I'm trying to figure out how to use rebar to:
- create erlang project
- add a dependency on an erlang module from github
- start the app via the erl console
- create a release and start the app from the release (via the generated scripts)
- What's the best way to declare dependencies for erlang? I would have thought using rebar's transitive dependency management would be the way to go... put external dependencies in rebar.config, run 'rebar get-deps && rebar compile' and you're off to the races. But this thread indicates that this could break apps with shared dependencies. If both apps A and B depend on C, and C hoarks, then both apps A and B die, too.
[stack overflow question] http://stackoverflow.com/questions/11141198/when-to-use-erlang-applicationstart-or-included-applications-and-a-supervisor)
I realize this is an extension to the above question, but I'm hoping that we can get some more discussion going by re-posting the question.
- Assuming that this thread was incorrect, and that rebar dependencies are the way to go, I'm having a teensy problem. I was following Dizzy's 2011 presentation (http://vimeo.com/22700527) and thought, sweet, I'll create a sample app and have it depend on ibrowse (very cool app).
$ mkdir foo
$ cd foo
$ rebar create-app appid=foo
$ find .
.
./src
./src/foo_sup.erl
./src/foo.app.src
./src/foo_app.erl
$ rebar compile
==> foo (compile)
Compiled src/foo_app.erl
Compiled src/foo_sup.erl
rebar.config (add this at project root)
{deps, [
{ibrowse, ".*", {git, "git://github.com/cmullaparthi/ibrowse.git", {tag, "v4.0.1"}}}
]
}.
$ rebar get-deps
==> foo (get-deps)
Pulling ibrowse from {git,"git://github.com/cmullaparthi/ibrowse.git",
{tag,"v4.0.1"}}
Cloning into 'ibrowse'...
==> ibrowse (get-deps)
$ rebar compile
==> ibrowse (compile)
Compiled src/ibrowse_lib.erl
Compiled src/ibrowse_lb.erl
Compiled src/ibrowse_app.erl
Compiled src/ibrowse_test.erl
Compiled src/ibrowse_sup.erl
Compiled src/ibrowse.erl
/home/todd/projects/erlang/foo/deps/ibrowse/src/ibrowse_http_client.erl:999: Warning: variable 'State' is unused
Compiled src/ibrowse_http_client.erl
==> foo (compile)
Add 'ibrowse' to my foo application's list of dependencies...(per instructions here http://www.erlang.org/doc/man/app.html).
deps/ibrowse/ebin/ibrowse.app shows:
Application = ibrowse
Ok, so I'll update my src/foo.app.src from:
{application, foo,
[
{description, ""},
{vsn, "1"},
{registered, []},
{applications, [
kernel,
stdlib
]},
{mod, { foo_app, []}},
{env, []}
]}.
to
{application, foo,
[
{description, ""},
{vsn, "1"},
{registered, []},
{applications, [
kernel,
stdlib,
<<< added >>> ibrowse
]},
{mod, { foo_app, []}},
{env, []}
]}.
$ rebar compile
Check that the ebin/foo.app has been updated to include the ibrowse dependency...
{application,foo,
[{description,[]},
{vsn,"1"},
{registered,[]},
{applications,[kernel,stdlib,ibrowse]},
{mod,{foo_app,[]}},
{env,[]},
{modules,[foo_app,foo_sup]}]}.
Ok, looks good.
$ erl -pa ebin/ -pa deps/ibrowse/ebin/
Erlang R15B02 (erts-5.9.2) [source] [64-bit] [smp:6:6] [async-threads:0] [hipe] [kernel-poll:false]
Eshell V5.9.2 (abort with ^G)
1> application:start(foo).
{error,{not_started,ibrowse}}
Ok, that didn't work...
$ erl -pa ebin/ -pa deps/ibrowse/ebin/
Erlang R15B02 (erts-5.9.2) [source] [64-bit] [smp:6:6] [async-threads:0] [hipe] [kernel-poll:false]
Eshell V5.9.2 (abort with ^G)
1> ibrowse:start().
{ok,<0.34.0>}
2> application:start(foo).
{error,{not_started,ibrowse}}
Ok, I contacted some friends and erlang experts to figure out what I was doing wrong. The word from on-high goes like this:
- get the dependency (ibrowse, in this case), into the project using rebar.config as in #3 above
- from within the erlang shell, start the dependency (ibrowse) before this app (below)
Let's try it...
$ erl -pa ebin/ -pa deps/ibrowse/ebin/
Erlang R15B02 (erts-5.9.2) [source] [64-bit] [smp:6:6] [async-threads:0] [hipe] [kernel-poll:false]
Eshell V5.9.2 (abort with ^G)
1> application:start(ibrowse).
ok
2> application:start(foo).
ok
3> regs().
