Paws - A Perl SDK for AWS (Amazon Web Services) APIs
use Paws; my $obj = Paws->service('...'); my $res = $obj->MethodCall(Arg1 => $val1, Arg2 => $val2); print $res->AttributeFromResult;
Paws is an attempt to develop an always up-to-date SDK that covers all possible AWS services.
Please consider the SDK is beta quality. The intention of publishing to CPAN is having the community find the SDK, try it, give feedback, etc. Some services are still not working, and some heavy refactoring will still be done to the internals. The external interface to SDK users will try to be kept stable, and changes to it should be notified via ChangeLog
Paws::ApiGateway
Paws::AutoScaling
Paws::CloudFormation
Paws::CloudFront
Paws::CloudHSM
Paws::CloudSearch
Paws::CloudSearchDomain
Paws::CloudTrail
Paws::CloudWatch
Paws::CloudWatchLogs
Paws::CodeCommit
Paws::CodeDeploy
Paws::CodePipeline
Paws::CognitoIdentity
Paws::CognitoSync
Paws::Config
Paws::DataPipeline
Paws::DeviceFarm
Paws::DirectConnect
Paws::DS
Paws::DynamoDB
Paws::DynamoDBStreams
Paws::EC2
Paws::ECS
Paws::EFS
Paws::ElastiCache
Paws::ElasticBeanstalk
Paws::ElasticTranscoder
Paws::ELB
Paws::EMR
Paws::ES
Paws::Firehose
Paws::Glacier
Paws::IAM
Paws::ImportExport
Paws::Inspector
Paws::IoT
Paws::IoTData
Paws::Kinesis
Paws::KMS
Paws::Lambda
Paws::MachineLearning
Paws::MarketplaceCommerceAnalytics
Paws::OpsWorks
Paws::RDS
Paws::RedShift
Paws::Route53
Paws::Route53Domains
Paws::S3
Paws::SDB
Paws::SES
Paws::Signin
Paws::SimpleDB
Paws::SimpleWorkflow
Paws::SNS
Paws::SQS
Paws::SSM
Paws::StorageGateway
Paws::STS
Paws::Support
Paws::WAF
Paws::WorkSpaces
Each service in AWS (EC2, CloudFormation, SQS, SNS, etc) has a service class. The service class represents the properties that a web service has (how to call it, what methods it has, how to authenticate, etc). When a service class is instantiated with the right properties (region, if needed, credentials, caller, etc), it will be able to make calls to the service.
Service classes are obtained through
my $service_class = Paws->class_for_service('Service'); my $service_object = $service_class->new(region => '...', caller => ...)
Although they are seldom needed. 99% of the time you want service objects directly obtained with the ->service method (read next section) since you have to write less code.
Each Service Object represents the ability to call methods on a service endpoint. Those endpoints are either global, or bound to a region depending on the service. Also, each object can be customized with a credential provider, that tells the object where to obtain credentials for the call (you can get them from the environment, from the filesystem, from the AWS Instance Profile, STS, etc.
To obtain a service object, call the ->service method
->service
use Paws; my $service = Paws->service('Service');
You can pass extra parameters if the service is bound to a region:
my $service = Paws->service('Service', region => 'us-east-1');
These parameters are basically passed to the service class constructor
Service classes by default try to authenticate with a chained authenticator. The chained authenticator tries to first find credentials in your environment variables AWS_ACCESS_KEY and AWS_SECRET_KEY (note that AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY are also scanned for compatibility with the official SDKs). Second, it will look for credentials in the default profile of the ~/.aws/credentials or the file in AWS_CONFIG_FILE env variable (an ini-formatted file). Last, if no environment variables are found, then a call to retrieve Role credentials is done. If your instance is running on an AWS instance, and has a Role assigned, the SDK will automatically retrieve credentials to call any services that the instances Role permits.
Please never burn credentials into your code. That's why the methods for passing an explicit access key and secret key are not documented.
So, instantiating a service with
my $ec2 = Paws->service('EC2', region => 'eu-west-1');
we get an service object that will try to authenticate with environment, credential file, or an instance role.
When instantiating a service object, you can also pass a custom credential provider:
use Paws::Credential::STS; my $cred_provider = Paws::Credential::STS->new( Name => 'MyName', DurationSeconds => 900, Policy => '{"Version":"2012-10-17","Statement":[{"Effect": "Allow","Action":["ec2:DescribeInstances"],"Resource":"*"}]}' ); my $ec2 = Paws->service('EC2', credentials => $cred_provider, region => 'eu-west-1');
In this example we instance a service object that uses the STS service to create temporary credentials that only let the service object call DescribeInstances.
Each API call is represented as a method call with the same name as the API call. The arguments to the call are passed as lists (named parameters) to the call. So, to call DescribeInstances on the EC2 service:
my $result = $ec2->DescribeInstances;
The DescribeInstances call has no required parameters, but if needed, we can pass them in (you can look them up in Paws::EC2 and see detail in Paws::EC2::DescribeInstances
my $result = $ec2->DescribeInstances(MaxResults => 5);
If the parameter is an Array:
my $result = $ec2->DescribeInstances(InstanceIds => [ 'i-....' ]);
If the parameter to be passed in is a complex value (an object)
my $result = $ec2->DescribeInstances(Filters => [ { Name => '', Value => '' } ])
The AWS APIs return nested datastructures in various formats. The SDK converts these datastructures into objects that can then be used as wanted.
