes(Value, ",")]
+    case rabbit_prelaunch:get_context() of
+        #{forced_feature_flags_on_init := ForcedFFs}
+          when is_list(ForcedFFs) ->
+            ForcedFFs;
+        _ ->
+            undefined
     end.
 
 -spec get_forced_feature_flag_names_from_config() -> [feature_name()] | undefined.
diff --git a/src/rabbit_lager.erl b/src/rabbit_lager.erl
index e9dce91909..a5c591b1ce 100644
--- a/src/rabbit_lager.erl
+++ b/src/rabbit_lager.erl
@@ -299,7 +299,7 @@ configure_lager() ->
     end,
     LogLevelsFromContext = case rabbit_prelaunch:get_context() of
                                #{log_levels := LL} -> LL;
-                               undefined           -> undefined
+                               _                   -> undefined
                            end,
     Fun = fun
               (global, _, CC) ->
@@ -473,12 +473,14 @@ prepare_rabbit_log_config() ->
         tty ->
             set_env_default_log_console();
         FileName when is_list(FileName) ->
-            case os:getenv("RABBITMQ_LOGS_source") of
+            case rabbit_prelaunch:get_context() of
                 %% The user explicitly sets $RABBITMQ_LOGS;
                 %% we should override a file location even
                 %% if it's set in rabbitmq.config
-                "environment" -> set_env_default_log_file(FileName, override);
-                _             -> set_env_default_log_file(FileName, keep)
+                #{var_origins := #{main_log_file := environment}} ->
+                    set_env_default_log_file(FileName, override);
+                _ ->
+                    set_env_default_log_file(FileName, keep)
             end
     end,
 
@@ -551,7 +553,7 @@ set_env_upgrade_log_file(FileName) ->
 generate_lager_sinks(SinkNames, SinkConfigs) ->
     LogLevels = case rabbit_prelaunch:get_context() of
                     #{log_levels := LL} -> LL;
-                    undefined           -> undefined
+                    _                   -> undefined
                 end,
     DefaultLogLevel = case LogLevels of
                           #{global := LogLevel} ->
diff --git a/src/rabbit_nodes.erl b/src/rabbit_nodes.erl
index eb582c69f5..af0a546db5 100644
--- a/src/rabbit_nodes.erl
+++ b/src/rabbit_nodes.erl
@@ -41,10 +41,8 @@ boot() ->
   seed_user_provided_cluster_name().
 
 name_type() ->
-    case os:getenv("RABBITMQ_USE_LONGNAME") of
-        "true" -> longnames;
-        _      -> shortnames
-    end.
+    #{nodename_type := NodeType} = rabbit_prelaunch:get_context(),
+    NodeType.
 
 -spec names(string()) ->
           rabbit_types:ok_or_error2([{string(), integer()}], term()).