Sharp in Lambda

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Uses the Sharp library to resize images. In this example, it resizes a logo.png local file to 100x100 pixels.

sst.config.ts

{
  nodejs: { install: ["sharp"] }
}

We don’t need a layer to deploy this because sharp comes with a pre-built binary for Lambda. This is handled by nodejs.install.

Tip

You don’t need to use a Lambda layer to use Sharp.

In dev, this uses the sharp npm package locally.

package.json

{
  "dependencies": {
    "sharp": "^0.33.5"
  }
}

On deploy, SST will use the right binary from the sharp package for the target Lambda architecture.

sst.config.ts

const func = new sst.aws.Function("MyFunction", {
  url: true,
  handler: "index.handler",
  nodejs: { install: ["sharp"] },
  copyFiles: [{ from: "logo.png" }],
});

index.ts

import sharp from "sharp";
import { promises as fs } from "fs";

export async function handler() {
  const imagePath = "logo.png";

  try {
    // Read the image file
    const imageBuffer = await fs.readFile(imagePath);

    // Resize the image
    const resizedImage = await sharp(imageBuffer)
      .resize(100, 100) // Resize to 100x100
      .toBuffer();

    // Convert the buffer to base64
    const body = resizedImage.toString("base64");

    console.log("Successfully resized logo.png");

    return {
      body,
      statusCode: 200,
      headers: {
        "Content-Type": "image/png",
        "Content-Disposition": "inline"
      },
      isBase64Encoded: true
    };
  } catch (error) {
    console.log(error);
    return {
      statusCode: 500,
      body: JSON.stringify("Error resizing image: " + error.message),
    };
  }
}

View the full example.