add resize impl

Author: samuraikun

README.md

@@ -0,0 +1,95 @@
+# image-resizer-lambda-serverless
+AWS Lambda to resize image when upload image to specific S3 bucket.
+
+## Runtime
+- Ruby2.7
+
+## Deploy & Resource Setting
+- Serverless Framework
+
+## Setup
+
+#### required
+- Docker
+- AWS Account & AWS CLI
+
+### Add AWS credential
+
+```bash
+$ touch docker.env
+```
+
+`docker.env`
+
+```bash
+AWS_ACCESS_KEY_ID=xxx
+AWS_DEFAULT_REGION=ap-northeast-1
+AWS_SECRET_ACCESS_KEY=xxx
+```
+
+### docker-compose
+
+```bash
+$ docker-compose build
+$ docker-compose --rm run serverless sh
+
+sh-4.2# bundle config set path 'vendor/bundle'
+sh-4.2# bundle install
+```
+
+## Debug Lambda
+
+### use `bundle exec ruby` in docker-compose
+For example, you insert `binding.irb` in `handler.rb` for debug.
+
+You command below
+
+```bash
+sh-4.2# bundle exec ruby handler.rb
+```
+
+### docker-lambda
+- WIP
+
+## Deploy
+
+```bash
+sh-4.2# sls deploy
+
+# Remove Resources
+sh-4.2# sls remove
+```
+
+## Lambda Layer
+deploy [`libvips`](https://github.com/libvips/libvips) to lambda layer for native extendions.
+
+use https://github.com/customink/ruby-vips-lambda
+
+```
+$ git clone https://github.com/customink/ruby-vips-lambda.git
+$ cd ruby-vips-lambda
+$ ./bin/deploy
+```
+
+#### If you deploy to layer other region(not us-east-1)
+- change `AWS_DEFAULT_REGION` in `ruby-vips-lambda/bin/deploy`
+
+```
+#!/bin/bash
+
+set -e
+
+./bin/build
+
+export VIPS_VERSION=$(cat share/VIPS_VERSION)
+export LAYER_NAME="rubyvips${VIPS_VERSION//./}-27"
+
+# change here
+export AWS_REGION=${AWS_REGION:=ap-northeast-1}
+
+aws lambda publish-layer-version \
+  --region $AWS_REGION \
+  --layer-name $LAYER_NAME \
+  --description "Libvips for Ruby FFI." \
+  --zip-file "fileb://share/libvips.zip"
+```

handler.rb

@@ -1,11 +1,8 @@
-require 'json'
+require_relative "./lib/image_service"
 
 def handler(event:, context:)
-  {
-    statusCode: 200,
-    body: {
-      message: 'Go Serverless v1.0! Your function executed successfully!',
-      input: event
-    }.to_json
-  }
+  key     = event["Records"][0].dig("s3", "object", "key")
+  resizer = ImageService::Resizer.new(key, 280)
+
+  resizer.resize!
 end

lib/image_service.rb

@@ -0,0 +1,7 @@
+require_relative "./image_service/resizer"
+
+module ImageService
+  def self.❨╯°□°❩╯︵┻━┻
+    puts "Calm down, yo."
+  end
+end

lib/image_service/resizer.rb

@@ -0,0 +1,67 @@
+require "aws-sdk-s3"
+require "image_processing/vips"
+
+module ImageService
+  class Resizer
+    CLIENT = Aws::S3::Client.new(region: "ap-northeast-1")
+    BUCKET = "yuichi-kojima-test2"
+
+    attr_reader :key, :size
+
+    def initialize(key, width = 280, height = nil)
+      @key = key
+      @width = width
+      @height = height
+    end
+
+    def resize!
+      return if resized?
+
+      resized = ImageProcessing::Vips
+        .source(source)
+        .resize_to_limit(@width, @height)
+        .call(save: false)
+        .write_to_buffer(File.extname(@key))
+
+      put_object resized, new_key
+    end
+
+    def source
+      if File.extname(@key) == ".png"
+        Vips::Image.pngload_buffer(get_object)
+      elsif File.extname(@key) == ".gif"
+        Vips::Image.thumbnail(@key, @width)
+      else
+        Vips::Image.new_from_buffer(get_object, File.extname(@key))
+      end
+    end
+
+    def new_key
+      "resized/#{File.basename(@key, File.extname(@key))}-#{@width}#{File.extname(@key)}"
+    end
+
+    def get_object
+      CLIENT.get_object(bucket: BUCKET, key: @key).body.read
+    end
+
+    def put_object(object, put_key)
+      CLIENT.put_object(
+        bucket: BUCKET,
+        key: put_key,
+        body: object,
+        metadata: { resized: "1" }
+      )
+    end
+
+    def resized?
+      metadata[:resized]
+    end
+
+    def metadata
+      response = CLIENT.head_object(bucket: BUCKET, key: @key)
+      response.metadata || {}
+    rescue Aws::S3::Errors::NotFound
+      {}
+    end
+  end
+end