MinIO Has a Free API: S3-Compatible Object Storage You Can Self-Host

#selfhosted #cloud #tutorial #devops

What is MinIO?

MinIO is a high-performance, S3-compatible object storage server. It's the most popular self-hosted alternative to AWS S3 — used by companies like Snowflake, VMware, and Nutanix in production.

100% S3 API compatible. Your existing AWS SDK code works with zero changes.

Quick Start

# Docker
docker run -p 9000:9000 -p 9001:9001 \
  -e MINIO_ROOT_USER=admin \
  -e MINIO_ROOT_PASSWORD=password123 \
  minio/minio server /data --console-address ":9001"

# Or binary
wget https://dl.min.io/server/minio/release/linux-amd64/minio
chmod +x minio
./minio server /data

Console: http://localhost:9001 | API: http://localhost:9000

S3-Compatible API

Use the standard AWS SDK — just point it to your MinIO server:

import { S3Client, PutObjectCommand, GetObjectCommand, ListObjectsV2Command } from "@aws-sdk/client-s3";

const s3 = new S3Client({
  endpoint: "http://localhost:9000",
  region: "us-east-1",
  credentials: {
    accessKeyId: "admin",
    secretAccessKey: "password123",
  },
  forcePathStyle: true,
});

// Upload file
await s3.send(new PutObjectCommand({
  Bucket: "my-bucket",
  Key: "photos/vacation.jpg",
  Body: fileBuffer,
  ContentType: "image/jpeg",
}));

// Download file
const { Body } = await s3.send(new GetObjectCommand({
  Bucket: "my-bucket",
  Key: "photos/vacation.jpg",
}));
const data = await Body.transformToByteArray();

// List objects
const { Contents } = await s3.send(new ListObjectsV2Command({
  Bucket: "my-bucket",
  Prefix: "photos/",
}));
Contents.forEach(obj => console.log(obj.Key, obj.Size));

Python

import boto3

s3 = boto3.client('s3',
    endpoint_url='http://localhost:9000',
    aws_access_key_id='admin',
    aws_secret_access_key='password123'
)

# Upload
s3.upload_file('local.pdf', 'my-bucket', 'documents/file.pdf')

# Download
s3.download_file('my-bucket', 'documents/file.pdf', 'downloaded.pdf')

# List
response = s3.list_objects_v2(Bucket='my-bucket')
for obj in response['Contents']:
    print(obj['Key'], obj['Size'])

MinIO Client (mc)

# Configure
mc alias set myminio http://localhost:9000 admin password123

# Create bucket
mc mb myminio/my-bucket

# Upload
mc cp myfile.txt myminio/my-bucket/
mc cp --recursive ./photos/ myminio/my-bucket/photos/

# Download
mc cp myminio/my-bucket/myfile.txt ./

# List
mc ls myminio/my-bucket/

# Mirror (sync)
mc mirror ./local-dir myminio/my-bucket/backup/

# Set public access
mc anonymous set download myminio/my-bucket/public/

Presigned URLs

import { getSignedUrl } from "@aws-sdk/s3-request-presigner";

// Generate upload URL (valid 1 hour)
const uploadUrl = await getSignedUrl(s3, new PutObjectCommand({
  Bucket: "my-bucket",
  Key: "user-uploads/file.pdf",
}), { expiresIn: 3600 });

// Generate download URL
const downloadUrl = await getSignedUrl(s3, new GetObjectCommand({
  Bucket: "my-bucket",
  Key: "user-uploads/file.pdf",
}), { expiresIn: 3600 });

Event Notifications

# Notify on new objects via webhook
mc event add myminio/my-bucket arn:minio:sqs::1:webhook --event put

# Or via Kafka, NATS, Redis, PostgreSQL, MySQL, Elasticsearch