Cargo.toml

@@ -7,7 +7,7 @@ edition = "2021"
 
 [dependencies]
 axum = "0.8.1"
-redis = { version = "0.23.3", features = ["tokio-comp"] }
 serde = { version = "1.0.188", features = ["derive"] }
 serde_json = "1.0.107"
+sqlx = { version = "0.8.3", features = ["runtime-tokio", "postgres"] }
 tokio = { version = "1.32.0", features = ["macros", "rt-multi-thread"] }

README.md

@@ -1,14 +1,48 @@
 # KOreader Sync Server
-This is a KOreader sync server, implemented in Rust. It uses the crates *axum*, *redis*, *serde* and *serde_json*.
+This is a KOreader sync server, implemented in Rust. It uses the crates *axum*, *sqlx*, *serde* and *serde_json*.
 
 ## Requirements
-- Rust toolchain (≥ 1.63) for compilation
-- A running Redis server
+- Rust toolchain for compilation
+- A running PostgreSQL server
 - Nginx (or Apache) webserver as a reverse proxy, since kosyncrs only listens locally and uses HTTP.
 
 ## Installation
-Just compile it with `cargo build --release`. You can then copy the executable for example to `/usr/local/bin/`. If you want to start the service automatically, you can adapt the example systemd file for your needs. You can also use nginx as a reverse proxy, so that the sync server listens on port 443.
+Just compile it with `cargo build --release`. You can then copy the executable for example to `/usr/local/bin/`.
 
-## Todo
-- Test, if it really works, and if it works reliably. Feedback is very welcome!
-- Make it more configurable
+If you want to start the service automatically, you can adapt the example systemd file for your needs. Please pay particularly attention to the PG_URL environment variable.You have to adjust the database username and password.
+
+You can also use nginx as a reverse proxy, so that the sync server listens on port 443. An example file is provided.
+
+### Database setup
+First, create a new database user and set a password:
+```
+$ createuser -P kosync
+```
+
+Then, create a new database which is owned by the newly created user:
+```
+$ createdb -O kosync kosync
+```
+
+Connect to the database as user *kosync* (with psql) and create the database tables:
+```sql
+CREATE TABLE users (
+  id BIGSERIAL PRIMARY KEY,
+  username TEXT NOT NULL,
+  password TEXT
+);
+
+CREATE TABLE progresses (
+  id BIGSERIAL PRIMARY KEY,
+  user_id BIGINT,
+  document TEXT UNIQUE NOT NULL,
+  progress TEXT NOT NULL,
+  percentage REAL NOT NULL,
+  device TEXT NOT NULL,
+  device_id TEXT NOT NULL,
+  timestamp BIGINT NOT NULL,
+  FOREIGN KEY (user_id)
+     REFERENCES users(id) ON DELETE CASCADE,
+  UNIQUE (user_id, document)
+);
+```

src/main.rs

@@ -1,12 +1,18 @@
 use axum::{
-    extract::Path, http::HeaderMap, http::StatusCode, routing::get, routing::post, routing::put,
+    extract::{Path, State},
+    http::HeaderMap,
+    http::StatusCode,
+    routing::get,
+    routing::post,
+    routing::put,
     Json, Router,
 };
-use redis::Commands;
 use serde::{Deserialize, Serialize};
 use serde_json::{json, Value};
+use sqlx::{postgres::PgPoolOptions, PgExecutor, PgPool};
 
-use std::time::{SystemTime, UNIX_EPOCH};
+use std::env;
+use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
 #[derive(Deserialize)]
 pub struct User {
@@ -30,11 +36,23 @@ pub struct GetProgress {
     percentage: f32,
     device: String,
     device_id: String,
-    timestamp: u64,
+    timestamp: i64,
 }
 
 #[tokio::main]
 async fn main() {
+    let pg_url: String = env::var("PG_URL")
+        .ok()
+        .and_then(|v| v.parse().ok())
+        .unwrap();
+
+    let db_pool = PgPoolOptions::new()
+        .max_connections(64)
+        .acquire_timeout(Duration::from_secs(5))
+        .connect(&pg_url)
+        .await
+        .expect("Can't connect to database.");
+
     // build our application with a single route
     let app = Router::new()
         .route("/", get(root))
@@ -42,10 +60,13 @@ async fn main() {
         .route("/users/auth", get(auth_user))
         .route("/syncs/progress", put(update_progress))
         .route("/syncs/progress/{document}", get(get_progress))
-        .route("/healthcheck", get(healthcheck));
+        .route("/healthcheck", get(healthcheck))
+        .with_state(db_pool);
 
