File Transfer Protocol (FTP/SFTP)

File Transport Using FTP and SFTP with MinIO

New in version Operator: v5.0.7

Overview

Starting with Operator 5.0.7 and MinIO Server RELEASE.2023-04-20T17-56-55Z, you can use the SSH File Transfer Protocol (SFTP) to interact with the objects on a MinIO Operator Tenant deployment.

SFTP is defined by the Internet Engineering Task Force (IETF) as an extension of SSH 2.0. It allows file transfer over SSH for use with Transport Layer Security (TLS) and virtual private network (VPN) applications.

Enabling SFTP does not affect other MinIO features.

Supported Commands

When enabled, MinIO supports the following SFTP operations:

get
put
ls
mkdir
rmdir
delete

MinIO does not support either append or rename operations.

MinIO Operator only supports the SFTP file transfer protocol. Other protocols, such as FTP, are not supported for accessing Tenants.

Considerations

Versioning

SFTP clients can only operate on the latest version of an object. Specifically:

For read operations, MinIO only returns the latest version of the requested object(s) to the SFTP client.
For write operations, MinIO applies normal versioning behavior and creates a new object version at the specified namespace. rm and rmdir operations create DeleteMarker objects.

Authentication and Access

SFTP access requires the same authentication as any other S3 client. MinIO supports the following authentication providers:

MinIO IDP users and their service accounts
Active Directory/LDAP users and their service accounts
OpenID/OIDC service accounts

STS credentials cannot access buckets or objects over SFTP.

Authenticated users can access buckets and objects based on the policies assigned to the user or parent user account.

The SFTP protocol does not require any of the admin:* permissions. You may not perform other MinIO admin actions with SFTP.

Prerequisites

MinIO Operator v5.0.7 or later.
Enable an SFTP port (8022) for the server.
A port to use for the SFTP commands and a range of ports to allow the SFTP server to request to use for the data transfer.

Procedure

Enable SFTP for the desired Tenant:
Operator Console
- In the Operator Console, click on the Tenant for which to enable SFTP.
- In the Configuration tab, toggle SFTP to Enabled.
- Click Save.
- Click Restart to restart MinIO and apply your changes.
Kubectl
Use the following Kubectl command to edit the Tenant YAML configuration:
kubectl edit tenants/my-tenant -n my-tenant-ns
Replace my-tenant and my-tenant-ns with the desired Tenant and namespace.

In the features: section, set the value of enableSFTP to true:
spec: configuration: name: my-tenant-env-configuration credsSecret: name: my-tenant-secret exposeServices: console: true minio: true features: enableSFTP: true
Kubectl restarts MinIO to apply the change.

You may also set enableSFTP in your Helm chart or Kustomize configuration to enable SFTP for newly created Tenants.
If needed, configure ingress for the SFTP port according to your local policies.
Use your preferred SFTP client to connect to the MinIO deployment. You must connect as a user whose policies allow access to the desired buckets and objects.

The specifics of connecting to the MinIO deployment depend on your SFTP client. Refer to the documentation for your client.

Examples

The following examples use the SFTP CLI client on a Linux system.

Connect to MinIO Using SFTP

The following example connects to an SFTP server, lists the contents of a bucket named test-bucket, and downloads an object.

sftp -P 8022 my-access-key@localhost
my-access-key@localhost's password:
Connected to localhost.
sftp> ls
test-bucket
sftp> ls test-bucket
test-bucket/test-file.txt
sftp> get test-bucket/test-file.txt
Fetching /test-bucket/test-file.txt to test-file.txt
test-file.txt                    100%    6     1.3KB/s   00:00

Check if SFTP is Enabled for a Tenant

The following kubectl get command uses yq to display the value of enableSFTP, indicating whether SFTP is enabled:

kubectl get tenants/my-tenant -n my-tenant-ns -o yaml | yq '.spec.features'

Replace my-tenant and my-tenant-ns with the desired Tenant and namespace.

If SFTP is enabled, the output resembles the following:

enableSFTP: true