Data Backends

Plik supports multiple storage backends for uploaded files.

File (Default)

Stores files in a local or mounted filesystem directory.

DataBackend = "file"
[DataBackendConfig]
    Directory = "files"

Amazon S3

Compatible with any S3-compatible storage (AWS, MinIO, etc.).

DataBackend = "s3"
[DataBackendConfig]
    Endpoint = "s3.amazonaws.com"
    AccessKeyID = "your-access-key"
    SecretAccessKey = "your-secret-key"
    Bucket = "plik"
    Location = "us-east-1"
    Prefix = ""
    UseSSL = true
    BucketLookup = "auto"  # Bucket addressing style: "auto" (default), "dns" (virtual-hosted), "path" (required for Cloudflare R2 and some MinIO deployments)
    PartSize = 16777216  # 16MiB chunks (min 5MiB, max file = PartSize × 10000)
    PartUploadConcurrency = 4  # Parallel part upload threads (default 4, 1 = sequential)
    SendContentMd5 = false  # Use Content-MD5 instead of x-amz-checksum-* headers (for strict S3-compatible APIs like B2)

Provider-Specific Configuration

Cloudflare R2

R2 requires path-style bucket addressing (BucketLookup = "path") because its TLS wildcard certificate does not cover virtual-hosted-style subdomains.
Set Location to "auto" or the value defined for your bucket in the R2 Console:

BucketLookup = "path"
Location = "auto"

Backblaze B2

B2's S3-compatible API does not support the newer x-amz-checksum-* headers. Enable legacy Content-MD5 checksums:

SendContentMd5 = true

Upload Strategy

Plik uses a buffer-then-decide strategy for S3 uploads:

• Small files (≤ PartSize): uploaded via a single PUT request with the exact size — optimal latency, minimal overhead.
• Large files (> PartSize): uploaded via S3 multipart upload with PartUploadConcurrency parallel part uploads (default: 4). Set to 1 for sequential uploads. Memory usage per upload: PartUploadConcurrency × PartSize.

Bucket Versioning

WARNING

Plik permanently deletes files from the S3 bucket, even if bucket versioning is enabled. Consider disabling versioning on your Plik bucket to avoid accumulating unnecessary delete markers.

Server-Side Encryption

Mode	Description
SSE-C	Encryption keys managed by Plik
S3	Encryption keys managed by the S3 backend

[DataBackendConfig]
    SSE = "SSE-C"  # or "S3"

OpenStack Swift

DataBackend = "swift"
[DataBackendConfig]
    Container = "plik"
    AuthUrl = "https://auth.swiftapi.example.com/v2.0/"
    UserName = "user@example.com"
    ApiKey = "xxxxxxxxxxxxxxxx"
    Domain = "domain"   # v3 auth only
    Tenant = "tenant"   # v2 auth only

See the ncw/swift documentation for all available connection settings (v1/v2/v3).

Google Cloud Storage

DataBackend = "gcs"
[DataBackendConfig]
    Bucket = "my-plik-bucket"
    Folder = "plik"

Requires Application Default Credentials or a service account key.