Defender as Code Serverless Plugin

Defender as Code (DaC) is a Serverless Framework plugin for automated resource management and configuration as code.

:warning: This plugin is under development and behavior might change. Handle with care.

Prerequisites

Serverless Framework: https://www.serverless.com/framework/docs/getting-started/

Installation

You can initialise your Serverless project directly using our pre-configured template:

sls install --url https://github.com/OpenZeppelin/defender-as-code/tree/main/template -n my-service

Note: for the command above to work correctly you need access to this repo.

Alternatively, you can install it directly into an existing project with:

yarn add @openzeppelin/defender-as-code

Setup

There are a few ways you can set up the serverless.yml configuration:

• Create it from scratch;
• Use Defender's 2.0 Serverless export capability;
• Leverage the example template provided in the defender-as-code repository.

If you already have resources such as contracts, notifications, relayers, actions, etc. in Defender 2.0, you can export a serverless.yml configuration file containing these resources from the manage → advanced page.

NOTE: If you have previously deployed with defender-as-code to the same account and subsequently created new resources through the Defender 2.0 user interface, the export function will automatically assign a stackResourceId to the new resources based on the name of your latest deployment stack. If you have not deployed using defender-as-code before, a default stack name of mystack will be used.

This plugin allows you to define Actions, Monitors, Notifications, Categories, Relayers, Contracts, Policies and Secrets declaratively from a serverless.yml and provision them via the CLI using serverless deploy. An example template below with an action, a relayer, a policy and a single relayer API key defined:

service: defender-serverless-template
configValidationMode: error
frameworkVersion: '3'

provider:
  name: defender
  stage: ${opt:stage, 'dev'}
  stackName: 'mystack'
  ssot: false

defender:
  key: '${env:TEAM_API_KEY}'
  secret: '${env:TEAM_API_SECRET}'

resources:
  actions:
    action-example-1:
      name: 'Hello world from serverless'
      path: './actions/hello-world'
      relayer: ${self:resources.relayers.relayer-1}
      trigger:
        type: 'schedule'
        frequency: 1500
      paused: false
      # optional - unencrypted and scoped to the individual action
      environment-variables:
        hello: 'world!'
    action-example-2: 2cbc3f58-d962-4be8-a158-1035be4b661c

  policies:
    policy-1:
      gas-price-cap: 1000
      whitelist-receivers:
        - '0x0f06aB75c7DD497981b75CD82F6566e3a5CAd8f2'
      eip1559-pricing: true

  relayers:
    relayer-1:
      name: 'Test Relayer 1'
      network: 'sepolia'
      min-balance: 1000
      policy: ${self:resources.policies.policy-1}
      api-keys:
        - key1

plugins:
  - '@openzeppelin/defender-as-code'

This requires setting the key and secret under the defender property of the YAML file. We recommend using environment variables or a secure (gitignored) configuration file to retrieve these values. Modify the serverless.yml accordingly.

Ensure the Defender Team API Keys are setup with all appropriate API capabilities.

The stackName (e.g. mystack) is combined with the resource key (e.g. relayer-1) to uniquely identify each resource. This identifier is called the stackResourceId (e.g. mystack.relayer-1) and allows you to manage multiple deployments within the same tenant.

You may also reference existing Defender resources directly by their unique ID (e.g. 2cbc3f58-d962-4be8-a158-1035be4b661c). These resources will not be managed by the plugin and will be ignored during the deploy process. However, you may reference them in other resources to update their configuration accordingly. A list of properties that support direct referencing:

• relayer may reference a relayerId in Actions
• action-trigger may reference an actionid in Monitor
• action-condition may reference an actionId in Monitor
• address-from-relayer may reference a relayerId in Relayer
• notify-config.channels may reference multiple notificationId in Monitor
• contracts may be used over addresses and reference multiple contractId in Monitor The following is an example of how a direct reference to a Defender contract and relayer can be used in monitor and action respectively:

...
contracts:
  contract-1: 'sepolia-0x62034459131329bE4349A9cc322B03c63806Aa11' # contractId of an existing resource in Defender
relayers:
  relayer-2: 'bcb659c6-7e11-4d37-a15b-0fa9f3d3442c' # relayerId of an existing relayer in Defender
actions:
  action-example-1:
    name: 'Hello world from serverless'
    path: './actions/hello-world'
    relayer: ${self:resources.relayers.relayer-2}
    trigger:
      type: 'schedule'
      frequency: 1500
    paused: false
monitors:
  block-example:
    name: 'Block Example'
    type: 'BLOCK'
    network: 'sepolia'
    risk-category: 'TECHNICAL'
    # optional - either contracts OR addresses should be defined
    contracts:
      - ${self:resources.contracts.contract-1}
    ...
...