     // run it with hyper on localhost:3003
-    let listener = tokio::net::TcpListener::bind("127.0.0.1:3003").await.unwrap();
+    let listener = tokio::net::TcpListener::bind("127.0.0.1:3003")
+        .await
+        .unwrap();
     axum::serve(listener, app).await.unwrap();
 }
 
@@ -53,19 +74,31 @@ async fn root() -> &'static str {
     "KOreader sync server"
 }
 
-async fn create_user(Json(payload): Json<User>) -> (StatusCode, Json<Value>) {
-    let client = redis::Client::open("redis://127.0.0.1/").unwrap();
-    let mut con = client.get_connection().unwrap();
+async fn create_user(
+    State(db_pool): State<PgPool>,
+    Json(payload): Json<User>,
+) -> (StatusCode, Json<Value>) {
+    //let client = redis::Client::open("redis://127.0.0.1/").unwrap();
+    //let mut con = client.get_connection().unwrap();
 
     let username = payload.username;
     let password = payload.password;
 
-    let user_key = format!("user:{username}:key");
+    let row: (i64,) = sqlx::query_as("SELECT COUNT(id) FROM users WHERE username = $1")
+        .bind(&username)
+        .fetch_one(&db_pool)
+        .await
+        .unwrap();
 
-    let does_exist: bool = con.exists(&user_key).unwrap();
+    let does_exist: bool = if row.0 >= 1 { true } else { false };
 
     if does_exist == false {
-        let _: () = con.set(&user_key, password).unwrap();
+        sqlx::query("INSERT INTO users (username, password) VALUES ($1, $2)")
+            .bind(&username)
+            .bind(&password)
+            .execute(&db_pool)
+            .await
+            .unwrap();
     } else {
         return (
             StatusCode::PAYMENT_REQUIRED,
@@ -76,110 +109,133 @@ async fn create_user(Json(payload): Json<User>) -> (StatusCode, Json<Value>) {
     (StatusCode::CREATED, Json(json!({ "username" : username })))
 }
 
-fn authorize(username: &str, password: &str) -> bool {
-    let client = redis::Client::open("redis://127.0.0.1/").unwrap();
-    let mut con = client.get_connection().unwrap();
-
+async fn authorize(db: impl PgExecutor<'_>, username: &str, password: &str) -> bool {
     if username.is_empty() || password.is_empty() {
         return false;
     }
 
-    let user_key = format!("user:{username}:key");
+    let row: Option<(String,)> = sqlx::query_as("SELECT password FROM users WHERE username = $1")
+        .bind(&username)
+        .fetch_optional(db)
+        .await
+        .unwrap();
 
-    let redis_pw: String = con.get(&user_key).unwrap();
-
-    if password != redis_pw {
-        return false;
+    if let Some(val) = row {
+        return password == val.0;
     }
 
-    true
+    false
 }
 
-async fn auth_user(headers: HeaderMap) -> (StatusCode, Json<Value>) {
+async fn auth_user(State(db_pool): State<PgPool>, headers: HeaderMap) -> (StatusCode, Json<Value>) {
     let username = headers["x-auth-user"].to_str().unwrap_or("");
     let password = headers["x-auth-key"].to_str().unwrap_or("");
 
-    if authorize(&username, &password) == false {
-        return (
+    let mut tx = db_pool.begin().await.unwrap();
+
+    if authorize(&mut *tx, username, password).await == true {
+        return (StatusCode::OK, Json(json!({"authorized" : "OK"})));
+    }
+
+    tx.commit().await.unwrap();
+
+    (
         StatusCode::UNAUTHORIZED,
         Json(json!({"message" : "Unauthorized"})),
-        );
+    )
 }
 
