Examples

Start livebook from beamtools

As livebook is included into standard beamtools SDK, it's possible to start a livebook session easily following the steps below:

1. Source the beamtools SDK

   source /home/your_username/beamtools/environment-setup-x86_64-pokysdk-linux

2. Check if the livebook scripts exists in your environment:

   $ livebook
   Usage: livebook COMMAND [ARGS]
   
   The known commands are:
   
   start          Starts the system
   start_iex      Starts the system with IEx attached
   daemon         Starts the system as a daemon
   daemon_iex     Starts the system as a daemon with IEx attached
   eval "EXPR"    Executes the given expression on a new, non-booted system
   rpc "EXPR"     Executes the given expression remotely on the running system
   remote         Connects to the running system via a remote shell
   restart        Restarts the running system via a remote command
   stop           Stops the running system via a remote command
   pid            Prints the operating system PID of the running system via a remote command
   version        Prints the release name and version to be booted
   

3. Start livebook system:

   $ livebook start
   [Livebook] Application running at http://localhost:8080/?token=z4nrl62iqojkttdq3fuha7vm7ynkhwis

4. It's done, you can play with livebook locally without need to install anything else.

Building and starting erlang-red application

Let's try erlang-red application building it from source code.

1. Source the beamtools SDK

   source /home/your_username/beamtools/environment-setup-x86_64-pokysdk-linux

2. Fetch erlang-red source code:

   git clone https://github.com/gorenje/erlang-red

3. Next, it is time to build erlang-red which is a rebar3 project:

   cd erlang-red
   export ERL_CFLAGS="-I${ERL_EI_INCLUDE_DIR} -I${ERL_ERTS_INCLUDE_DIR}"
   rebar3 compile

   The ERL_CFLAGS exported variable is needed in order to indicate the right place where Erlang headers can be find. For erlang-red context, the library circuits_i2c needs that includes. And beamtools already exports two variables (ERL_EI_INCLUDE_DIR and ERL_ERTS_INCLUDE_DIR) to help with this ERL_CFLAGS variable.

4. Run erlang-red using rebar3 shell:

   rebar3 shell --apps erlang_red
   ===> Verifying dependencies...
   ===> Analyzing applications...
   ===> Compiling erlang_red
   Erlang/OTP 28 [erts-16.0.3] [source] [64-bit] [smp:12:12] [ds:12:12:10] [async-threads:1] [jit:ns]
   
   Eshell V16.0.3 (press Ctrl+G to abort, type help(). for help)
   ===> Booted cowlib
   
   ===> Booted ranch
   
   ===> Booted cowboy
   
   ===> Booted circuits_i2c
   
   ===> Booted erlang_red_parsers
   
   ===> Booted erlang_red
   
   1>

   And check the results at http://localhost:8080/erlang-red

   If you want to change the default 8080 tcp port, use the environment variable PORT to change it.

5. As a last step, let's also make an erlang-red release:

   rebar3 release
   ===> Verifying dependencies...
   ===> Analyzing applications...
   ===> Compiling erlang_red
   ===> Assembling release erlang_red-0.3.4...
   ===> There are missing function calls in the release.
   ===> Make sure all applications needed at runtime are included in the release.
   ===> ered_http_release_status:handle_get_response/2 calls undefined function status_tmpl:render/1
   ===> Release successfully assembled: _build/default/rel/erlang_red

   The folder _build/default/rel/erlang_red has an erlang-red release with everything needed in order to run erlang-red.

Building observer_cli

observer_cli is an application for visualizing Erlang/Elixir nodes on the command line.

1. Source the beamtools SDK

   source /home/your_username/beamtools/environment-setup-x86_64-pokysdk-linux

2. Fetch observer_cli source code:

   git clone https://github.com/zhongwencool/observer_cli

3. Build it:

   rebar3 escriptize

   Produces a escript file at _build/default/bin/observer_cli

4. Try to run observer_cli:

   _build/default/bin/observer_cli
   Usage: observer_cli TARGETNODE [TARGETCOOKIE REFRESHMS]