Pulumi Component

# Authoring Pulumi Components

A ComponentResource groups related infrastructure resources into a reusable, logical unit. Components make infrastructure easier to understand, reuse, and maintain. Components appear as a single node with children nested underneath in `pulumi preview`/`pulumi up` output and in the Pulumi Cloud console.

This skill covers the full component authoring lifecycle. For general Pulumi coding patterns (Output handling, secrets, aliases, preview workflows), use the `pulumi-best-practices` skill instead.

## When to Use This Skill

Invoke this skill when:

- Creating a new ComponentResource class
- Designing the args interface for a component
- Making a component consumable from multiple Pulumi languages
- Publishing or distributing a component package
- Refactoring inline resources into a reusable component
- Debugging component behavior (missing outputs, stuck creating, children at wrong level)

## Component Anatomy

Every component has four required elements:

1. **Extend ComponentResource** and call `super()` with a type URN
2. **Accept standard parameters**: name, args, and `ComponentResourceOptions`
3. **Set `parent: this`** on all child resources
4. **Call `registerOutputs()`** at the end of the constructor

### TypeScript

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as aws from "@pulumi/aws";

interface StaticSiteArgs {
    indexDocument?: pulumi.Input<string>;
    errorDocument?: pulumi.Input<string>;
}

class StaticSite extends pulumi.ComponentResource {
    public readonly bucketName: pulumi.Output<string>;
    public readonly websiteUrl: pulumi.Output<string>;

    constructor(name: string, args: StaticSiteArgs, opts?: pulumi.ComponentResourceOptions) {
        // 1. Call super with type URN: <package>:<module>:<type>
        super("myorg:index:StaticSite", name, {}, opts);

        // 2. Create child resources with parent: this
        const bucket = new aws.s3.Bucket(`${name}-bucket`, {}, { parent: this });

        const website = new aws.s3.BucketWebsiteConfigurationV2(`${name}-website`, {
            bucket: bucket.id,
            indexDocument: { suffix: args.indexDocument ?? "index.html" },
            errorDocument: { key: args.errorDocument ?? "error.html" },
        }, { parent: this });

        // 3. Expose outputs as class properties
        this.bucketName = bucket.id;
        this.websiteUrl = website.websiteEndpoint;

        // 4. Register outputs -- always the last line
        this.registerOutputs({
            bucketName: this.bucketName,
            websiteUrl: this.websiteUrl,
        });
    }
}

// Usage
const site = new StaticSite("marketing", {
    indexDocument: "index.html",
});
export const url = site.websiteUrl;
```

### Python

```python
import pulumi
import pulumi_aws as aws

class StaticSiteArgs:
    def __init__(self,
                 index_document: pulumi.Input[str] = "index.html",
                 error_document: pulumi.Input[str] = "error.html"):
        self.index_document = index_document
        self.error_document = error_document

class StaticSite(pulumi.ComponentResource):
    bucket_name: pulumi.Output[str]
    website_url: pulumi.Output[str]

    def __init__(self, name: str, args: StaticSiteArgs,
                 opts: pulumi.ResourceOptions = None):
        super().__init__("myorg:index:StaticSite", name, None, opts)

        bucket = aws.s3.Bucket(f"{name}-bucket",
            opts=pulumi.ResourceOptions(parent=self))

        website = aws.s3.BucketWebsiteConfigurationV2(f"{name}-website",
            bucket=bucket.id,
            index_document=aws.s3.BucketWebsiteConfigurationV2IndexDocumentArgs(
                suffix=args.index_document,
            ),