release_handler rebar hot code swap

测试代码位置
appup文件的格式
操作步骤

测试代码位置

https://github.com/jixiuf/helloerlang/tree/master/release_handle

appup文件的格式

{Vsn, % Vsn 为当前version的appliction版本号
[{UpFromVsn1, InstructionsU1}, %UpFromVsn1 是前一版的版本号 ,InstructionsU1 是一个指令 list
…,
{UpFromVsnK, InstructionsUK}],
[{DownToVsn1, InstructionsD1},
…,
{DownToVsnK, InstructionsDK}]}.

参考：

操作步骤

cd release_handle/release_h/
make clean

cp src-0.1 src
make

先使用0.1版的src进行编译

make createnode
#这个make 指令其实执行如下命令
mkdir rel;cd rel;../rebar create-node nodeid=release_h

生成 ./rel目录,
不太明白为什么rebar起名字叫create-node
但是要想运行 rebar generate
./rel/目录下必须有rebar create-node nodeid=$(PROJECT) 命令生成的
一系列文件才行，比如 reltool.config
生成的reltool.config形如：

{sys, [
       {lib_dirs, []},
       {erts, [{mod_cond, derived}, {app_file, strip}]},
       {app_file, strip},
       {rel, "release_h", "1",
	[
	 kernel,
	 stdlib,
	 sasl,
	 release_h
	]},
       {rel, "start_clean", "",
	[
	 kernel,
	 stdlib
	]},
       {boot_rel, "release_h"},
       {profile, embedded},
       {incl_cond, exclude},
       {excl_archive_filters, [".*"]}, %% Do not archive built libs
       {excl_sys_filters, ["^bin/.*", "^erts.*/bin/(dialyzer|typer)",
			   "^erts.*/(doc|info|include|lib|man|src)"]},
       {excl_app_filters, ["\.gitignore"]},
       {app, sasl,   [{incl_cond, include}]},
       {app, stdlib, [{incl_cond, include}]},
       {app, kernel, [{incl_cond, include}]},
       {app, release_h, [{incl_cond, include}]}
      ]}.

{target_dir, "release_h"}.

{overlay, [
	   {mkdir, "log/sasl"},
	   {copy, "files/erl", "\{\{erts_vsn\}\}/bin/erl"},
	   {copy, "files/nodetool", "\{\{erts_vsn\}\}/bin/nodetool"},
	   {copy, "files/release_h", "bin/release_h"},
	   {copy, "files/release_h.cmd", "bin/release_h.cmd"},
	   {copy, "files/start_erl.cmd", "bin/start_erl.cmd"},
	   {copy, "files/install_upgrade.escript", "bin/install_upgrade.escript"},
	   {copy, "files/sys.config", "releases/\{\{rel_vsn\}\}/sys.config"},
	   {copy, "files/vm.args", "releases/\{\{rel_vsn\}\}/vm.args"}
	  ]}.

这个生成的reltool.config有几处需要修改

注释掉这一行，{app_file, strip},
可能是rebar bug的原因，
我在 rebar generate-upgrade。。。时，会报错，注释掉这句就可以了
{lib_dirs, ["../.."]},
将本项目源码所在目录加到reltool.config的 lib_dirs中，这里使用了相对
目径，这样 reltool才能找到本源目
修改版本号为0.1 {rel, "release_h", "0.1",…}

修改后的文件为

{sys, [
       {lib_dirs, ["../.."]},
       {erts, [{mod_cond, derived}, {app_file, strip}]},
       %% {app_file, strip},
       {rel, "release_h", "0.1",
	[
	 kernel,
	 stdlib,
	 sasl,
	 release_h
	]},
       {rel, "start_clean", "",
	[
	 kernel,
	 stdlib
	]},
       {boot_rel, "release_h"},
       {profile, embedded},
       {incl_cond, exclude},
       {excl_archive_filters, [".*"]}, %% Do not archive built libs
       {excl_sys_filters, ["^bin/.*", "^erts.*/bin/(dialyzer|typer)",
			   "^erts.*/(doc|info|include|lib|man|src)"]},
       {excl_app_filters, ["\.gitignore"]},
       {app, sasl,   [{incl_cond, include}]},
       {app, stdlib, [{incl_cond, include}]},
       {app, kernel, [{incl_cond, include}]},
       {app, release_h, [{incl_cond, include}]}
      ]}.

{target_dir, "release_h"}.

