AWS CDK resource create sequence?

Question

I'm using the AWS CDK. When I deploy, according to CloudFormation Events in the AWS console, resources(CfnTrigger) in createWorkflow are initialized before createDDBCrawler and createS3Crawler. Which is causing create_failed(Entity not found) since createWorkflow depends on resources in these two.

So I am wondering:

AWS CDK resource generating sequence (since I see no async or promise in functions, so TypeScript is handling the code in sequence. Then it's a CDK/CloudFormation behavior?)
How to avoid this or arrange resource create sequence, except creating two stack.

export class QuicksightGlue extends Construct {

    constructor(scope: Construct, name: string, props: QuicksightGlueProps) {
        super(scope, name);
        this.createGlueDb(props.glueDb);

        for (let zone of zones) {

            const ddbCrawler = this.createDDBCrawler(...);

            const etlJob = this.createEtlJob(...);

            // crawler for processed data
            this.createS3Crawler(...);  

            // create workflow that use crawler
            this.createWorkflow(...);      
        }
    }

private createS3Crawler(...) {
        return new glue.CfnCrawler(this, 's3Crawler_' + zone, {
            name: 's3Crawler_' + zone,
            databaseName: glueDb,
            role: roleArn,
            targets: {
                s3Targets: [{ path: s3 }]
            }
        });
    }
private createWorkflow(...) {
        const extracDdbWorkflow = new glue.CfnWorkflow(this, `ExtractDdb_` + zone, {
            name: `udhcpExtractDdb_` + zone.toLowerCase(),
            description: "Workflow to extract and process data from DDB"
        });

        const scheduledTriggerDdbCrawler = new glue.CfnTrigger(this, 'DdbTrigger_' + zone, {
            workflowName: extracDdbWorkflow.name,
            type: "SCHEDULED",
            schedule: scheduleCronExpression, //"cron(0 * * * ? *)",
            description: "Trigger to start the workflow every hour to update ddb data",
            actions: [{
                crawlerName: ddbCrawler,
                }],
        });
...

Can you show the definition of createWorkflow and createS3Crawler? — user16442705

Unknown Unknown · Accepted Answer · 2021-07-30T17:23:32

You can cause a construct to become dependent on another construct by calling addDependency on the construct's node property, like this:

// Normally these two constructs would be created in parallel
const construct1 = ...;
const construct2 = ...;

// But with this line, construct2 will not be created until construct 1 is
construct2.node.addDependency(construct1);

Here is a practical example.

Probably, you'd want to save the return value of createS3Crawler to a variable, and then pass that variable as an argument to createWorkflow. Then, createWorkflow will call .node.addDependency(createS3Crawler) on each construct that it creates internally which is dependent on the S3 crawler.

AWS CDK resource create sequence?

1 Answers