Get rid of app.config

app.config has been a long standing erroneous file in rebar. Erlang/OTP
documentation suggests a sys.config file instead. This file is stored in
the releases/VSN directory. This does a few things but most importantly
it ensures your config (contained in the application environment)
survives a hot upgrade. It also has the advantage of allowing the
configuration of the application to be versioned along side the
application code. This patch flips rebar to use sys.config rather than
app.config.

Additionally it makes this flip to vm.args as well, making them
versioned just like sys.config.

This patch also includes runner script changes to support the old
etc/app.config config file location and support for Windows.

Thanks to mokele for the initial work and kick in the pants to make this
finially happen.

priv/templates/simplenode.reltool.config

@@ -13,8 +13,15 @@
         ]},
        {boot_rel, "{{nodeid}}"},
        {profile, embedded},
+       {excl_archive_filters, [".*"]}, %% Do not archive built libs
        {excl_sys_filters, ["^bin/.*",
                            "^erts.*/bin/(dialyzer|typer)"]},
+
+       %% Including HiPE can cause issues generating your first upgrade.
+       %% If you plan to distribute HiPE in your release remove the
+       %% following line.
+       {app, hipe, [{incl_cond, exclude}]},
+
        {app, sasl, [{incl_cond, include}]}
       ]}.
 
@@ -25,8 +32,8 @@
            {copy, "files/erl", "\{\{erts_vsn\}\}/bin/erl"},
            {copy, "files/nodetool", "\{\{erts_vsn\}\}/bin/nodetool"},
            {copy, "files/{{nodeid}}", "bin/{{nodeid}}"},
+           {copy, "files/sys.config", "releases/\{\{rel_vsn\}\}/sys.config"},
            {copy, "files/{{nodeid}}.cmd", "bin/{{nodeid}}.cmd"},
            {copy, "files/start_erl.cmd", "bin/start_erl.cmd"},
-           {copy, "files/app.config", "etc/app.config"},
-           {copy, "files/vm.args", "etc/vm.args"}
+           {copy, "files/vm.args", "releases/\{\{rel_vsn\}\}/vm.args"}
           ]}.

priv/templates/simplenode.runner

@@ -50,6 +50,20 @@ ERTS_PATH=$RUNNER_BASE_DIR/erts-$ERTS_VSN/bin
 # Setup command to control the node
 NODETOOL="$ERTS_PATH/escript $ERTS_PATH/nodetool $NAME_ARG $COOKIE_ARG"
 
+# Use releases/VSN/sys.config if it exists otherwise use etc/app.config
+if [ -e "$RUNNER_BASE_DIR/releases/$APP_VSN/sys.config" ]; then
+    CONFIG_PATH="$RUNNER_BASE_DIR/releases/$APP_VSN/sys.config"
+else
+    CONFIG_PATH="$RUNNER_ETC_DIR/app.config"
+fi
+
+# Use releases/VSN/vm.args if it exists otherwise use etc/vm.args
+if [-e "$RUNNER_BASE_DIR/releases/$APP_VSN/vm.args" ]; then
+    VMARGS_PATH="$RUNNER_BASE_DIR/releases/$APP_VSN/vm.args"
+else
+    VMARGS_PATH="$RUNNER_ETC_DIR/vm.args"
+fi
+
 # Check the first argument for instructions
 case "$1" in
     start)
@@ -147,7 +161,7 @@ case "$1" in
         BINDIR=$ROOTDIR/erts-$ERTS_VSN/bin
         EMU=beam
         PROGNAME=`echo $0 | sed 's/.*\\///'`
-        CMD="$BINDIR/erlexec -boot $RUNNER_BASE_DIR/releases/$APP_VSN/$BOOTFILE -mode embedded -config $RUNNER_ETC_DIR/app.config -args_file $RUNNER_ETC_DIR/vm.args -- ${1+"$@"}"
+        CMD="$BINDIR/erlexec -boot $RUNNER_BASE_DIR/releases/$APP_VSN/$BOOTFILE -mode embedded -config $CONFIG_PATH -args_file $VMARGS_PATH -- ${1+"$@"}"
         export EMU
         export ROOTDIR
         export BINDIR

priv/templates/simplenode.template

@@ -6,7 +6,7 @@
 {chmod, 8#744, "files/nodetool"}.
 {file, "simplenode.runner", "files/{{nodeid}}"}.
 {chmod, 8#744, "files/{{nodeid}}"}.
-{file, "simplenode.app.config", "files/app.config"}.
+{file, "simplenode.sys.config", "files/sys.config"}.
 {template, "simplenode.vm.args", "files/vm.args"}.
 {template, "simplenode.windows.runner.cmd", "files/{{nodeid}}.cmd"}.
 {file, "simplenode.windows.start_erl.cmd", "files/start_erl.cmd"}.

