webflux-localstack

Example using Spring webflux on localstack s3 service and localstack testcontainer.

Prerequisites:

• Java 21
• Apache Maven
• Docker
• Python
• Localstack
• awscli-local

Install Localstack and awslocal-cli:

pip install localstack   #pip command depends on Python version, can be pip3 
pip install awscli-local

Setting up local region and credentials to run LocalStack aws requires the region and the credentials to be set in order to run the aws commands. Create the default configuration & the credentials. Below key will ask for the Access key id, secret Access Key, region & output format.

Configure AWS Credentials and region

aws configure --profile default

Config & credential file will be created under ~/.aws folder

NOTE: Please use test as Access key id and secret Access Key to make S3 presign url work. We have added presign url signature verification algorithm to validate the presign url and its expiration. You can configure credentials into the system environment using export command in the linux/Mac system. You also can add credentials in

~/.aws/credentials 

file directly.

export AWS_ACCESS_KEY_ID=test
export AWS_SECRET_ACCESS_KEY=test

Start Localstack with S3 service

SERVICES=s3 DEFAULT_REGION=eu-central-1 DATA_DIR=~/localstack_data_dir localstack start

Create Bucket

awslocal s3 mb s3://sabo-s3-bucket

Edit application configuration to edit localstack properties

src/main/reources/application.yml

config:
  aws:
    region: eu-central-1
    s3:
      url: http://127.0.0.1:4566    #Default Localstack URL
      bucket-name: sabo-s3-bucket   #Name of the bucket you created previously
      access-key: test
      secret-key: test

Build & run the application

./mvnw package
java -jar ./target/weflux-localstack-2.1.0.jar

Upload file eg (using HTTPie)

http :8080/api/s3                                 # List objects in bucket
http -f post :8080/api/s3/upload files@~/aaa.txt  # Upload a file to bucket
http :8080/api/s3/download/aaa.txt                # Download a file from bucket