AWS::SNS::Notification
Description of an AWS Simple Notification Service message.
Synopsis
use Cro::HTTP::Router;
use Cro::HTTP::Server;
use AWS::SNS::Notification;
my $app = route {
post -> 'sns-message' {
# The SNS message has a content-type of 'text/plain' so this will be raw JSON
request-body -> $json {
my $notification = AWS::SNS::Notification.from-json($json);
# Check this is a valid notification
if $notification.verify-signature {
if $notification.is-notification {
# Do something with the $notification.message
# The format of which depends on the source - an S3 notification will be a JSON String for instance
}
else {
# This is subscribe or unsubscribe confirmation request
# so perform the confirmation
$notification.respond;
}
}
else {
bad-request 'text/plain', 'Fake notification';
}
}
}
};
my Cro::Service $service = Cro::HTTP::Server.new(:host<127.0.0.1>, :port<7798>, application => $app);
$service.start;
react { whenever signal(SIGINT) { $service.stop; exit; } }
Alternatively you can derive a body parser using Cro::HTTP::BodyParser::JSONClass :
use Cro::HTTP::Router;
use Cro::HTTP::Server;
use AWS::SNS::Notification;
use Cro::HTTP::BodyParser::JSONClass;
class SNSBodyParser does Cro::HTTP::BodyParser::JSONClass[AWS::SNS::Notification] {
use Cro::HTTP::Message;
method is-applicable(Cro::HTTP::Message $message --> Bool ) {
$message.header('x-amz-sns-message-type').defined && $message.header('x-amz-sns-message-id').defined;
}
}
my $app = route {
body-parser SNSBodyParser;
post -> 'sns-message' {
request-body -> $notification {
# Check this is a valid notification
if $notification.verify-signature {
if $notification.is-notification {
# Do something with the $notification.message
# The format of which depends on the source - an S3 notification will be a JSON String for instance
}
else {
# This is subscribe or unsubscribe confirmation request
# so perform the confirmation
$notification.respond;
}
}
else {
bad-request 'text/plain', 'Fake notification';
}
}
}
};
my Cro::Service $service = Cro::HTTP::Server.new(:host<127.0.0.1>, :port<7798>, application => $app);
$service.start;
react { whenever signal(SIGINT) { $service.stop; exit; } }
Description
This class describes an AWS Simple Notification Service message that may be delivered by HTTPS or by a message queue or somesuch.
The class provides for parsing the JSON payload for the message, verifying the signature of the message against the signing key and responding if necessary to a Subscribe or Unsubscribe confirmation.
The actual message sent by the source application is accessed through the .message
accessor - so for instance in the case of an S3 notification this will be a JSON string which will need to be decoded for further processing.
Installation
Assuming you have a working rakudo installation you can install this with zef :
zef install AWS::SNS::Notification
Or from a local clone of the distribution
zef install AWS::SNS::Notification
Support
If you have an feedback/suggestions/patches please send them via Github
Licence and Copyright
This library is free software. Please see the LICENCE file in the distribution for details.
© Jonathan Stowe 2021