basic erlang node skeleton

Author: Cloven

apps/skel/ebin/skel.app

@@ -0,0 +1,8 @@
+{application,skel,
+             [{description,[]},
+              {vsn,"1"},
+              {registered,[]},
+              {applications,[kernel,stdlib]},
+              {mod,{skel_app,[]}},
+              {env,[]},
+              {modules,[skel_app,skel_sup]}]}.

apps/skel/src/skel.app.src

@@ -0,0 +1,12 @@
+{application, skel,
+ [
+  {description, ""},
+  {vsn, "1"},
+  {registered, []},
+  {applications, [
+                  kernel,
+                  stdlib
+                 ]},
+  {mod, { skel_app, []}},
+  {env, []}
+ ]}.

apps/skel/src/skel_app.erl

@@ -0,0 +1,16 @@
+-module(skel_app).
+
+-behaviour(application).
+
+%% Application callbacks
+-export([start/2, stop/1]).
+
+%% ===================================================================
+%% Application callbacks
+%% ===================================================================
+
+start(_StartType, _StartArgs) ->
+    skel_sup:start_link().
+
+stop(_State) ->
+    ok.

apps/skel/src/skel_sup.erl

@@ -0,0 +1,28 @@
+
+-module(skel_sup).
+
+-behaviour(supervisor).
+
+%% API
+-export([start_link/0]).
+
+%% Supervisor callbacks
+-export([init/1]).
+
+%% Helper macro for declaring children of supervisor
+-define(CHILD(I, Type), {I, {I, start_link, []}, permanent, 5000, Type, [I]}).
+
+%% ===================================================================
+%% API functions
+%% ===================================================================
+
+start_link() ->
+    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
+%% ===================================================================
+%% Supervisor callbacks
+%% ===================================================================
+
+init([]) ->
+    {ok, { {one_for_one, 5, 10}, []} }.
+

apps/skelnode/ebin/skelnode.app

@@ -0,0 +1,8 @@
+{application,skelnode,
+             [{description,[]},
+              {vsn,"1"},
+              {registered,[]},
+              {applications,[kernel,stdlib]},
+              {mod,{skelnode_app,[]}},
+              {env,[]},
+              {modules,[skelnode_app,skelnode_sup]}]}.

apps/skelnode/src/skelnode.app.src

@@ -0,0 +1,12 @@
+{application, skelnode,
+ [
+  {description, ""},
+  {vsn, "1"},
+  {registered, []},
+  {applications, [
+                  kernel,
+                  stdlib
+                 ]},
+  {mod, { skelnode_app, []}},
+  {env, []}
+ ]}.

apps/skelnode/src/skelnode_app.erl

@@ -0,0 +1,16 @@
+-module(skelnode_app).
+
+-behaviour(application).
+
+%% Application callbacks
+-export([start/2, stop/1]).
+
+%% ===================================================================
+%% Application callbacks
+%% ===================================================================
+
+start(_StartType, _StartArgs) ->
+    skelnode_sup:start_link().
+
+stop(_State) ->
+    ok.

apps/skelnode/src/skelnode_sup.erl

@@ -0,0 +1,28 @@
+
+-module(skelnode_sup).
+
+-behaviour(supervisor).
+
+%% API
+-export([start_link/0]).
+
+%% Supervisor callbacks
+-export([init/1]).
+
+%% Helper macro for declaring children of supervisor
+-define(CHILD(I, Type), {I, {I, start_link, []}, permanent, 5000, Type, [I]}).
+
+%% ===================================================================
+%% API functions
+%% ===================================================================
+
+start_link() ->
+    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
+%% ===================================================================
+%% Supervisor callbacks
+%% ===================================================================
+
+init([]) ->
+    {ok, { {one_for_one, 5, 10}, []} }.
+

rebar

@@ -0,0 +1 @@
+{sub_dirs, ["apps/skel", "apps/skelnode", "rel"]}.

