troposphere

About

troposphere - library to create AWS CloudFormation descriptions

The troposphere library allows for easier creation of the AWS CloudFormation JSON by writing Python code to describe the AWS resources. troposphere also includes some basic support for OpenStack resources via Heat.

To facilitate catching CloudFormation or JSON errors early the library has property and type checking built into the classes.

Installation

troposphere can be installed using the pip distribution system for Python by issuing:

$ pip install troposphere

To install troposphere with awacs (recommended soft dependency):

$ pip install troposphere[policy]

Alternatively, you can run use setup.py to install by cloning this repository and issuing:

$ python setup.py install  # you may need sudo depending on your python installation

Examples

A simple example to create an instance would look like this:

>>> from troposphere import Ref, Template
>>> import troposphere.ec2 as ec2
>>> t = Template()
>>> instance = ec2.Instance("myinstance")
>>> instance.ImageId = "ami-951945d0"
>>> instance.InstanceType = "t1.micro"
>>> t.add_resource(instance)
<troposphere.ec2.Instance object at 0x101bf3390>
>>> print(t.to_json())
{
    "Resources": {
        "myinstance": {
            "Properties": {
                "ImageId": "ami-951945d0",
                "InstanceType": "t1.micro"
            },
            "Type": "AWS::EC2::Instance"
        }
    }
}

A simple example to create an instance (YAML) would look like this:

>>> from troposphere import Ref, Template
>>> import troposphere.ec2 as ec2
>>> t = Template()
>>> instance = ec2.Instance("myinstance")
>>> instance.ImageId = "ami-951945d0"
>>> instance.InstanceType = "t1.micro"
>>> t.add_resource(instance)
<troposphere.ec2.Instance object at 0x101bf3390>
>>> print(t.to_yaml())

Resources:
    myinstance:
        Properties:
            ImageId: ami-951945d0
            InstanceType: t1.micro
        Type: AWS::EC2::Instance

Alternatively, parameters can be used instead of properties:

>>> instance = ec2.Instance("myinstance", ImageId="ami-951945d0", InstanceType="t1.micro")
>>> t.add_resource(instance)
<troposphere.ec2.Instance object at 0x101bf3550>

And add_resource() returns the object to make it easy to use with Ref():

>>> instance = t.add_resource(ec2.Instance("myinstance", ImageId="ami-951945d0", InstanceType="t1.micro"))
>>> Ref(instance)
<troposphere.Ref object at 0x101bf3490>

Examples of the error checking (full tracebacks removed for clarity):

Incorrect property being set on AWS resource:

>>> import troposphere.ec2 as ec2
>>> ec2.Instance("ec2instance", image="i-XXXX")
Traceback (most recent call last):
...
AttributeError: AWS::EC2::Instance object does not support attribute image

Incorrect type for AWS resource property:

>>> ec2.Instance("ec2instance", ImageId=1)
Traceback (most recent call last):
...
TypeError: ImageId is <type 'int'>, expected <type 'basestring'>

Missing required property for the AWS resource:

>>> from troposphere import Template
>>> import troposphere.ec2 as ec2
>>> t = Template()
>>> t.add_resource(ec2.Instance("ec2instance", InstanceType="m3.medium"))
<troposphere.ec2.Instance object at 0x109ee2e50>
>>> print(t.to_json())
Traceback (most recent call last):
...
ValueError: Resource ImageId required in type AWS::EC2::Instance

Currently supported AWS resource types

Currently supported OpenStack resource types

OS::Neutron::Firewall
OS::Neutron::FirewallPolicy
OS::Neutron::FirewallRule
OS::Neutron::FloatingIP
OS::Neutron::FloatingIPAssociation
OS::Neutron::HealthMonitor
OS::Neutron::Pool
OS::Neutron::LoadBalancer
OS::Neutron::Net
OS::Neutron::PoolMember
OS::Neutron::Port
OS::Neutron::SecurityGroup
OS::Nova::FloatingIP
OS::Nova::FloatingIPAssociation
OS::Nova::KeyPair
OS::Nova::Server

Todo:

Add additional validity checks

Duplicating a single instance sample would look like this

# Converted from EC2InstanceSample.template located at:
# http://aws.amazon.com/cloudformation/aws-cloudformation-templates/

from troposphere import Base64, FindInMap, GetAtt
from troposphere import Parameter, Output, Ref, Template
import troposphere.ec2 as ec2


template = Template()

keyname_param = template.add_parameter(Parameter(
    "KeyName",
    Description="Name of an existing EC2 KeyPair to enable SSH "
                "access to the instance",
    Type="String",
))

template.add_mapping('RegionMap', {
    "us-east-1":      {"AMI": "ami-7f418316"},
    "us-west-1":      {"AMI": "ami-951945d0"},
    "us-west-2":      {"AMI": "ami-16fd7026"},
    "eu-west-1":      {"AMI": "ami-24506250"},
    "sa-east-1":      {"AMI": "ami-3e3be423"},
    "ap-southeast-1": {"AMI": "ami-74dda626"},
    "ap-northeast-1": {"AMI": "ami-dcfa4edd"}
})

ec2_instance = template.add_resource(ec2.Instance(
    "Ec2Instance",
    ImageId=FindInMap("RegionMap", Ref("AWS::Region"), "AMI"),
    InstanceType="t1.micro",
    KeyName=Ref(keyname_param),
    SecurityGroups=["default"],
    UserData=Base64("80")
))

template.add_output([
    Output(
        "InstanceId",
        Description="InstanceId of the newly created EC2 instance",
        Value=Ref(ec2_instance),
    ),
    Output(
        "AZ",
        Description="Availability Zone of the newly created EC2 instance",
        Value=GetAtt(ec2_instance, "AvailabilityZone"),
    ),
    Output(
        "PublicIP",
        Description="Public IP address of the newly created EC2 instance",
        Value=GetAtt(ec2_instance, "PublicIp"),
    ),
    Output(
        "PrivateIP",
        Description="Private IP address of the newly created EC2 instance",
        Value=GetAtt(ec2_instance, "PrivateIp"),
    ),
    Output(
        "PublicDNS",
        Description="Public DNSName of the newly created EC2 instance",
        Value=GetAtt(ec2_instance, "PublicDnsName"),
    ),
    Output(
        "PrivateDNS",
        Description="Private DNSName of the newly created EC2 instance",
        Value=GetAtt(ec2_instance, "PrivateDnsName"),
    ),
])

print(template.to_json())

Community

We have a Google Group, cloudtools-dev, where you can ask questions and engage with the troposphere community. Issues and pull requests are always welcome!

Licensing

troposphere is licensed under the BSD 2-Clause license. See LICENSE for the troposphere full license text.

cwgem/troposphere