initial version for the example

Author: gojko

example/Makefile

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+STACK_NAME ?= imagemagick-layer-example
+IMAGE_MAGICK_STACK_NAME ?= imagemagick-layer
+
+IMAGEMAGICK_LAYER ?=(shell aws cloudformation describe-stacks --stack-name $(IMAGE_MAGICK_STACK_NAME) --query Stacks[].Outputs[].OutputValue --output text)
+SOURCES=$(shell find src/)
+
+clean: 
+	rm -rf build
+
+output.yml: template.yml $(SOURCES)
+	mkdir -p build
+	aws cloudformation package --template-file $< --output-template-file $@ --s3-bucket $(DEPLOYMENT_BUCKET_NAME)
+
+deploy: output.yml
+	aws cloudformation deploy --template-file $< --stack-name $(STACK_NAME) --capabilities CAPABILITY_IAM --parameter-overrides ImageMagickLayer=$(IMAGEMAGICK_LAYER)
+	aws cloudformation describe-stacks --stack-name $(STACK_NAME) --query Stacks[].Outputs --output table
+

example/src/child-process-promise.js

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+/*global module, require, console, Promise */
+'use strict';
+const childProcess = require('child_process'),
+	spawnPromise = function (command, argsarray, envOptions) {
+		return new Promise((resolve, reject) => {
+			console.log('executing', command, argsarray.join(' '));
+			const childProc = childProcess.spawn(command, argsarray, envOptions || {env: process.env, cwd: process.cwd()}),
+				resultBuffers = [];
+			childProc.stdout.on('data', buffer => {
+				console.log(buffer.toString());
+				resultBuffers.push(buffer);
+			});
+			childProc.stderr.on('data', buffer => console.error(buffer.toString()));
+			childProc.on('exit', (code, signal) => {
+				console.log(`${command} completed with ${code}:${signal}`);
+				if (code || signal) {
+					reject(`${command} failed with ${code || signal}`);
+				} else {
+					resolve(Buffer.concat(resultBuffers).toString().trim());
+				}
+			});
+		});
+	};
+module.exports = {
+	spawn: spawnPromise
+};

example/src/index.js

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+
+const s3Util = require('./s3-util'),
+	childProcessPromise = require('./child-process-promise'),
+	path = require('path'),
+	os = require('os'),
+	EXTENSION = process.env.EXTENSION,
+	THUMB_WIDTH = process.env.THUMB_WIDTH,
+	OUTPUT_BUCKET = process.env.OUTPUT_BUCKET,
+	MIME_TYPE =  process.env.MIME_TYPE;
+
+exports.handler = function (eventObject, context) {
+	const eventRecord = eventObject.Records && eventObject.Records[0],
+		inputBucket = eventRecord.s3.bucket.name,
+		key = eventRecord.s3.object.key,
+		id = context.awsRequestId,
+		resultKey = key.replace(/\.[^.]+$/, EXTENSION),
+		workdir = os.tmpdir(),
+		inputFile = path.join(workdir,  id + path.extname(key)),
+		outputFile = path.join(workdir, 'converted-' + id + EXTENSION);
+
+
+	console.log('converting', inputBucket, key, 'using', inputFile);
+	return s3Util.downloadFileFromS3(inputBucket, key, inputFile)
+		.then(() => childProcessPromise.spawn(
+			'/opt/bin/convert',
+			[inputFile, '-resize', `${THUMB_WIDTH}x`, outputFile],
+			{env: process.env, cwd: workdir}
+		))
+		.then(() => s3Util.uploadFileToS3(OUTPUT_BUCKET, resultKey, outputFile, MIME_TYPE));
+};

example/src/s3-util.js

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+/*global module, require, Promise, console */
+
+const aws = require('aws-sdk'),
+	fs = require('fs'),
+	s3 = new aws.S3(),
+	downloadFileFromS3 = function (bucket, fileKey, filePath) {
+		'use strict';
+		console.log('downloading', bucket, fileKey, filePath);
+		return new Promise(function (resolve, reject) {
+			const file = fs.createWriteStream(filePath),
+				stream = s3.getObject({
+					Bucket: bucket,
+					Key: fileKey
+				}).createReadStream();
+			stream.on('error', reject);
+			file.on('error', reject);
+			file.on('finish', function () {
+				console.log('downloaded', bucket, fileKey);
+				resolve(filePath);
+			});
+			stream.pipe(file);
+		});
+	}, uploadFileToS3 = function (bucket, fileKey, filePath, contentType) {
+		'use strict';
+		console.log('uploading', bucket, fileKey, filePath);
+		return s3.upload({
+			Bucket: bucket,
+			Key: fileKey,
+			Body: fs.createReadStream(filePath),
+			ACL: 'private',
+			ContentType: contentType
+		}).promise();
+	};
+
+module.exports = {
+	downloadFileFromS3: downloadFileFromS3,
+	uploadFileToS3: uploadFileToS3
+};

example/template.yml

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+AWSTemplateFormatVersion: 2010-09-09
+Transform: AWS::Serverless-2016-10-31
+Description: >
+  Example project demonstrating the usage of the ImageMagic Layer for AWS Linux 2 runtimes.
+
+Parameters:
+  ImageMagickLayer:
+    Type: String
+  ConversionFileType:
+    Type: String
+    Default: png
+  ConversionMimeType:
+    Type: String
+    Default: image/png 
+  ThumbnailWidth:
+    Type: Number
+    Default: 500
+Resources:
+  UploadBucket:
+    Type: AWS::S3::Bucket
+
+  ResultsBucket:
+    Type: AWS::S3::Bucket
+
+  ConvertFileFunction:
+    Type: AWS::Serverless::Function
+    Properties:
+      Handler: index.handler
+      Timeout: 180
+      MemorySize: 1024
+      Runtime: nodejs10.x
+      CodeUri: src
+      Layers:
+        - !Ref ImageMagickLayer
+      Policies:
+      - S3CrudPolicy:
+          BucketName: !Sub "${AWS::StackName}-*"
+      Environment:
+        Variables:
+          OUTPUT_BUCKET: !Ref ResultsBucket
+          EXTENSION: !Sub '.${ConversionFileType}'
+          MIME_TYPE: !Ref ConversionMimeType
+          THUMB_WIDTH: !Ref ThumbnailWidth
+      Events:
+        FileUpload:
+          Type: S3
+          Properties:
+            Bucket: !Ref UploadBucket
+            Events: s3:ObjectCreated:*
+
+Outputs:
+    UploadBucket:
+      Description: "Upload S3 bucket"
+      Value: !Ref UploadBucket
+    ResultsBucket:
+      Description: "Results S3 bucket"
+      Value: !Ref ResultsBucket
+