morp 1.0.1

Send and receive messages without thinking about it

Send messages without really thinking about it. Currently works with Amazon’s SQS.

1 Minute Getting Started

Send and receive a Foo message.

First, let’s set our environment variable:

export MORP_DSN=morp.interface.sqs.SQS://AWS_ID:AWS_KEY@

Second, let’s create a Foo class:

import morp

class Foo(morp.Message):
    def target(self):
        # this will be run when a message is consumed
        print(self.fields)

Third, let’s start our message consumer

$ morp --quiet

Fourth, let’s send a message:

f = Foo()
f.some_field = 1
f.some_other_field = 2
f.send()

And we’re done, take a look in the example folder for the actual code.

DSN

You configure your connection using a dsn in the form:

InterfaceName://username:password@?param1=value1&param2=value2

So, to connect to SQS, you would do:

morp.interface.sqs.SQS://AWS_ID:AWS_KEY@

You can also override some default values like region and read_lock:

morp.interface.sqs.SQS://AWS_ID:AWS_KEY@?region=us-west-1&read_lock=120

Encryption

If you would like to encrypt all your messages, you can pass in a key or keyfile argument to your dsn that either contains a key or a path to a key file and Morp will take care of encrypting and decrypting the messages for you transparently.

If we just want to have a key, let’s just modify our dsn:

morp.interface.sqs.SQS://AWS_ID:AWS_KEY@?key=jy4XWRuEsrH98RD2VeLG62uVLCPWpdUh

To use a keyfile, let’s first generate a key file:

openssl rand -base64 256 > /tmp/keyfile.key

And modify our dsn:

morp.interface.sqs.SQS://AWS_ID:AWS_KEY@?keyfile=/tmp/keyfile.key

That’s it, every message will now be encrypted on send and decrypted on receive.

Environment configuration

MORP_DISABLED

By default every message will be sent, if you just want to test functionality without actually sending the message you can set this environment variable to turn off all the queues.

MORP_DISABLED = 1 # queue is off
MORP_DISABLED = 0 # queue is on

MORP_PREFIX

By default, the queue name is just the class name, but if you would like to have that prefixed with something (eg, prod or dev) then you can set this environment variable and it will be prefixed to the queue name.

MORP_DSN

If you set the environment variable MORP_DSN with your connection dsn, morp will automatically configure itself on first import.

FAQ

I would like to have multiple queues

By default, Morp will send any message from any morp.Message derived class to Message.get_name(), you can override this behavior by giving your child class a .name attribute:

class childMsg(morp.Message):
    name = "custom-queue-name"

Now, you can have the Morp command line consumer read from that queue instead:

$ morp --quiet="" custom-queue-name

Installation

Use pip:

pip install morp