priv/templates/simplenode.windows.start_erl.cmd

@@ -19,8 +19,18 @@
 
 @set erl_exe=%node_root%\erts-%erts_version%\bin\erl.exe
 @set boot_file=%releases_dir%\%release_version%\%node_name%
-@set app_config=%node_root%\etc\app.config
-@set vm_args=%node_root%\etc\vm.args
+
+@if exist %releases_dir%\%release_version%\sys.config (
+    @set app_config=%releases_dir%\%release_version%\sys.config
+) @else (
+    @set app_config=%node_root%\etc\app.config
+)
+
+@if exist %releases_dir%\%release_version%\vm.args (
+    @set vm_args=%releases_dir%\%release_version%\vm.args
+) @else (
+    @set vm_args=%node_root%\etc\vm.args
+)
 
 @%erl_exe% %erl_args% -boot %boot_file% -config %app_config% -args_file %vm_args%
 

src/rebar_rel_utils.erl

@@ -55,11 +55,16 @@ is_rel_dir(Dir) ->
     end.
 
 %% Get release name and version from a reltool.config
-get_reltool_release_info(ReltoolConfig) ->
-    %% expect the first rel in the proplist to be the one you want
-    {sys, Config} = get_sys_tuple(ReltoolConfig),
+get_reltool_release_info([{sys, Config}| _]) ->
     {rel, Name, Ver, _} = proplists:lookup(rel, Config),
-    {Name, Ver}.
+    {Name, Ver};
+get_reltool_release_info(ReltoolFile) when is_list(ReltoolFile) ->
+    case file:consult(ReltoolFile) of
+        {ok, ReltoolConfig} ->
+            get_reltool_release_info(ReltoolConfig);
+        _ ->
+            ?ABORT("Failed to parse ~s~n", [ReltoolFile])
+    end.
 
 %% Get release name and version from a rel file
 get_rel_release_info(RelFile) ->
@@ -170,4 +175,4 @@ make_proplist([H|T], Acc) ->
      Ver = element(2, H),
      make_proplist(T, [{App,Ver}|Acc]);
 make_proplist([], Acc) ->
-     Acc.
+     Acc.

src/rebar_reltool.erl

@@ -173,10 +173,17 @@ run_reltool(Server, _Config, ReltoolConfig) ->
                            [Reason])
             end,
 
+            {BootRelName, BootRelVsn} = 
+                rebar_rel_utils:get_reltool_release_info(ReltoolConfig),
+
+            ok = create_RELEASES(TargetDir, BootRelName, BootRelVsn),
+
             %% Initialize overlay vars with some basics
             %% (that can get overwritten)
-            OverlayVars0 = dict:from_list([{erts_vsn, "erts-" ++ erlang:system_info(version)},
-                                           {target_dir, TargetDir}]),
+            OverlayVars0 = 
+                dict:from_list([{erts_vsn, "erts-" ++ erlang:system_info(version)},
+                                {rel_vsn, BootRelVsn},
+                                {target_dir, TargetDir}]),
 
             %% Load up any variables specified by overlay_vars
             OverlayVars1 = overlay_vars(OverlayVars0, ReltoolConfig),
@@ -312,3 +319,15 @@ execute_overlay([Other | _Rest], _Vars, _BaseDir, _TargetDir) ->
 apply_file_info(InFile, OutFile) ->
     {ok, FileInfo} = file:read_file_info(InFile),
     ok = file:write_file_info(OutFile, FileInfo).
+
+create_RELEASES(TargetDir, RelName, RelVsn) ->
+    ReleasesDir = filename:join(TargetDir, "releases"),
+    case release_handler:create_RELEASES(TargetDir, ReleasesDir,
+              filename:join([ReleasesDir, RelVsn, RelName ++ ".rel"]),
+              filename:join(TargetDir, "lib")) of
+        ok ->
+            ok;
+        {error, Reason} ->
+            ?ABORT("Failed to create RELEASES file: ~p\n",
+                   [Reason])
+    end.

src/rebar_upgrade.erl

@@ -32,6 +32,8 @@
 
 -export(['generate-upgrade'/2]).
 
