minio/docs/gateway/s3.md

# MinIO S3 Gateway [![Slack](https://slack.min.io/slack?type=svg)](https://slack.min.io)

MinIO S3 Gateway adds MinIO features like MinIO Browser and disk caching to AWS S3 or any other AWS S3 compatible service.

## Run MinIO Gateway for AWS S3
As a prerequisite to run MinIO S3 gateway, you need valid AWS S3 access key and secret key by default. Optionally you can also set custom access/secret key, when you have rotating AWS IAM credentials or AWS credentials through environment variables (i.e. AWS_ACCESS_KEY_ID)

### Using Docker
```
docker run -p 9000:9000 --name minio-s3 \
 -e "MINIO_ACCESS_KEY=aws_s3_access_key" \
 -e "MINIO_SECRET_KEY=aws_s3_secret_key" \
 minio/minio gateway s3
```

### Using Binary
```
export MINIO_ACCESS_KEY=aws_s3_access_key
export MINIO_SECRET_KEY=aws_s3_secret_key
minio gateway s3
```

### Using Binary in EC2
Using IAM rotating credentials for AWS S3
```
export MINIO_ACCESS_KEY=custom_access_key
export MINIO_SECRET_KEY=custom_secret_key
minio gateway s3
```

MinIO gateway will automatically look for list of credential styles in following order, if your backend URL is AWS S3.

- AWS env vars (i.e. AWS_ACCESS_KEY_ID)
- AWS creds file (i.e. AWS_SHARED_CREDENTIALS_FILE or ~/.aws/credentials)
- IAM profile based credentials. (performs an HTTP call to a pre-defined endpoint, only valid inside configured ec2 instances)

Minimum permissions required if you wish to provide restricted access with your AWS credentials, please make sure you have following IAM policies attached for your AWS user or roles.

```json
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "readonly",
            "Effect": "Allow",
            "Action": [
                "s3:GetObject",
                "s3:ListBucket"
            ],
            "Resource": "arn:aws:s3:::testbucket"
        },
        {
            "Sid": "readonly",
            "Effect": "Allow",
            "Action": "s3:HeadBucket",
            "Resource": "arn:aws:s3:::testbucket"
        }
    ]
}
```

## Run MinIO Gateway for AWS S3 compatible services
As a prerequisite to run MinIO S3 gateway on an AWS S3 compatible service, you need valid access key, secret key and service endpoint.

### Using Docker
```
docker run -p 9000:9000 --name minio-s3 \
 -e "MINIO_ACCESS_KEY=access_key" \
 -e "MINIO_SECRET_KEY=secret_key" \
 minio/minio gateway s3 https://s3_compatible_service_endpoint:port
```

### Using Binary
```
export MINIO_ACCESS_KEY=access_key
export MINIO_SECRET_KEY=secret_key
minio gateway s3 https://s3_compatible_service_endpoint:port
```

## MinIO Caching
MinIO edge caching allows storing content closer to the applications. Frequently accessed objects are stored in a local disk based cache. Edge caching with MinIO gateway feature allows

- Dramatic improvements for time to first byte for any object.
- Avoid S3 [data transfer charges](https://aws.amazon.com/s3/pricing/).

Refer [this document](https://docs.min.io/docs/minio-disk-cache-guide.html) to get started with MinIO Caching.

## MinIO Browser
MinIO Gateway comes with an embedded web based object browser. Point your web browser to http://127.0.0.1:9000 to ensure that your server has started successfully.

![Screenshot](https://github.com/minio/minio/blob/master/docs/screenshots/minio-browser-gateway.png?raw=true)

With MinIO S3 gateway, you can use MinIO browser to explore AWS S3 based objects.

### Known limitations

- Bucket notification APIs are not supported.

## Explore Further

- [`mc` command-line interface](https://docs.min.io/docs/minio-client-quickstart-guide)
- [`aws` command-line interface](https://docs.min.io/docs/aws-cli-with-minio)
- [`minio-go` Go SDK](https://docs.min.io/docs/golang-client-quickstart-guide)