今天正好遇到了这个问题，就在官方文档里查询，然后根据他的说明整理了一下大致的流程，详细的请参考AWS国际版的官方文档，这里只是作者的一个简单的流程展示。
Lambda和S3连接
1.在S3的同一区域当中创建2个桶
命名规则：source
Sourceresized
2.往source的S3桶中上传一张命名为HappyFace.jpg的文件
3.准备一台安装好node.js的服务器
①创建一个文件夹
mkdir examplefolder
②在这个文件夹路径下创建一个子文件夹
cd examplefolder
mkdir node_modules
③安装插件，在当前路径下
npm install async gm
④安装完毕，创建一个文件index.js
touch index.js
⑤打开index.js文本进行编辑，编辑内容如下
vi index.js
按“i”进行编辑
// dependencies
var async = require('async');
var AWS = require('aws-sdk');
var gm = require('gm')
.subClass({ imageMagick: true }); // Enable ImageMagick integration.
var util = require('util');
// constants
var MAX_WIDTH = 100;
var MAX_HEIGHT = 100;
// get reference to S3 client
var s3 = new AWS.S3();
exports.handler = function(event, context, callback) {
// Read options from the event.
console.log("Reading options from event: ", util.inspect(event, {depth: 5}));
var srcBucket = event.Records[0].s3.bucket.name;
// Object key may have spaces or unicode non-ASCII characters.
var srcKey =
decodeURIComponent(event.Records[0].s3.object.key.replace(/+/g, " "));
var dstBucket = srcBucket + "resized";
var dstKey = "resized-" + srcKey;
// Sanity check: validate that source and destination are different buckets.
if (srcBucket == dstBucket) {
callback("Source and destination buckets are the same.");
return;
}
// Infer the image type.
var typeMatch = srcKey.match(/.([^.]*)$/);
if (!typeMatch) {
callback("Could not determine the image type.");
return;
}
var imageType = typeMatch[1];
if (imageType != "jpg" && imageType != "png") {
callback('Unsupported image type: ${imageType}');
return;
}
// Download the image from S3, transform, and upload to a different S3 bucket.
async.waterfall([
function download(next) {
// Download the image from S3 into a buffer.
s3.getObject({
Bucket: srcBucket,
Key: srcKey
},
next);
},
function transform(response, next) {
gm(response.Body).size(function(err, size) {
// Infer the scaling factor to avoid stretching the image unnaturally.
var scalingFactor = Math.min(
MAX_WIDTH / size.width,
MAX_HEIGHT / size.height
);
var width = scalingFactor * size.width;
var height = scalingFactor * size.height;
// Transform the image buffer in memory.
this.resize(width, height)
.toBuffer(imageType, function(err, buffer) {
if (err) {
next(err);
} else {
next(null, response.ContentType, buffer);
}
});
});
},
function upload(contentType, data, next) {
// Stream the transformed image to a different S3 bucket.
s3.putObject({
Bucket: dstBucket,
Key: dstKey,
Body: data,
ContentType: contentType
},
next);
}
], function (err) {
if (err) {
console.error(
'Unable to resize ' + srcBucket + '/' + srcKey +
' and upload to ' + dstBucket + '/' + dstKey +
' due to an error: ' + err
);
} else {
console.log(
'Successfully resized ' + srcBucket + '/' + srcKey +
' and uploaded to ' + dstBucket + '/' + dstKey
);
}
callback(null, "message");
}
);
};
编辑完毕按“Esc”退出，然后按“：wq”→enter保存退出
⑥当前路径下应有如下内容
index.js
/node_modules/gm
/node_modules/async
对如下内容进行打包
命令：
tar -czvf ./* ./CreateThumbnail.zip
然后把包导出来
⑦创建IAM角色
⑧在lambda上上传压缩包
⑨在lambda上进行S3的调用测试
代码如下
{
"Records":[
{
"eventVersion":"2.0",
"eventSource":"aws:s3",
"awsRegion":"us-west-2",
"eventTime":"1970-01-01T00:00:00.000Z",
"eventName":"ObjectCreated:Put",
"userIdentity":{
"principalId":"AIDAJDPLRKLG7UEXAMPLE"
},
"requestParameters":{
"sourceIPAddress":"127.0.0.1"
},
"responseElements":{
"x-amz-request-id":"C3D13FE58DE4C810",
"x-amz-id-2":"FMyUVURIY8/IgAtTv8xRjskZQpcIZ9KG4V5Wp6S7S/JRWeUWerMUE5JgHvANOjpD"
},
"s3":{
"s3SchemaVersion":"1.0",
"configurationId":"testConfigRule",
"bucket":{
"name":"sourcebucket",
"ownerIdentity":{
"principalId":"A3NL1KOZZKExample"
},
"arn":"arn:aws:s3:::sourcebucket"
},
"object":{
"key":"HappyFace.jpg", #S3source 桶里面放的文件名
"size":1024,
"eTag":"d41d8cd98f00b204e9800998ecf8427e",
"versionId":"096fKKXTRTtl3on89fVO.nfljtsv6qko"
}
}
}
]
}
⑩在S3那个sourceresized的S3桶里查看是否有文件生成
生成为成功，没有内容再调查问题原因。