Sceptre is a tool to drive AWS CloudFormation. It automates away some of the more mundane, repetitive and error-prone tasks, allowing you to concentrate on building better infrastructure.
- Code reusability by separating a stack's template and its configuration
- Support for templates written in JSON, YAML or Python DSLs such as Troposphere
- Dependency resolution by passing of stack outputs to parameters of dependent stacks
- Environment support by bundling related stacks into logical groups (e.g. dev and prod)
- Environment-level commands, such as creating multiple stacks with a single command
- Fast, highly parallelised builds
- Built in support for working with stacks in multiple AWS accounts
- Infrastructure visibility with meta-operations such as stack querying protection
- Support for inserting dynamic values in templates via customisable resolvers
- Support for running arbitrary code as hooks before/after stack builds
Sceptre organises stacks into environments. Each stack is represented by a YAML configuration file stored in a directory which represents the environment. Here, we have two stacks,
subnets, in an environment named
$ tree . ├── config │ └── dev │ ├── config.yaml │ ├── subnets.yaml │ └── vpc.yaml └── templates ├── subnets.py └── vpc.py
We can create a stack with the
create-stack command. This
vpc stack contains a VPC:
$ sceptre create-stack dev vpc dev/vpc - Creating stack dev/vpc VirtualPrivateCloud AWS::EC2::VPC CREATE_IN_PROGRESS dev/vpc VirtualPrivateCloud AWS::EC2::VPC CREATE_COMPLETE dev/vpc sceptre-demo-dev-vpc AWS::CloudFormation::Stack CREATE_COMPLETE
subnets stack contains a subnet which must be created in the VPC. To do this, we need to pass the VPC ID, which is exposed as a stack output of the
vpc stack, to a parameter of the
subnets stack. Sceptre automatically resolves this dependency for us:
$ sceptre create-stack dev subnets dev/subnets - Creating stack dev/subnets Subnet AWS::EC2::Subnet CREATE_IN_PROGRESS dev/subnets Subnet AWS::EC2::Subnet CREATE_COMPLETE dev/subnets sceptre-demo-dev-subnets AWS::CloudFormation::Stack CREATE_COMPLETE
Sceptre implements meta-operations, which allow us to find out information about our stacks:
$ sceptre describe-env-resources dev dev/subnets: - LogicalResourceId: Subnet PhysicalResourceId: subnet-445e6e32 dev/vpc: - LogicalResourceId: VirtualPrivateCloud PhysicalResourceId: vpc-c4715da0
Sceptre provides environment-level commands. This one deletes the whole
dev environment. The subnet exists within the vpc, so it must be deleted first. Sceptre handles this automatically:
$ sceptre delete-env dev dev/subnets - Deleting stack dev/subnets Subnet AWS::EC2::Subnet DELETE_IN_PROGRESS dev/subnets - Stack deleted dev/vpc - Deleting stack dev/vpc VirtualPrivateCloud AWS::EC2::VPC DELETE_IN_PROGRESS dev/vpc - Stack deleted
Sceptre can be used from the CLI, or imported as a Python package.
Usage: sceptre [OPTIONS] COMMAND [ARGS]... Options: --version Show the version and exit. --debug Turn on debug logging. --dir TEXT Specify sceptre directory. --output [yaml|json] The formatting style for command output. --no-colour Turn off output colouring. --var TEXT A variable to template into config files. --var-file FILENAME A YAML file of variables to template into config files. --help Show this message and exit. Commands: continue-update-rollback Roll stack back to working state. create-change-set Creates a change set. create-stack Creates the stack. delete-change-set Delete the change set. delete-env Delete all stacks. delete-stack Delete the stack. describe-change-set Describe the change set. describe-env Describe the stack statuses. describe-env-resources Describe the env's resources. describe-stack-outputs Describe stack outputs. describe-stack-resources Describe the stack's resources. execute-change-set Execute the change set. generate-template Display the template used. get-stack-policy Display the stack policy used. launch-env Creates or updates all stacks. launch-stack Create or launch the stack. list-change-sets List change sets. lock-stack Prevent stack updates. set-stack-policy Set stack policy. unlock-stack Allow stack updates. update-stack Update the stack. update-stack-cs Update the stack via change set. validate-template Validate the template.
from sceptre.environment import Environment env = Environment("/path/to/sceptre_dir", "environment_name") stack = env.stacks["stack_name"] stack.create()
A full API description of the sceptre package can be found in the Documentation.
$ pip install sceptre
Tutorial and Documentation
See our Contributing Guide.