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In this video, we are going to start to develop our lambda function.

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But before that it is good to understand how Amazon is treated with the lambda function and what is

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the event JSON for that purpose.

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We can go to a lambda function and if you come here come to test.

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But we can remember that.

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We can see the templates.

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If you copy and open this dropdown and search for the S3, you can see the S3, put example, even JSON

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object in the template of the test file into the mission console.

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Here you can see the example evaluation.

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So that means this comes from the records array and every record has these kind of attributes that we

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can get these object key size and all these information about Amazon S3 bucket name and the object name.

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So this is the example event JSON format that we can develop our lambda function.

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But I would like to get the exactly right event JSON file from our S3 bucket.

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For that purpose.

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I'm going to trigger this S3 upload object from uploading any object into S3 and see the lambda function

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logs that invoke from the asynchronously from the S3.

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Please go to a three page and I'm going to upload an object click to upload and add file, go to section

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folder.

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And if you go to record section folder, you can see the index HTML file.

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I am going to upload the index HTML file.

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So if you click the upload button, this should trigger or a lambda function asynchronously.

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So upload succeeded.

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If you come back to our lambda function and go to monitor and we logs in the cloud watch logs, we should

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see the invocation log.

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Yes, it comes for the invocation logs.

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If you click this incoming event, JSON and copy this JSON.

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And past the hour.

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We used to do a code lecture folder.

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I have created a separate lecture folder and add the stream JSON file.

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If you copy and paste in here and remove the first line and save this file, we can reach the exact

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same and correct incoming event JSON from the S3 to Lambda function.

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Here we have a records array and we only have one record and in the S3 section we can get the bucket

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name principal Aaron and also object.

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It is in here as you can see that we have upload indexed html file and this is the size and the other

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attribute and informations.

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Okay, very good.

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So now we can start developing our lambda function with this incoming S3 limitation file.

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So basically we will get these information about S3 and write down into the Dynamo DB table.

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I'm going to write the bucket name and also object name into Dynamo DB table.

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That means in the lambda function we will have to interaction.

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So we will get the bucket name and detail from the S3 and after that write Dynamo DB table.

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That's why in the permission top we have these permissions into our execution role.

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If you come back to our lambda function and come to configuration and permission, you can see that

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we have both dynamic DB and S3 requirement permissions because we will read the details of the S3 bucket

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from Amazon S3 and write these information into the dynamic DB table.

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Okay.

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How we can interact with these resources.

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Of course, we will use the Amazon SDK JavaScript version three libraries.

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So let's start to developing.