Add support for S3-backed image storage

README.md

@@ -50,7 +50,7 @@ or `PODMAN` to use another container command, for example `make PODMAN=docker`.
 5. Install `sqlx-cli`: `cargo install sqlx-cli`.
 6. Run migrations: `sqlx migrate run`.
 7. Set environment variables:
-    * `DATABASE_URL` - the URL of your MySQL database (`mysql://user[:password]@domain/database`)
+    - `DATABASE_URL` - the URL of your MySQL database (`mysql://user[:password]@domain/database`)
 8. Build: `cargo build --release`
 
 ### Configuring
@@ -58,32 +58,76 @@ or `PODMAN` to use another container command, for example `make PODMAN=docker`.
 Reminder Bot reads a number of environment variables. Some are essential, and others have hardcoded
 fallbacks. Environment variables can be loaded from a .env file in the working directory.
 
-__Required Variables__
+**Required Variables**
 
-* `DATABASE_URL` - the URL of your MySQL database (`mysql://user[:password]@domain/database`)
-* `DISCORD_TOKEN` - your application's bot user's authorization token
+-   `DATABASE_URL` - the URL of your MySQL database (`mysql://user[:password]@domain/database`)
+-   `DISCORD_TOKEN` - your application's bot user's authorization token
 
-__Other Variables__
+**Other Variables**
 
-* `MIN_INTERVAL` - default `600`, defines the shortest interval the bot should accept
-* `LOCAL_TIMEZONE` - default `UTC`, necessary for calculations in the natural language processor
-* `SUBSCRIPTION_ROLES` - default `None`, accepts a list of Discord role IDs that are given to
-  subscribed users
-* `CNC_GUILD` - default `None`, accepts a single Discord guild ID for the server that the
-  subscription roles belong to
-* `PYTHON_LOCATION` - default `/usr/bin/python3`. Can be changed if your Python executable is
-  located somewhere else
-* `THEME_COLOR` - default `8fb677`. Specifies the hex value of the color to use on info message
-  embeds
+-   `MIN_INTERVAL` - default `600`, defines the shortest interval the bot should accept
+-   `LOCAL_TIMEZONE` - default `UTC`, necessary for calculations in the natural language processor
+-   `SUBSCRIPTION_ROLES` - default `None`, accepts a list of Discord role IDs that are given to
+    subscribed users
+-   `CNC_GUILD` - default `None`, accepts a single Discord guild ID for the server that the
+    subscription roles belong to
+-   `PYTHON_LOCATION` - default `/usr/bin/python3`. Can be changed if your Python executable is
+    located somewhere else
+-   `THEME_COLOR` - default `8fb677`. Specifies the hex value of the color to use on info message
+    embeds
+
+### Dashboard image uploads
+
+Image URL inputs offer an **Upload image** button when all of these settings are supplied:
+
+-   `S3_BUCKET` — destination bucket name.
+-   `S3_REGION` — bucket region, for example `eu-west-2`.
+-   `S3_ACCESS_KEY_ID` and `S3_SECRET_ACCESS_KEY` — credentials with `s3:PutObject` and
+    `s3:DeleteObject` permissions for the bucket's `uploads/` prefix.
+-   `S3_PUBLIC_URL` — public base URL for the bucket or CDN, for example
+    `https://my-bucket.s3.eu-west-2.amazonaws.com`. Objects must be publicly readable through
+    this URL; the application does not change bucket policies or set object ACLs.
+
+`NSFW_CHECK_ENABLED` defaults to `true`, and enables the use of a small model to block uploading
+of NSFW images. Set it to `false` to skip NSFW moderation and model initialization. Empty or
+unrecognized values keep checks enabled.
 
 ## Running with Docker
 
+### RustFS for local development
+
+Start the local object store and initialize the image upload bucket:
+
+```sh
+docker compose --env-file conf/rustfs.env -f compose.rustfs.yaml up -d
+```
+
+Add the settings from `conf/rustfs.env` to your local `.env`, then restart the bot running on
+your host. RustFS serves the S3 API at `http://127.0.0.1:9000` and its console at
+`http://127.0.0.1:9001`. Log into the console with the access key and secret key from
+`conf/rustfs.env`. Both ports bind to localhost. The named data volume persists across restarts.
+
+The initializer creates `reminder-images` if needed and permits anonymous reads of its
+`uploads/` objects. Uploads, deletes and bucket listing require credentials. These settings
+enable dashboard image uploads locally; `NSFW_CHECK_ENABLED` keeps its configured value.
+`S3_ENDPOINT` uses path-style addressing for RustFS, and `S3_PUBLIC_URL` includes the bucket
+name because the browser fetches objects through that public URL.
+
+```sh
+docker compose --env-file conf/rustfs.env -f compose.rustfs.yaml logs rustfs-init
+docker compose --env-file conf/rustfs.env -f compose.rustfs.yaml down
+```
+
+`down` keeps the data volume. This development stack is separate from the bot/database stack
+below. The [RustFS Docker documentation](https://docs.rustfs.com/en/installation/container/docker)
+describes the upstream container configuration.
+
 A `compose.yml` file is provided to aid in running the bot agnostically using docker.
 
-* Populate a `.env` file as in `conf/default.env`
-* Add the additional variable `ROCKET_SECRET_KEY` with a key generated from
-  `head -c64 /dev/urandom | base64`
-* Run `docker compose up`
+-   Populate a `.env` file as in `conf/default.env`
+-   Add the additional variable `ROCKET_SECRET_KEY` with a key generated from
+    `head -c64 /dev/urandom | base64`
+-   Run `docker compose up`
 
 Please note that this is _not_ production-ready when run via compose. We do not offer a way for
 backing up of your data, or a way to run the dashboard securely via HTTPS, which is required for