Struct StorageConfig 

pub struct StorageConfig {

    pub backend: String,
    pub dir: String,
    pub public_base: String,
    pub max_size_mb: u64,
    pub allowed_types: Vec<String>,
    pub bucket: String,
    pub region: String,
    pub endpoint: String,
    pub access_key_id: String,
    pub secret_access_key: String,
    pub path_style: Option<bool>,
    pub prefix: String,
    pub base_url: String,
}

Where uploaded files go.

A file field holds a relative URL — /files/2026/…/logo.png — never a bucket address, and the server answers that URL from whichever backend is configured. That is the whole point of the indirection: an app that starts on a mounted volume and later moves to S3 changes four lines of TOML and nothing else. No row is rewritten, because no row ever named the backend.

# A directory — a Docker volume, in practice.
[storage]
backend = "local"
dir     = "storage"

# Or block storage. `r2` is `s3` with an endpoint, and so is MinIO.
[storage]
backend           = "s3"
bucket            = "app-uploads"
region            = "auto"
endpoint          = "https://${R2_ACCOUNT}.r2.cloudflarestorage.com"
access_key_id     = "${R2_ACCESS_KEY_ID}"
secret_access_key = "${R2_SECRET_ACCESS_KEY}"

Fields

backend: String

local (the default), s3, or none to refuse uploads outright.

dir: String

local: the directory uploads are written to, relative to the app root unless absolute. In a container this is what you mount a volume at.

public_base: String

URL prefix the stored links carry and the server answers on. Always starts with / and never ends with one (normalised on load).

max_size_mb: u64

Largest upload accepted, in megabytes.

allowed_types: Vec<String>

Content types an upload may declare, as exact types (image/png) or wildcards (image/*). Empty (the default) accepts anything — an authenticated caller is already trusted to write a row.

bucket: String

s3: the bucket. Required when backend = "s3".

region: String

s3: the region. R2 and most S3-compatibles want auto.

endpoint: String

s3: the API origin. Empty uses AWS’s own (https://<bucket>.s3.<region>.amazonaws.com); set it for R2, MinIO, Backblaze or any other S3-compatible service.

access_key_id: String

s3: credentials.

secret_access_key: String

path_style: Option<bool>

s3: address objects as <endpoint>/<bucket>/<key> rather than putting the bucket in the hostname. Required by MinIO and by R2 (the default when an endpoint is set).

prefix: String

Key prefix inside the bucket or directory, so several apps can share one.

base_url: String

Serve files from somewhere else entirely — a CDN, or a public bucket — by storing absolute URLs under this origin instead of relative ones.

Empty (the default) keeps links relative and proxies reads through the server, which is what makes a private bucket work. Setting it is a deliberate trade: faster, but the objects must be publicly readable and the links stop being portable.

Implementations

impl StorageConfig

pub fn is_active(&self) -> bool

Whether uploads are accepted at all.

pub fn normalized_public_base(&self) -> String

/files — leading slash, no trailing slash, whatever was written.

pub fn uses_path_style(&self) -> bool

Whether objects are addressed as <endpoint>/<bucket>/<key>. Explicit when written down; otherwise path-style exactly when a custom endpoint is set, since that is what every S3-compatible service but AWS wants.

pub fn max_size_bytes(&self) -> u64

Trait Implementations

impl Clone for StorageConfig

fn clone(&self) -> StorageConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StorageConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for StorageConfig

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for StorageConfig

where StorageConfig: Default,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.