Storage Providers

Slink stores images on the local filesystem by default. Set the STORAGE_PROVIDER environment variable to local, smb, or s3 to choose a backend.

Provider	Best for	Key variables
Local (local)	Single-host deployments (default)	None
SMB / CIFS (smb)	Shared network or NAS storage	SMB_HOST, SMB_SHARE, SMB_USERNAME, SMB_PASSWORD
Amazon S3 (s3)	Cloud / scalable object storage	AMAZON_S3_REGION, AMAZON_S3_BUCKET, AMAZON_S3_ACCESS_KEY_ID, AMAZON_S3_SECRET_ACCESS_KEY

Local Storage

The default provider. Stores images on the container’s local filesystem and needs no configuration beyond STORAGE_PROVIDER=local.

Variable	Required	Description
STORAGE_PROVIDER	Yes	Set to local (default).

Caution

To persist images when using Docker, mount the /app/slink/images directory to the host filesystem.

SMB (Samba)

Stores images on a network share over the SMB/CIFS protocol. Useful for centralized storage in enterprise environments.

Variable	Required	Description
STORAGE_PROVIDER	Yes	Set to smb.
SMB_HOST	Yes	Hostname or IP address of the SMB server.
SMB_SHARE	Yes	Name of the SMB share to use.
SMB_USERNAME	Yes	Username for authentication.
SMB_PASSWORD	Yes	Password for authentication.
SMB_WORKGROUP	No	SMB workgroup (defaults to workgroup).

environment:
  STORAGE_PROVIDER: smb
  SMB_HOST: 192.168.1.100
  SMB_SHARE: slink-storage
  SMB_USERNAME: slink-user
  SMB_PASSWORD: your-secure-password
  SMB_WORKGROUP: workgroup

Note

The SMB provider automatically creates the required directory structure (slink/images and slink/cache) on the remote share.

Amazon S3 & Compatible

Stores images in an Amazon S3 bucket (or any S3-compatible service). Ideal for cloud deployments and scalable object storage.

Variable	Required	Description
STORAGE_PROVIDER	Yes	Set to s3.
AMAZON_S3_BUCKET	Yes	Name of your S3 bucket.
AMAZON_S3_REGION	Amazon S3 only	AWS region of your bucket (e.g. us-east-1). Optional for custom S3-compatible providers, where it defaults to auto.
AMAZON_S3_ACCESS_KEY_ID	Unless IAM role	AWS access key ID. Not needed when AMAZON_S3_USE_IAM_ROLE is true.
AMAZON_S3_SECRET_ACCESS_KEY	Unless IAM role	AWS secret access key. Not needed when AMAZON_S3_USE_IAM_ROLE is true.
AMAZON_S3_USE_IAM_ROLE	No	Authenticate with the instance’s IAM role / instance profile instead of static keys. Amazon S3 only; ignored when a custom endpoint or provider is used. Default false.
AMAZON_S3_ENDPOINT	No	Custom endpoint URL for S3-compatible services (e.g. http://localhost:9000). Setting this enables custom-provider mode.
AMAZON_S3_USE_CUSTOM_PROVIDER	No	Enable for S3-compatible services. Default false (auto-enabled when an endpoint is set).
AMAZON_S3_FORCE_PATH_STYLE	No	Force path-style URLs for S3-compatible services. Default false.

environment:
  STORAGE_PROVIDER: s3
  AMAZON_S3_REGION: us-east-1
  AMAZON_S3_BUCKET: my-slink-bucket
  AMAZON_S3_ACCESS_KEY_ID: EXAMPLEKEYID
  AMAZON_S3_SECRET_ACCESS_KEY: exampleSecretKey

When running on AWS with an attached IAM role (e.g. EC2 or ECS), omit the keys and enable the role instead:

environment:
  STORAGE_PROVIDER: s3
  AMAZON_S3_REGION: us-east-1
  AMAZON_S3_BUCKET: my-slink-bucket
  AMAZON_S3_USE_IAM_ROLE: true

For an S3-compatible service:

environment:
  STORAGE_PROVIDER: s3
  AMAZON_S3_REGION: us-east-1
  AMAZON_S3_BUCKET: my-slink-bucket
  AMAZON_S3_ACCESS_KEY_ID: your-access-key
  AMAZON_S3_SECRET_ACCESS_KEY: your-secret-key
  AMAZON_S3_ENDPOINT: http://your-s3-host:9000
  AMAZON_S3_USE_CUSTOM_PROVIDER: true
  AMAZON_S3_FORCE_PATH_STYLE: true

Tip

For better security on AWS, set AMAZON_S3_USE_IAM_ROLE=true to authenticate with the instance’s IAM role instead of static access keys.

Note

The S3 provider stores original images in the bucket root ({filename}) and transformed images under cache/{filename}.

Directory Structure

The local and SMB providers store files using the same layout:

• slink/images/: original uploaded images
• slink/cache/: transformed/cached images