rebar.config

@@ -0,0 +1,44 @@
+#!/bin/sh
+
+# /bin/sh on Solaris is not a POSIX compatible shell, but /usr/bin/ksh is.
+if [ `uname -s` = 'SunOS' -a "${POSIX_SHELL}" != "true" ]; then
+    POSIX_SHELL="true"
+    export POSIX_SHELL
+    exec /usr/bin/ksh $0 "$@"
+fi
+
+# clear it so if we invoke other scripts, they run as ksh as well
+unset POSIX_SHELL
+
+## This script replaces the default "erl" in erts-VSN/bin. This is
+## necessary as escript depends on erl and in turn, erl depends on
+## having access to a bootscript (start.boot). Note that this script
+## is ONLY invoked as a side-effect of running escript -- the embedded
+## node bypasses erl and uses erlexec directly (as it should).
+##
+## Note that this script makes the assumption that there is a
+## start_clean.boot file available in $ROOTDIR/release/VSN.
+
+# Determine the abspath of where this script is executing from.
+ERTS_BIN_DIR=$(cd ${0%/*} && pwd)
+
+# Now determine the root directory -- this script runs from erts-VSN/bin,
+# so we simply need to strip off two dirs from the end of the ERTS_BIN_DIR
+# path.
+ROOTDIR=${ERTS_BIN_DIR%/*/*}
+
+# Parse out release and erts info
+START_ERL=`cat $ROOTDIR/releases/start_erl.data`
+ERTS_VSN=${START_ERL% *}
+APP_VSN=${START_ERL#* }
+
+BINDIR=$ROOTDIR/erts-$ERTS_VSN/bin
+EMU=beam
+PROGNAME=`echo $0 | sed 's/.*\\///'`
+CMD="$BINDIR/erlexec"
+export EMU
+export ROOTDIR
+export BINDIR
+export PROGNAME
+
+exec $CMD -boot $ROOTDIR/releases/$APP_VSN/start_clean ${1+"$@"}

rel/files/erl

@@ -0,0 +1,44 @@
+#!/usr/bin/env escript
+%%! -noshell -noinput
+%% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
+%% ex: ft=erlang ts=4 sw=4 et
+
+-define(TIMEOUT, 60000).
+-define(INFO(Fmt,Args), io:format(Fmt,Args)).
+
+main([NodeName, Cookie, ReleasePackage]) ->
+    TargetNode = start_distribution(NodeName, Cookie),
+    {ok, Vsn} = rpc:call(TargetNode, release_handler, unpack_release,
+                         [ReleasePackage], ?TIMEOUT),
+    ?INFO("Unpacked Release ~p~n", [Vsn]),
+    {ok, OtherVsn, Desc} = rpc:call(TargetNode, release_handler,
+                                    check_install_release, [Vsn], ?TIMEOUT),
+    {ok, OtherVsn, Desc} = rpc:call(TargetNode, release_handler,
+                                    install_release, [Vsn], ?TIMEOUT),
+    ?INFO("Installed Release ~p~n", [Vsn]),
+    ok = rpc:call(TargetNode, release_handler, make_permanent, [Vsn], ?TIMEOUT),
+    ?INFO("Made Release ~p Permanent~n", [Vsn]);
+main(_) ->
+    init:stop(1).
+
+start_distribution(NodeName, Cookie) ->
+    MyNode = make_script_node(NodeName),
+    {ok, _Pid} = net_kernel:start([MyNode, shortnames]),
+    erlang:set_cookie(node(), list_to_atom(Cookie)),
+    TargetNode = make_target_node(NodeName),
+    case {net_kernel:hidden_connect_node(TargetNode),
+          net_adm:ping(TargetNode)} of
+        {true, pong} ->
+            ok;
+        {_, pang} ->
+            io:format("Node ~p not responding to pings.\n", [TargetNode]),
+            init:stop(1)
+    end,
+    TargetNode.
+
+make_target_node(Node) ->
+    [_, Host] = string:tokens(atom_to_list(node()), "@"),
+    list_to_atom(lists:concat([Node, "@", Host])).
+
+make_script_node(Node) ->
+    list_to_atom(lists:concat([Node, "_upgrader_", os:getpid()])).