** Registered procs on node nonode@nohost **
Name Pid Initial Call Reds Msgs
application_controlle <0.6.0> erlang:apply/2 6091 0
code_server <0.19.0> erlang:apply/2 113604 0
erl_prim_loader <0.3.0> erlang:apply/2 182938 0
error_logger <0.5.0> gen_event:init_it/6 265 0
file_server_2 <0.18.0> file_server:init/1 113 0
foo_sup <0.44.0> supervisor:foo_sup/1 41 0
global_group <0.17.0> global_group:init/1 59 0
global_name_server <0.12.0> global:init/1 50 0
ibrowse <0.38.0> ibrowse:init/1 962 0
ibrowse_sup <0.37.0> supervisor:ibrowse_sup/1 104 0
inet_db <0.15.0> inet_db:init/1 220 0
init <0.0.0> otp_ring0:start/2 4278 0
kernel_safe_sup <0.28.0> supervisor:kernel/1 58 0
kernel_sup <0.10.0> supervisor:kernel/1 34950 0
rex <0.11.0> rpc:init/1 35 0
standard_error <0.21.0> erlang:apply/2 9 0
standard_error_sup <0.20.0> supervisor_bridge:standar 41 0
user <0.24.0> group:server/3 36 0
user_drv <0.23.0> user_drv:server/2 1017 0
** Registered ports on node nonode@nohost **
Name Id Command
ok
4>
Advice from friends suggests: for releases, use reltool and it will "calculate the load/start order for you and encode it into the boot script
Following instructions from:
$ mkdir rel
$ cd rel
$ rebar create-node nodeid=foo
├── deps
│ └── ibrowse
├── ebin
│ ├── foo.app
│ ├── foo_app.beam
│ └── foo_sup.beam
├── rebar.config
├── rel
│ ├── files
│ ├── foo
│ └── reltool.config
└── src
├── foo_app.erl
├── foo.app.src
└── foo_sup.erl
$ cat foo/rel/reltool.config
{sys, [
{lib_dirs, []},
{erts, [{mod_cond, derived}, {app_file, strip}]},
{app_file, strip},
{rel, "foo", "1",
[
kernel,
stdlib,
sasl,
ibrowse,
foo
]},
{rel, "start_clean", "",
[
kernel,
stdlib
]},
{boot_rel, "foo"},
{profile, embedded},
{incl_cond, derived},
{mod_cond, derived},
{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, ibrowse, [{mod_cond, app}, {incl_cond, include}, {lib_dir, "../deps/ibrowse"}]},
{app, foo, [{mod_cond, app}, {incl_cond, include}, {lib_dir, ".."}]}
]}.
{target_dir, "foo"}.
{overlay, [
{mkdir, "log/sasl"},
{copy, "files/erl", "\{\{erts_vsn\}\}/bin/erl"},
{copy, "files/nodetool", "\{\{erts_vsn\}\}/bin/nodetool"},
{copy, "files/foo", "bin/foo"},
{copy, "files/foo.cmd", "bin/foo.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"}
]}.
$ cd foo
$ rebar compile generate
[foo]$ rebar compile generate
==> ibrowse (compile)
Compiled src/ibrowse_lb.erl
Compiled src/ibrowse_app.erl
Compiled src/ibrowse_lib.erl
Compiled src/ibrowse_test.erl
Compiled src/ibrowse_sup.erl
Compiled src/ibrowse.erl
/home/todd/projects/erlang/foo_project/foo/deps/ibrowse/src/ibrowse_http_client.erl:999: Warning: variable 'State' is unused
Compiled src/ibrowse_http_client.erl
==> rel (compile)
==> foo (compile)
Compiled src/foo_app.erl
Compiled src/foo_sup.erl
==> rel (generate)
[foo]$ sh rel/foo/bin/foo console
Exec: /home/todd/projects/erlang/foo_project/foo/rel/foo/erts-5.9.2/bin/erlexec -boot /home/todd/projects/erlang/foo_project/foo/rel/foo/releases/1/foo -mode embedded -config /home/todd/projects/erlang/foo_project/foo/rel/foo/releases/1/sys.config -args_file /home/todd/projects/erlang/foo_project/foo/rel/foo/releases/1/vm.args -- console
Root: /home/todd/projects/erlang/foo_project/foo/rel/foo
Erlang R15B02 (erts-5.9.2) [source] [64-bit] [smp:6:6] [async-threads:0] [hipe] [kernel-poll:false]
Eshell V5.9.2 (abort with ^G)
(foo@127.0.0.1)1>
(foo@127.0.0.1)1> application:which_applications().
