warp/examples/erlang

You need to have Erlang/OTP, Rebar3 (Erlang build tool) and warp-packer installed to create self-contained binary Erlang release.

Linux

Create new application using rebar3:

~ $ rebar3 new app foo && cd foo

===> Writing foo/src/foo_app.erl
===> Writing foo/src/foo_sup.erl
===> Writing foo/src/foo.app.src
===> Writing foo/rebar.config
===> Writing foo/.gitignore
===> Writing foo/LICENSE
===> Writing foo/README.md

~/foo $ 

Make a directory (e.g. config) to place warp launcher in it:

~/foo $ mkdir config

Create ./config/launch file with below contents:

#!/bin/sh

DIR="$(cd "$(dirname "$0")" ; pwd -P)"
APP=$DIR/bin/{{release_name}}

exec $APP $@

We used mustache template to let rebar3 place your release name in script dynamically. Here it is foo.

Make launcher file executable:

~/foo $ chmod a+x config/launch

Edit rebar.config file and add relx section:

% ...

{relx, [{release, { foo, "0.1.0" }, [foo, sasl]},

        {dev_mode, false},
        {include_erts, true}, % To include Erlang runtime system
        {extended_start_script, true}, % Should be true

        {overlay, [{template, "./config/launch", "launch"}]}] % copies our launcher file to release directory
}.

% ...

Make a release:

~/foo $ rebar3 release

===> Verifying dependencies...
===> Compiling foo
===> Starting relx build process ...
===> Resolving OTP Applications from directories:
          /opt/foo/_build/default/lib
          /usr/local/lib/erlang/lib
          /opt/foo/_build/default/rel
===> Resolved foo-0.1.0
===> Including Erts from /usr/local/lib/erlang
===> release successfully created!

Now launcher file should be in your release directory:

~/foo $ ls _build/default/rel/foo 
bin  erts-10.1  launch  lib  releases

Before running warp-packer, It's better to test release itself:

~/foo $ ./_build/default/rel/foo/bin/foo start
~/foo $ ./_build/default/rel/foo/bin/foo ping
pong
~/foo $ ./_build/default/rel/foo/bin/foo stop
ok

Build self-contained binary file from release:

~/foo $ warp-packer -a linux-x64 -i _build/default/rel/foo -e launch -o foo

Compressing input directory "_build/default/rel/foo"...
Creating self-contained application binary "foo"...
All done

Test it:

~/foo $ ./foo start

~/foo $ ./foo ping
pong

~/foo $ ./foo remote_console
Erlang/OTP 21 [erts-10.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe]

Eshell V10.1  (abort with ^G)
(foo@localhost)1>
BREAK: (a)bort (c)ontinue (p)roc info (i)nfo (l)oaded
       (v)ersion (k)ill (D)b-tables (d)istribution

~/foo $ ./foo stop
ok

~/foo $ ./foo ping
Node foo@localhost not responding to pings.

Advanced

You can place warp command in rebar.config. Then rebar3 will run it when you are making release:

% ...

{post_hooks, [{release, "warp-packer -a linux-x64 -i _build/default/rel/foo -e launch -o foo"}]}.

% ...

Now make release:

~/foo $ rebar3 release

===> Verifying dependencies...
===> Compiling foo
===> Starting relx build process ...
===> Resolving OTP Applications from directories:
          /opt/foo/_build/default/lib
          /usr/local/lib/erlang/lib
          /opt/foo/_build/default/rel
===> Resolved foo-0.1.0
===> Including Erts from /usr/local/lib/erlang
===> release successfully created!
Compressing input directory "_build/default/rel/foo"...
Creating self-contained application binary "foo"...
All done

Note that rebar3 uses a templating approach to make an application structure. If you built rebar3by yourself, and did not use its escript, Its own templates are placed in /path/to/installed/rebar3/priv/templates. You can place your launch file there and add below lines at the end of app.template:

% ...
{file, "launch", "{{name}}/config/launch"}. % copies launch file to YourApp/config/launch
{chmod, "{{name}}/config/launch", 8#755}. % makes file executable

Also edit app_rebar.config and place our relx and post_hooks at the end of file:

% ...

{relx, [{release, { {{name}}, "0.1.0" },
         [{{name}}, sasl]},

        {dev_mode, false},
        {include_erts, true},

        {extended_start_script, true},
        {overlay, [{template, "./config/launch", "launch"}]}]
}.

{post_hooks, [{release, "warp-packer -a linux-x64 -i _build/default/rel/{{name}} -e launch -o {{name}}"}]}.

In above {{name}} is what you will pass to rebar3 new app as application name. Recompile rebar3 itself again:

/path/to/rebar3 $ ./bootsrtap
...

Create new application again:

~ $ rebar3 new app bar && cd bar

===> Writing bar/src/bar_app.erl
===> Writing bar/src/bar_sup.erl
===> Writing bar/src/bar.app.src
===> Writing bar/rebar.config
===> Writing bar/.gitignore
===> Writing bar/LICENSE
===> Writing bar/README.md
===> Writing bar/config/launch

Make a release:

~/bar $ rebar3 release

===> Verifying dependencies...
===> Compiling bar
===> Starting relx build process ...
===> Resolving OTP Applications from directories:
          /opt/bar/_build/default/lib
          /usr/local/lib/erlang/lib
===> Resolved bar-0.1.0
===> Including Erts from /usr/local/lib/erlang
===> release successfully created!
Compressing input directory "_build/default/rel/bar"...
Creating self-contained application binary "bar"...
All done

Test it:

~/bar $ ./bar start

~/bar $ ./bar ping
pong

~/bar $ ./bar stop
ok

Also you can add it for rebar3 new release | lib or build your own template and add it to your template.