defmodule AMQP.Connection do
@moduledoc """
Functions to operate on Connections.
"""
import AMQP.Core
alias AMQP.Connection
defstruct [:pid]
@type t :: %Connection{pid: pid}
@doc """
Opens a new connection.
Behaves like `open/2` but takes only either AMQP URI or options.
## Examples
iex> options = [host: "localhost", port: 5672, virtual_host: "/", username: "guest", password: "guest"]
iex> AMQP.Connection.open(options)
{:ok, %AMQP.Connection{}}
iex> AMQP.Connection.open("amqp://guest:guest@localhost")
{:ok, %AMQP.Connection{}}
"""
@spec open(keyword | String.t()) :: {:ok, t()} | {:error, atom()} | {:error, any()}
def open(uri_or_options \\ []) when is_binary(uri_or_options) or is_list(uri_or_options) do
open(uri_or_options, :undefined)
end
@doc """
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.
## Options
* `:username` - The name of a user registered with the broker (default
`"guest"`)
* `:password` - The password of user (default to `"guest"`)
* `:virtual_host` - The name of a virtual host in the broker (defaults
`"/"`)
* `:host` - The hostname of the broker (default `"localhost"`)
* `:port` - The port the broker is listening on (default `5672`)
* `:channel_max` - The channel_max handshake parameter (default `0`)
* `:frame_max` - The frame_max handshake parameter (defaults `0`)
* `:heartbeat` - The hearbeat interval in seconds (defaults `10`)
* `:connection_timeout` - The connection timeout in milliseconds (efaults
`50000`)
* `:ssl_options` - Enable SSL by setting the location to cert files
(default `:none`)
* `:client_properties` - A list of extra client properties to be sent to
the server (default `[]`)
* `: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
* `:auth_mechanisms` - A list of authentication of SASL authentication
mechanisms to use. See
https://www.rabbitmq.com/access-control.html#mechanisms and
https://github.com/rabbitmq/rabbitmq-auth-mechanism-ssl for descriptions of
the available options
* `:name` - A human-readable string that will be displayed in the
management UI. Connection names do not have to be unique and cannot be
used as connection identifiers (default `:undefined`)
## Examples
iex> options = [host: "localhost", port: 5672, virtual_host: "/", username: "guest", password: "guest", name: "my-conn"]
iex> AMQP.Connection.open(options)
{:ok, %AMQP.Connection{}}
iex> AMQP.Connection.open("amqp://guest:guest@localhost", port: 5673)
{:ok, %AMQP.Connection{}}
## 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
Here is an example:
iex> 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
]
)
## Backward compatibility for connection name
RabbitMQ supports user-specified connection names since version 3.6.2.
Previously AMQP took a connection name as a separate parameter on `open/2`
and `open/3` and it is still supported in this version.
iex> options = [host: "localhost", port: 5672, virtual_host: "/", username: "guest", password: "guest"]
iex> AMQP.Connection.open(options, :undefined)
{:ok, %AMQP.Connection{}}
iex> AMQP.Connection.open("amqp://guest:guest@localhost", "my-connection")
{:ok, %AMQP.Connection{}}
iex> AMQP.Connection.open("amqp://guest:guest@localhost", "my-connection", options)
{:ok, %AMQP.Connection{}}
However the connection name parameter is now deprecated and might not be
supported in the future versions.