[{foo,[],"1"},
{ibrowse,"Erlang HTTP client application","4.0.1"},
{sasl,"SASL CXC 138 11","2.2.1"},
{stdlib,"ERTS CXC 138 10","1.18.2"},
{kernel,"ERTS CXC 138 10","2.15.2"}]
(foo@127.0.0.1)2> regs().
** Registered procs on node 'foo@127.0.0.1' **
Name Pid Initial Call Reds Msgs
alarm_handler <0.44.0> gen_event:init_it/6 28 0
application_controlle <0.6.0> erlang:apply/2 3608 0
auth <0.19.0> auth:init/1 43 0
code_server <0.25.0> erlang:apply/2 34428 0
erl_epmd <0.18.0> erl_epmd:init/1 131 0
erl_prim_loader <0.3.0> erlang:apply/2 164809 0
error_logger <0.5.0> gen_event:init_it/6 2513 0
file_server_2 <0.24.0> file_server:init/1 274 0
foo_sup <0.57.0> supervisor:foo_sup/1 41 0
global_group <0.23.0> global_group:init/1 59 0
global_name_server <0.12.0> global:init/1 50 0
ibrowse <0.52.0> ibrowse:init/1 1121 0
ibrowse_sup <0.51.0> supervisor:ibrowse_sup/1 97 0
inet_db <0.15.0> inet_db:init/1 261 0
init <0.0.0> otp_ring0:start/2 25837 0
kernel_safe_sup <0.34.0> supervisor:kernel/1 58 0
kernel_sup <0.10.0> supervisor:kernel/1 385824 0
net_kernel <0.20.0> net_kernel:init/1 428 0
net_sup <0.17.0> supervisor:erl_distributi 265 0
overload <0.45.0> overload:init/1 39 0
release_handler <0.46.0> release_handler:init/1 4137 0
rex <0.11.0> rpc:init/1 28 0
sasl_safe_sup <0.43.0> supervisor:sasl/1 156 0
sasl_sup <0.42.0> supervisor:sasl/1 151 0
standard_error <0.27.0> erlang:apply/2 9 0
standard_error_sup <0.26.0> supervisor_bridge:standar 41 0
user <0.30.0> group:server/3 20 0
user_drv <0.29.0> user_drv:server/2 814 0
** Registered ports on node 'foo@127.0.0.1' **
Name Id Command
ok
I had some great advice from the erlang mailing list, and this advice caused me to go and re-read some documentation:
This has the stock info you'd expect: http://www.erlang.org/doc/apps/reltool/index.html
But the pdf is actually more useful, as it has some examples showing multiple {app...} stanzas: http://www.erlang.org/doc/apps/reltool/reltool.pdf
For example, from the pdf, on page 10:
{sys, [{escript,
"examples/display_args",
[{incl_cond, include}]},
{app, inets, [{incl_cond, include}]},
{app, mnesia, [{incl_cond, exclude}]},
{app, ssl, [{incl_cond, exclude}]},
{app, runtime_tools, [{incl_cond, exclude}]},
{app, syntax_tools, [{incl_cond, exclude}]}]}.
{sys,[{escript,"examples/display_args",[{incl_cond,include}]},
{app,inets,[{incl_cond,include}]},
{app,mnesia,[{incl_cond,exclude}]},
{app,ssl,[{incl_cond,exclude}]},
{app,runtime_tools,[{incl_cond,exclude}]},
{app,syntax_tools,[{incl_cond,exclude}]}]}
The key thing I was getting hung up on was how to include apps in the release configuration file, reltool.config:
First, make sure foo and it's dependency, ibrowse, are listed as part of the release:
{rel, "foo", "1",
[
kernel,
stdlib,
sasl,
ibrowse,
foo
]},
Second, add the apps to the last part of {sys...
{app, ibrowse, [{mod_cond, app}, {incl_cond, include}, {lib_dir, "../deps/ibrowse"}]},
{app, foo, [{mod_cond, app}, {incl_cond, include}, {lib_dir, ".."}]}
Clearly I don't fully understand all this....I'll also be re-reading this page a few more times:
I am trying to compile code with below command(In windows 10 ).
command:
rebar3 compile
Result:
===> Verifying dependencies...
===> Fetching erlsom ({git,"https://github.com/willemdj/erlsom",
{ref,"472d07090b0b34aa2f7ba3fcaa168371e95172ed"}})
===> Failed to fetch and copy dep: {git,"https://github.com/willemdj/erlsom",
{ref,
"472d07090b0b34aa2f7ba3fcaa168371e95172ed"}}
When I try to clone git repo manullay I am getting below error:
Command:
git clone https://github.com/willemdj/erlsom
Result:
Cloning into 'erlsom'...
fatal: unable to access 'https://github.com/willemdj/erlsom/': Received HTTP code 404 from proxy after CONNECT
Please help why I am getting "Failed to fetch and copy dep:" error