+-define(TMP, "_tmp").
+
 %% ====================================================================
 %% Public API
 %% ====================================================================
@@ -141,22 +143,21 @@ run_systools(NewVer, Name) ->
     end.
 
 boot_files(TargetDir, Ver, Name) ->
-    Tmp = "_tmp",
-    ok = file:make_dir(filename:join([".", Tmp])),
-    ok = file:make_dir(filename:join([".", Tmp, "releases"])),
-    ok = file:make_dir(filename:join([".", Tmp, "releases", Ver])),
+    ok = file:make_dir(filename:join([".", ?TMP])),
+    ok = file:make_dir(filename:join([".", ?TMP, "releases"])),
+    ok = file:make_dir(filename:join([".", ?TMP, "releases", Ver])),
     ok = file:make_symlink(
            filename:join(["start.boot"]),
-           filename:join([".", Tmp, "releases", Ver, Name ++ ".boot"])),
+           filename:join([".", ?TMP, "releases", Ver, Name ++ ".boot"])),
     {ok, _} = file:copy(
                 filename:join([TargetDir, "releases", Ver, "start_clean.boot"]),
-                filename:join([".", Tmp, "releases", Ver, "start_clean.boot"])).
+                filename:join([".", ?TMP, "releases", Ver, "start_clean.boot"])).
 
 make_tar(NameVer) ->
     Filename = NameVer ++ ".tar.gz",
     {ok, Cwd} = file:get_cwd(),
     Absname = filename:join([Cwd, Filename]),
-    ok = file:set_cwd("_tmp"),
+    ok = file:set_cwd(?TMP),
     ok = erl_tar:extract(Absname, [compressed]),
     ok = file:delete(Absname),
     {ok, Tar} = erl_tar:open(Absname, [write, compressed]),
@@ -176,7 +177,7 @@ cleanup(NameVer) ->
             ],
     lists:foreach(fun(F) -> ok = file:delete(F) end, Files),
 
-    ok = remove_dir_tree("_tmp").
+    ok = remove_dir_tree(?TMP).
 
 %% adapted from http://www.erlang.org/doc/system_principles/create_target.html
 remove_dir_tree(Dir) ->

test/upgrade_project/rel/files/dummy

@@ -50,6 +50,20 @@ ERTS_PATH=$RUNNER_BASE_DIR/erts-$ERTS_VSN/bin
 # Setup command to control the node
 NODETOOL="$ERTS_PATH/escript $ERTS_PATH/nodetool $NAME_ARG $COOKIE_ARG"
 
+# Use releases/VSN/sys.config if it exists otherwise use etc/app.config
+if [ -e "$RUNNER_BASE_DIR/releases/$APP_VSN/sys.config" ]; then
+    CONFIG_PATH="$RUNNER_BASE_DIR/releases/$APP_VSN/sys.config"
+else
+    CONFIG_PATH="$RUNNER_ETC_DIR/app.config"
+fi
+
+# Use releases/VSN/vm.args if it exists otherwise use etc/vm.args
+if [-e "$RUNNER_BASE_DIR/releases/$APP_VSN/vm.args" ]; then
+    VMARGS_PATH="$RUNNER_BASE_DIR/releases/$APP_VSN/vm.args"
+else
+    VMARGS_PATH="$RUNNER_ETC_DIR/vm.args"
+fi
+
 # Check the first argument for instructions
 case "$1" in
     start)
@@ -147,7 +161,7 @@ case "$1" in
         BINDIR=$ROOTDIR/erts-$ERTS_VSN/bin
         EMU=beam
         PROGNAME=`echo $0 | sed 's/.*\\///'`
-        CMD="$BINDIR/erlexec -boot $RUNNER_BASE_DIR/releases/$APP_VSN/$BOOTFILE -mode embedded -config $RUNNER_ETC_DIR/app.config -args_file $RUNNER_ETC_DIR/vm.args -- ${1+"$@"}"
+        CMD="$BINDIR/erlexec -boot $RUNNER_BASE_DIR/releases/$APP_VSN/$BOOTFILE -mode embedded -config $CONFIG_PATH -args_file $VMARGS_PATH -- ${1+"$@"}"
         export EMU
         export ROOTDIR
         export BINDIR

test/upgrade_project/rel/files/app.config → test/upgrade_project/rel/files/sys.config

@@ -8,4 +8,3 @@
          {error_logger_mf_maxfiles, 5}           % 5 files max
         ]}
 ].
-

test/upgrade_project/rel/reltool.config

@@ -20,6 +20,6 @@
           {copy, "files/erl", "{{erts_vsn}}/bin/erl"},
           {copy, "files/nodetool", "{{erts_vsn}}/bin/nodetool"},
           {copy, "files/dummy", "bin/dummy"},
-          {copy, "files/app.config", "etc/app.config"},
-          {copy, "files/vm.args", "etc/vm.args"}
+          {copy, "files/sys.config", "releases/\{\{rel_vsn\}\}/sys.config"},
+          {copy, "files/vm.args", "releases/\{\{rel_vsn\}\}/vm.args"}
           ]}.