You are recommended to pass it with `:name` option instead:
iex> AMQP.Connection.open("amqp://guest:guest@localhost", name: "my-connection")
{:ok, %AMQP.Connection{}}
"""
@spec open(String.t() | keyword, keyword | String.t() | :undefined) ::
{:ok, t()} | {:error, atom()} | {:error, any()}
def open(uri, options)
def open(uri, name) when is_binary(uri) and (is_binary(name) or name == :undefined) do
do_open(uri, name, _options = [])
end
def open(options, name) when is_list(options) and (is_binary(name) or name == :undefined) do
{name_from_opts, options} = take_connection_name(options)
name = if name == :undefined, do: name_from_opts, else: name
options
|> merge_options_to_default()
|> do_open(name)
end
def open(uri, options) when is_binary(uri) and is_list(options) do
{name, options} = take_connection_name(options)
do_open(uri, name, options)
end
@doc false
@deprecated "Use :name in open/2 instead"
@spec open(String.t(), String.t() | :undefined, keyword) ::
{:ok, t()} | {:error, atom()} | {:error, any()}
def open(uri, name, options) when is_binary(uri) and is_list(options) do
do_open(uri, name, options)
end
defp do_open(uri, name, options) do
case uri |> String.to_charlist() |> :amqp_uri.parse() do
{:ok, amqp_params} -> amqp_params |> merge_options_to_amqp_params(options) |> do_open(name)
error -> error
end
end
defp do_open(amqp_params, name) do
case :amqp_connection.start(amqp_params, name) do
{:ok, pid} -> {:ok, %Connection{pid: pid}}
error -> error
end
end
# take name from options
defp take_connection_name(options) do
name = options[:name] || :undefined
options = Keyword.delete(options, :name)
{name, options}
end
@doc false
@spec merge_options_to_amqp_params(tuple, keyword) :: tuple
def merge_options_to_amqp_params(amqp_params, options) do
options = normalize_ssl_options(options)
params = amqp_params_network(amqp_params)
amqp_params_network(
username: keys_get(options, params, :username),
password: keys_get(options, params, :password),
virtual_host: keys_get(options, params, :virtual_host),
host: keys_get(options, params, :host) |> to_charlist(),
port: keys_get(options, params, :port) |> normalize_int_opt(),
channel_max: keys_get(options, params, :channel_max) |> normalize_int_opt(),
frame_max: keys_get(options, params, :frame_max) |> normalize_int_opt(),
heartbeat: keys_get(options, params, :heartbeat) |> normalize_int_opt(),
connection_timeout: keys_get(options, params, :connection_timeout) |> normalize_int_opt(),
ssl_options: keys_get(options, params, :ssl_options),
client_properties: keys_get(options, params, :client_properties),
socket_options: keys_get(options, params, :socket_options),
auth_mechanisms: keys_get(options, params, :auth_mechanisms)
)
end
# Gets the value from k1. If empty, gets the value from k2.
defp keys_get(k1, k2, key) do
Keyword.get(k1, key, Keyword.get(k2, key))
end
defp merge_options_to_default(options) do
amqp_params_network(
username: Keyword.get(options, :username, "guest"),
password: Keyword.get(options, :password, "guest"),
virtual_host: Keyword.get(options, :virtual_host, "/"),
host: Keyword.get(options, :host, 'localhost') |> to_charlist(),
port: Keyword.get(options, :port, :undefined) |> normalize_int_opt(),
channel_max: Keyword.get(options, :channel_max, 0) |> normalize_int_opt(),
frame_max: Keyword.get(options, :frame_max, 0) |> normalize_int_opt(),
heartbeat: Keyword.get(options, :heartbeat, 10) |> normalize_int_opt(),
connection_timeout: Keyword.get(options, :connection_timeout, 50000) |> normalize_int_opt(),
ssl_options: Keyword.get(options, :ssl_options, :none),
client_properties: Keyword.get(options, :client_properties, []),
socket_options: Keyword.get(options, :socket_options, []),
auth_mechanisms:
Keyword.get(options, :auth_mechanisms, [
&:amqp_auth_mechanisms.plain/3,
&:amqp_auth_mechanisms.amqplain/3
])
)
end
# If an integer value is configured as a string, cast it to an integer where
# applicable
defp normalize_int_opt(value) when is_binary(value), do: String.to_integer(value)
defp normalize_int_opt(value), do: value
@doc """
Closes an open Connection.
"""
@spec close(t) :: :ok | {:error, any}
def close(conn) do
case :amqp_connection.close(conn.pid) do
:ok -> :ok
error -> {:error, error}
end
end
defp normalize_ssl_options(options) when is_list(options) do
for {k, v} <- options do
if k in [:cacertfile, :certfile, :keyfile] do
{k, to_charlist(v)}
else
{k, v}
end
end
end
defp normalize_ssl_options(options), do: options
end
