CDK - Lambda Function to start/stop ECS services

scheduler-fnc-cdk.js

// In the Scheduler Stack ===========================================
// Lambda Function to start/stop tasks
const ecsScheduleFnc = new Function(this, 'ecsScheduleFnc', {
    description: 'Lambda ECS Service Mgt Function',
    functionName: 'ecsScheduleFnc',
    runtime: Runtime.NODEJS_14_X,
    handler: 'index.handler',
    timeout: Duration.seconds(5),
    code: Code.fromAsset(`${__dirname}/lambda/manage-task`),
});

// IAM Policy to allow access to ECS Services from Lambda
ecsScheduleFnc.addToRolePolicy(new iam.PolicyStatement({
    sid: 'ECSServices',
    resources: ['*'],
    actions: [
        'ecs:ListServices',
        'ecs:ListClusters',
    ],
}));
// IAM Policy to allow Start/Stop of the demo services
ecsScheduleFnc.addToRolePolicy(new iam.PolicyStatement({
    sid: 'DemoApp',
    // Allow access to all ECS tasks - not production ready
    // Alternatives include using Tags or prefixes, or moving this policy add to the app stacks themselves
    resources: ['*'],
    actions: [
        'ecs:UpdateService',
        'ecs:DescribeServices',
    ],
}));

// In the Application Stack =====================================
// Lambda target config
const params = {
    clusterArn: cluster.clusterArn,
    serviceName: service.serviceName,
};

// Schedule Rules
params.active = true; // Start
const mgtTarget = new LambdaFunction(ecsScheduleFnc, {
    event: RuleTargetInput.fromObject({ params }),
    retryAttempts: 3,
});
const startRule = new Rule(this, 'startRule', {
    description: 'Start ECS Task',
    schedule: Schedule.expression(`cron('0 2 ? * MON-FRI *')`), // UTC, seconds not supported
});
startRule.addTarget(mgtTarget);