nodex v0.1.2 Nodex.Distributed

A module to help setting up a distributed environment.

Examples

Starting and stopping a distributed environment:

iex> Node.alive?
false
iex> Nodex.Distributed.up
iex> Node.alive?
true
iex> Nodex.Distributed.down
iex> Node.alive?
false

Spawning 2 new slaves:

iex> Nodex.Distributed.up
iex> Nodex.Distributed.spawn_slaves(2)
[:"slave1@127.0.0.1", :"slave2@127.0.0.1"]

Loading a dynamically defined module onto a remote node and call a function on it remotely:

iex> Nodex.Distributed.up
iex> [node] = Nodex.Distributed.spawn_slaves(1)
iex> {:module, module, object_code, _} = defmodule A, do: def greet, do: "hi from " <> to_string(Node.self)
iex> Nodex.Distributed.rpc(node, A, :greet, []) # this won't work, A is not present on the remote node
iex> Nodex.Distributed.load_object_code(node, module, object_code)
iex> Nodex.Distributed.rpc(node, A, :greet, [])
{:ok, "hi from slave1@127.0.0.1"}

Link to this section Summary

Functions

down()

Stops the distributed environment and all slaves.

load_module(node, module)

Load the given module on the remote node.

load_object_code(node, module, object_code)

Load the given object code into module, file on the remote node.

rpc(node, module, function, args)

Remote procedure call on the given remote node.

rpc!(node, module, function, args)

Remote procedure call on the given remote node. Raise on badrpc.

setup_master(master_sname \\ "master", ip \\ "127.0.0.1")

Starts :net_kernel, :erl_boot_server.

slaves()

List all nodes that have been started by Nodex.Distributed.

spawn_epmd()

Start an instance of the erlang port mapper daemon.

spawn_slave(node)

Spawn a slave.

spawn_slaves(num_nodes, ip \\ "127.0.0.1")

Spawn a number of new slaves.

up(master_sname \\ "master", ip \\ "127.0.0.1")

Starts a distributed environment.

Link to this section Functions

down()

Specs

down() :: :ok

Stops the distributed environment and all slaves.

Stops :net_kernel and calls :slave.stop/1 on all connected nodes. It will spawn an instance of epmd (Erlang Port Mapper Daemon) and start :net_kernel.

load_module(node, module)

Specs

load_module(node(), module()) :: any()

Load the given module on the remote node.

load_object_code(node, module, object_code)

Specs

load_object_code(node(), module(), binary()) :: {:module, module()}

Load the given object code into module, file on the remote node.

Just a wrapper to call :code.load_binary/3 remotely.

rpc(node, module, function, args)

Specs

rpc(node(), module(), atom(), [any()]) :: {:ok, any()} | {:badrpc, any()}

Remote procedure call on the given remote node.

rpc!(node, module, function, args)

Specs

rpc!(node(), module(), atom(), [any()]) :: any()

Remote procedure call on the given remote node. Raise on badrpc.

setup_master(master_sname \\ "master", ip \\ "127.0.0.1")

Specs

setup_master(binary(), binary()) :: :ok

Starts :net_kernel, :erl_boot_server.

Adds the ip as a slave node to the list of allowed slave hosts. Optionally accepts an sname and ip as argument.

Parameters

sname: Provide a short name for this node. (default: "master")
ip: Provide an ip address for this node. (default: "127.0.0.1")

slaves()

Specs

slaves() :: [node()]

List all nodes that have been started by Nodex.Distributed.

Does not list other nodes connected to this node. For a list of all connected nodes use Node.list/0, or Node.list/1.

spawn_epmd()

Specs

spawn_epmd() :: {binary(), 0} | {binary(), integer()}

Start an instance of the erlang port mapper daemon.

It looks for the epmd executable using System.find_executable/1 (that looks into the PATH environment variable). Note, that epmd just exits if another instance of it is already running on the same host.

spawn_slave(node)

Specs

spawn_slave(node() | binary()) :: {:ok, node()}

Spawn a slave.

Add all code paths from this node, transfer elixir configuration and ensure all applications are started like on this node.

spawn_slaves(num_nodes, ip \\ "127.0.0.1")

Specs

spawn_slaves(integer(), binary()) :: [node()]

Spawn a number of new slaves.

Optionally accepts an ip as argument. Slaves are named "slave<index>", index starts at 1. Starting 2 slaves, starts two new nodes slave1@127.0.0.1 and slave2@127.0.0.1

See spawn_slave/1 for a description of what is loaded on the newly spawned node.

Returns a list of node identifiers that have been started.

up(master_sname \\ "master", ip \\ "127.0.0.1")

Specs

up(binary(), binary()) :: node()

Starts a distributed environment.

It will spawn an instance of epmd (Erlang Port Mapper Daemon) and start :net_kernel. Optionally accepts an sname and ip as argument.

Parameters

sname: Provide a short name for this node. (default: "master")
ip: Provide an ip this node should be listening on. (default: "127.0.0.1")