my $private_dns = $result->Reservations->[0]->Instances->[0]->PrivateDnsName;
Paws instances have a configuration. The configuration is basically a specification of values that will be passed to the service method each time it's called
# the credentials and the caller keys accept an instance or the name of a class as a # string (the class will be loaded and the constructor of that class will be automatically called my $paws1 = Paws->new(config => { credentials => MyCredProvider->new, region => 'eu-west-1' }); my $paws2 = Paws->new(config => { caller => 'MyCustomCaller' }); # EC2 service with MyCredProvider in eu-west-1 my $ec2 = $paws1->service('EC2'); # DynamoDB service with MyCustomCaller in us-east-1. region is needed because it's not in the config my $ddb = $paws2->service('DynamoDB', region => 'us-east-1'); # DynamoDB in eu-west-1 with MyCredProvider my $other_ddb = $paws1->service('DynamoDB');
The attributes that can be configured are:
Accepts a string which value is the name of a class, or an already instantiated object. If a string is passed, the class will be loaded, and the constructor called (without parameters). Also, the resulting instance or the already instantiated object has to have the Paws::Credential role.
Accepts a string which value is the name of a class, or an already instantiated object. If a string is passed, the class will be loaded, and the constructor called (without parameters). Also, the resulting instance or the already instantiated object has to have the Paws::Net::CallerRole role.
A string representing the region that service objects will be instantiated with. Default value is undefined, meaning that you will have to specify the desired region every time you call the service method.
Credential classes need to have the Role Paws::Credential applied. This obliges them to implement access_key, secret_key and session_token methods. The obtention of this data can be customized to be retrieved whereever the developer considers useful (files, environment, other services, etc). Take a look at the Paws::Credential::XXXX namespace to find already implemented credential providers.
The credential objects' access_key, secret_key and session_token methods will be called each time an API call has to be signed.
Caller classes need to have the Role Paws::Net::CallerRole applied. This obliges them to implement the do_call method. Tests use this interface to mock calls and responses to the APIs (without using the network).
The caller instance is responsable for doing the network Input/Output with some type of HTTP request library, and returning the Result from the API.
These callers are included and supported in Paws:
Paws::Net::Caller: Uses HTTP::Tiny. It's the default caller for Paws
Paws::Net::MojoAsyncCaller: Experimental asyncronous IO caller. Paws method calls return futures instead of results
Paws::Net::LWPCaller: Uses LWP. LWP supports HTTPS proxies, so Paws can call AWS from behind an HTTPS proxy.
Paws::Net::FurlCaller: Uses Furl: a lightning fast HTTP client
Paws->preload_service($service) Paws->preload_service($service, @methods)
Paws manages a lot of objects that are loaded dynamically as needed. This causes high memory consumption if you do operations with Paws in a forked environment because each child loads a separate copy of all the classes it needs to do the calls. Paws provides the preload_service operation. Call it with the name of the service before forking off so your server can benefit from copy on write memory sharing. The parent class will load all the classes needed so that child processes don't need to load them.
Some classes have lot's of calls, so preloading them can be quite expensive. If you call preload_service with a list of the methods you will call, it will only load classes needed for those calls. This is specially useful for Paws::EC2, for example.
Preloading doesn't change the usage of Paws. That means that all services and methods still work without any change, just that if they're not preloaded they'll be loaded at runtime.
Paws objects are programmed with Moose (the Modern Perl Object Framework). Moose objects can be immutibilized so that method calls perform better, at the cost of startup time. If you deem your usage of Paws to be long-lived, you can call
Paws->default_config->immutable(1);
as early as possible in the code. Very important that the immutable flag be activated before calling preload_service.
Jose Luis Martinez CPAN ID: JLMARTIN CAPSiDE jlmartinez@capside.com
http://aws.amazon.com/documentation/
https://github.com/pplu/aws-sdk-perl
The source code is located here: https://github.com/pplu/aws-sdk-perl
Please report bugs to: https://github.com/pplu/aws-sdk-perl/issues
Copyright (c) 2015 by Jose Luis Martinez Torres
This code is distributed under the Apache 2 License. The full text of the license can be found in the LICENSE file included with this module.
Luis Alberto Gimenez (@agimenez) for - The git-fu cleaning up the "pull other sdks" code - Credential Providers code - Fixes for users that have no HOME env variable - FileCaller to fully mock responses
Srinvas (@kidambisrinivas) for testing, bug reporting and fixing
juair10 for corrections and testing
CHORNY for CPAN and cpanfile packaging corrections
Iñigo Tejedor for service endpoint resolution based on rules
codehead for helping fix SQS Queue Maps
mbartold for helping fix SQS MessageBatch functionality
coreymayer for reporting bug in RestXmlCaller
arc (Aaron Crane) for documentation patches
dtikhonov for LWP Caller and bug reporting/fixing
vivus-ignis for DynamoDB bug reporting and test scripts for DynamoDB
karenetheridge for bug reporting, pull requests and help
ioanrogers for fixing unicode issues in tests
ilmari for fixing issues with timestamps in Date and X-Amz-Date headers
stevecaldwell77 for contributing support for temporary credentials in S3
Gimpson for contributing documentation fixes
Roger Pettett for testing and contributing fixes for tests on MacOSX
Henri Yandell for help with licensing issues
Oriol Soriano (@ureesoriano) for contribution to API builders
H. Daniel Cesario (@maneta) for devel setup instructions on RH and MacOSX
Glen van Ginkel for contributions to get S3 working
To install Paws::SDK::Config, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Paws::SDK::Config
CPAN shell
perl -MCPAN -e shell install Paws::SDK::Config
For more information on module installation, please visit the detailed CPAN module installation guide.