{overlay, [
	   {mkdir, "log/sasl"},
	   {copy, "files/erl", "\{\{erts_vsn\}\}/bin/erl"},
	   {copy, "files/nodetool", "\{\{erts_vsn\}\}/bin/nodetool"},
	   {copy, "files/release_h", "bin/release_h"},
	   {copy, "files/release_h.cmd", "bin/release_h.cmd"},
	   {copy, "files/start_erl.cmd", "bin/start_erl.cmd"},
	   {copy, "files/install_upgrade.escript", "bin/install_upgrade.escript"},
	   {copy, "files/sys.config", "releases/\{\{rel_vsn\}\}/sys.config"},
	   {copy, "files/vm.args", "releases/\{\{rel_vsn\}\}/vm.args"}
	  ]}.

生成 ./rel/release_h

make generate
#实际运行的是 ./rebar generate

可以查看下确保release_h-0.1被 打包到相应版本中
 ls ./rel/release_h/lib/|grep release_h
mv ./rel/release_h/ ./rel/release_h-0.1/

0.1版的release_h已经生成好了,适运行一下

cd ./rel/release_h/bin
./release_h console

Eshell V5.9.1  (abort with ^G)
(release_h@jixiufeng-Joseph)1> hello_gen:hello().
1
(release_h@jixiufeng-Joseph)2> hello_gen:module_info(attributes).
[{vsn,"0.1"}]
(release_h@jixiufeng-Joseph)3>
(release_h@jixiufeng-Joseph)3> release_handler:which_releases().
[{"release_h","0.1",
  ["kernel-2.15.1","stdlib-1.18.1","sasl-2.2.1",
   "release_h-0.1"],
  permanent}]
(release_h@jixiufeng-Joseph)4> tool:sayhello().
this is just a common module withou process running on ,so
update this module is easy
ok
(release_h@jixiufeng-Joseph)5>

修改./rel/reltool.config
将版本号由0.1改成0.2

rm src
cp src-0.2 src
make clean
make
make generate
ls rel/release_h/lib/|grep release_h
make up
ls rel/release_h/lib/release_h*/ebin |grep appup
ls rel/|grep tar
cp rel/release_h_0.2.tar.gz ./rel/release_h-0.1/releases/

用0.2版的代码生成新的 ./rel/release_h/
注意在0.2版的代码中 src/有 release_h.appup.src
编译过程中，会放到 ebin/release_h.appup
make up 命令执行两个命令

./rebar generate-appups previous_release=release_h-0.1
./rebar generate-upgrade previous_release=release_h-0.1

关于参数previous_release后面跟相对于./rel/目录的路径，比如，我将0.1版的
release_h目录命名为 release_h-0.1
generate-appups会在 ./rel/release_h/lib/release_h-0.2/ebin目录下生成
release_h.appup文件
如果你的ebin/目录下没有appup文件的话， rebar 会为你生成一个，然后这它放到
./rel/release_h/lib/release_h-0.2/ebin目录中
generate-upgrade命令会在./rebar 生成一个tar.gz包

把release_h_0.2.tar.gz升级包  copy到 0.1版 的releases目录下
cp ./rel/release_h_0.2.tar.gz ./rel/release-0.1/releases/

在刚才测试0.1版的erlang shell中执行

erl> release_handler:unpack_release("release_h_0.2"). %解包
erl> release_handler:install_release("0.2"). % install
erl> release_handler:make_permanent("0.2"). % 使0.2版成为默认版本

(release_h@jixiufeng-Joseph)2> release_handler:unpack_release("release_h_0.2").
{ok,"0.2"}
(release_h@jixiufeng-Joseph)3>  release_handler:install_release("0.2").
if you see this line ,that means hello_gen.erl is updated
hello_gen update from version 0.1 and current version is 0.2
and the third param Extra is "Extra info for code_change/3"

if you see this line that means world_gen is started
{ok,"0.1",[]}
(release_h@jixiufeng-Joseph)4>  release_handler:make_permanent("0.2").
ok
(release_h@jixiufeng-Joseph)5>

查看一下确认已经升级到0.2

(release_h@jixiufeng-Joseph)5> release_handler:which_releases().
[{"release_h","0.2",
  ["kernel-2.15.1","stdlib-1.18.1","sasl-2.2.1",
   "release_h-0.2"],
  current},
 {"release_h","0.1",
  ["kernel-2.15.1","stdlib-1.18.1","sasl-2.2.1",
   "release_h-0.1"],
  permanent}]
(release_h@jixiufeng-Joseph)7> whereis(world_gen).
<0.60.0>
(release_h@jixiufeng-Joseph)10> supervisor:which_children(hello_sup).
[{world_gen,<0.60.0>,worker,[world_gen]},
 {hello_gen,<0.49.0>,worker,[hello_gen]}]
(release_h@jixiufeng-Joseph)11>
(release_h@jixiufeng-Joseph)11> tool:sayworld().
this is just a common module withou process running on ,so
update this module is easy

拾遗笔记

release_handler rebar hot code swap

Table of Contents

测试代码位置

appup文件的格式

操作步骤

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