SSOT mode

Under the provider property in the serverless.yml file, you can optionally add a ssot boolean. SSOT or Single Source of Truth, ensures that the state of your stack in Defender is perfectly in sync with the serverless.yml template. This means that all Defender resources, that are not defined in your current template file, are removed from Defender, with the exception of Relayers, upon deployment. If SSOT is not defined in the template, it will default to false.

Any resource removed from the serverless.yml file does not get automatically deleted in order to prevent inadvertent resource deletion. For this behaviour to be anticipated, SSOT mode must be enabled.

Block Explorer Api Keys

Exported serverless configurations with Block Explorer Api Keys will not contain the key field but instead a key-hash field which is a keccak256 hash of the key. This must be replaced with the actual key field (and key-hash removed) before deploying

Secrets (Action)

Action secrets can be defined both globally and per stack. Secrets defined under global are not affected by changes to the stackName and will retain when redeployed under a new stack. Secrets defined under stack will be removed (on the condition that SSOT mode is enabled) when the stack is redeployed under a new stackName. To reference secrets defined under stack, use the following format: <stackname>_<secretkey>, for example mystack_test.

secrets:
  # optional - global secrets are not affected by stackName changes
  global:
    foo: ${self:custom.config.secrets.foo}
    hello: ${self:custom.config.secrets.hello}
  # optional - stack secrets (formatted as <stackname>_<secretkey>)
  stack:
    test: ${self:custom.config.secrets.test}

Types and Schema validation

We provide auto-generated documentation based on the JSON schemas:

• Defender Property
• Provider Property
• Resources Property

More information on types can be found here. Specifically, the types preceded with Y (e.g. YRelayer). For the schemas, you can check out the docs-schema folder.

Additionally, an example project is available which provides majority of properties that can be defined in the serverless.yml file.

Commands

Deploy

You can use sls deploy to deploy your current stack to Defender.

The deploy takes in an optional --stage flag, which is defaulted to dev when installed from the template above.

Moreover, the serverless.yml may contain an ssot property. More information can be found in the SSOT mode section.

This command will append a log entry in the .defender folder of the current working directory. Additionally, if any new relayer keys are created, these will be stored as JSON objects in the .defender/relayer-keys folder.

When installed from the template, we ensure the .defender folder is ignored from any git commits. However, when installing directly, make sure to add this folder it your .gitignore file.

Info

You can use sls info to retrieve information on every resource defined in the serverless.yml file, including unique identifiers, and properties unique to each Defender component.

Remove

You can use sls remove to remove all Defender resources defined in the serverless.yml file.

To avoid potential loss of funds, Relayers can only be deleted from the Defender UI directly.

Logs

You can use sls logs --function <stack_resource_id> to retrieve the latest action logs for a given action identifier (e.g. mystack.action-example-1). This command will run continiously and retrieve logs every 2 seconds.

Invoke

You can use sls invoke --function <stack_resource_id> to manually run an action, given its identifier (e.g. mystack.action-example-1).

Each command has a standard output to a JSON object.

More information can be found on our documentation page here

Caveats

Errors thrown during the deploy process, will not revert any prior changes. Common errors are:

• Not having set the API key and secret
• Insufficient permissions for the API key
• Validation error of the serverless.yml file (see Types and Schema validation)

Usually, fixing the error and retrying the deploy should suffice as any existing resources will fall within the update clause of the deployment. However, if unsure, you can always call sls remove to remove the entire stack, and retry.

Action secrets are encrypted key-value pairs and injected at runtime into the lambda environment. Secrets are scoped to all actions automatically. Alternatively, you may use environment-variables to define key-value pairs that are scoped to the individual action, and available at runtime through process.env. Note that these values are not encrypted.

Publish a new release

npm login
git checkout main
git pull origin main
# increment version in package.json
npm publish
git add package.json
git commit -m 'v{version here}'
git push origin main