Write a file to S3

Serverless Framework
1

Hi everyone,

I am new to serverless and AWS Lambda. I want to write a .js file in my S3 bucket. What permission should I define in serverless.yml and how?

Now my code looks like this;
iamRoleStatements:
- Effect: “Allow”
Resource: S3Bucket*
Action:
- “s3:ListBucket”
- “s3:PutObject”

But it does not work.

Thanks.

2

Maybe start with “s3:*” to make sure your code works…?

Also post your complete serverless.yml so it is easier to pinpoint where it goes wrong.

3

Hi there,

Thanks for your answer. Here are my full serverless.yml

serverless.yml

service: my-express-application

provider:
name: aws
iamRoleStatements:
- Effect: “Allow”
Action:
- “s3:PutObject”
- “s3:DeleteObject”
- “s3:DeleteObjects”
- “s3:GetObject”
Resource: arn:aws:s3::AAAAAAAA
runtime: nodejs8.10
stage: dev
region: us-east-1
profile: serverless-admin

functions:
app:
handler: index.handler
events:
- http: ANY /
- http: ‘ANY {proxy+}’

My function is;

const serverless = require(‘serverless-http’);
const express = require(‘express’)
const app = express()

const AWS = require(‘aws-sdk’);
const s3 = new AWS.S3();

app.get(’/’, function (req, res) {

var params = {
Bucket: ‘AAAA’
};
s3.getBucketPolicyStatus(params, function(err, data) {
if (err) console.log(err, err.stack); // an error occurred
else console.log(data); // successful response
});
})

module.exports.handler = serverless(app);

But it does not work.

4

Hi, if you call s3.getBucketPolicy - you need to have the s3:GetBucketPolicyStatus permission. https://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketGETPolicyStatus.html
As for logs, what error did you get?