amqp

v0.3.1

amqp v0.3.1 AMQP.Connection View Source

Functions to operate on Connections.

Link to this section Summary

Types

t()

Functions

close(conn)

Closes an open Connection

open(options \\ [])

Opens an new Connection to an AMQP broker

open_direct(options \\ [])

Opens an new direct Connection to an AMQP broker

Link to this section Types

Link to this type t() View Source 
t() :: %AMQP.Connection{pid: pid}

Link to this section Functions

Link to this function close(conn) View Source 
close(t) :: :ok | {:error, atom}

Closes an open Connection.

Link to this function open(options \\ []) View Source 
open(keyword | String.t) ::
  {:ok, t} |
  {:error, atom} |
  {:error, any}

Opens an new Connection to an AMQP broker.

The connections created by this module are supervised under amqp_client’s supervision tree. Please note that connections do not get restarted automatically by the supervision tree in case of a failure. If you need robust connections and channels, use monitors on the returned connection PID.

The connection parameters can be passed as a keyword list or as a AMQP URI.

When using a keyword list, the following options can be used:

Options

  • :username - The name of a user registered with the broker (defaults to “guest”);
  • :password - The password of user (defaults to “guest”);
  • :virtual_host - The name of a virtual host in the broker (defaults to “/“);
  • :host - The hostname of the broker (defaults to “localhost”);
  • :port - The port the broker is listening on (defaults to 5672);
  • :channel_max - The channel_max handshake parameter (defaults to 0);
  • :frame_max - The frame_max handshake parameter (defaults to 0);
  • :heartbeat - The hearbeat interval in seconds (defaults to 0 - turned off);
  • :connection_timeout - The connection timeout in milliseconds (defaults to infinity);
  • :ssl_options - Enable SSL by setting the location to cert files (defaults to none);
  • :client_properties - A list of extra client properties to be sent to the server, defaults to [];
  • :socket_options - Extra socket options. These are appended to the default options. See http://www.erlang.org/doc/man/inet.html#setopts-2 and http://www.erlang.org/doc/man/gen_tcp.html#connect-4 for descriptions of the available options.

Enabling SSL

To enable SSL, supply the following in the ssl_options field:

  • cacertfile - Specifies the certificates of the root Certificate Authorities that we wish to implicitly trust;
  • certfile - The client’s own certificate in PEM format;
  • keyfile - The client’s private key in PEM format;

Example 

AMQP.Connection.open port: 5671,
                     ssl_options: [cacertfile: '/path/to/testca/cacert.pem',
                                   certfile: '/path/to/client/cert.pem',
                                   keyfile: '/path/to/client/key.pem',
                                   # only necessary with intermediate CAs
                                   # depth: 2,
                                   verify: :verify_peer,
                                   fail_if_no_peer_cert: true]

Examples 

iex> AMQP.Connection.open host: "localhost", port: 5672, virtual_host: "/", username: "guest", password: "guest"
{:ok, %AMQP.Connection{}}

iex> AMQP.Connection.open "amqp://guest:guest@localhost"
{:ok, %AMQP.Connection{}}
Link to this function open_direct(options \\ []) View Source 
open_direct(keyword) :: {:ok, t} | {:error, atom}

Opens an new direct Connection to an AMQP broker.

Direct connection is the special type of connection that is supported by RabbitMQ broker, where Erlang distribution protocol is used to communicate with broker. It’s a bit faster than the regular AMQP protocol, as there is no need to serialize and deserialize AMQP frames (especially when we are using this library at the same BEAM node where the RabbitMQ runs). But it’s less secure, as giving direct access to a client means it has full control over RabbitMQ node.

The connections created by this function are not restaretd automatically, see open/1 for more details.

The connection parameters are passed as a keyword list with the following options available:

Options

  • :username - The name of a user registered with the broker (defaults to :none);
  • :password - The password of the user (defaults to :none);
  • :virtual_host - The name of a virtual host in the broker (defaults to “/“);
  • :node - Erlang node name to connect to (defaults to the current node);
  • :client_properties - A list of extra client properties to be sent to the server, defaults to [];

Adapter options

Additional details can be provided when a direct connection is used to provide connectivity for some non-AMQP protocol (like it happens in STOMP and MQTT plugins for RabbitMQ). We assume that you know what you are doing in this case, here is the options that maps to corresponding fields of #amqp_adapter_info{} record: :adapter_host, :adapter_port, :adapter_peer_host, :adapter_peer_port, :adapter_name, :adapter_protocol, :adapter_additional_info.

Examples 

AMQP.Connection.open_direct node: :rabbit@localhost
{:ok, %AMQP.Connection{}}