-    (StatusCode::OK, Json(json!({"authorized" : "OK"})))
-}
-
-async fn update_progress(headers: HeaderMap, Json(payload): Json<UpdateProgress>) -> StatusCode {
+async fn update_progress(
+    State(db_pool): State<PgPool>,
+    headers: HeaderMap,
+    Json(payload): Json<UpdateProgress>,
+) -> StatusCode {
     let username = headers["x-auth-user"].to_str().unwrap_or("");
     let password = headers["x-auth-key"].to_str().unwrap_or("");
 
-    if authorize(username, password) == false {
+    let mut tx = db_pool.begin().await.unwrap();
+
+    if authorize(&mut *tx, username, password).await == false {
         return StatusCode::UNAUTHORIZED;
     }
 
-    let client = redis::Client::open("redis://127.0.0.1/").unwrap();
-    let mut con = client.get_connection().unwrap();
+    tx.commit().await.unwrap();
 
     let timestamp = SystemTime::now()
         .duration_since(UNIX_EPOCH)
         .unwrap()
         .as_secs();
-    let document = payload.document;
 
-    let doc_key = format!("user:{username}:document:{document}");
-    let _: () = con
-        .hset_multiple(
-            &doc_key,
-            &[
-                ("percentage", &payload.percentage.to_string()),
-                ("progress", &payload.progress),
-                ("device", &payload.device),
-                ("device_id", &payload.device_id),
-                ("timestamp", &timestamp.to_string()),
-            ],
-        )
+    let row: (i64,) = sqlx::query_as("SELECT id FROM users WHERE username = $1")
+        .bind(&username)
+        .fetch_one(&db_pool)
+        .await
+        .unwrap();
+
+    let user_id = row.0;
+
+    sqlx::query("INSERT INTO progresses (user_id, document, progress, percentage, device, device_id, timestamp) VALUES ($1, $2, $3, $4, $5, $6, $7) \
+                    ON CONFLICT (user_id, document) DO UPDATE \
+                    SET user_id = $1, document = $2, progress = $3, percentage = $4, device = $5, device_id = $6, timestamp = $7")
+            .bind(user_id)
+            .bind(&payload.document)
+            .bind(&payload.progress)
+            .bind(&payload.percentage)
+            .bind(&payload.device)
+            .bind(&payload.device_id)
+            .bind(timestamp as i64)
+            .execute(&db_pool)
+            .await
             .unwrap();
 
     StatusCode::OK
 }
 
 async fn get_progress(
+    State(db_pool): State<PgPool>,
     headers: HeaderMap,
     Path(document): Path<String>,
 ) -> (StatusCode, Json<Value>) {
     let username = headers["x-auth-user"].to_str().unwrap_or("");
     let password = headers["x-auth-key"].to_str().unwrap_or("");
 
-    if authorize(username, password) == false {
+    let mut tx = db_pool.begin().await.unwrap();
+
+    if authorize(&mut *tx, username, password).await == false {
         return (StatusCode::UNAUTHORIZED, Json(json!("")));
     }
 
-    let client = redis::Client::open("redis://127.0.0.1/").unwrap();
-    let mut con = client.get_connection().unwrap();
+    tx.commit().await.unwrap();
 
-    let doc_key = format!("user:{username}:document:{document}");
+    let row: (i64,) = sqlx::query_as("SELECT id FROM users WHERE username = $1")
+        .bind(&username)
+        .fetch_one(&db_pool)
+        .await
+        .unwrap();
 
-    let values: Vec<String> = con
-        .hget(
-            doc_key,
-            &["percentage", "progress", "device", "device_id", "timestamp"],
-        )
-        .unwrap_or_default();
+    let user_id = row.0;
 
-    if values.is_empty() {
-        return (StatusCode::OK, Json(json!({})));
-    }
+    let row: Option<(f32, String, String, String, i64)> = sqlx::query_as("SELECT percentage, progress, device, device_id, timestamp FROM progresses WHERE user_id = $1 AND document = $2")
+        .bind(user_id)
+        .bind(&document)
+        .fetch_optional(&db_pool)
+        .await
+        .unwrap();
 
-    let res = GetProgress {
-        percentage: values[0].parse().unwrap(),
-        progress: values[1].clone(),
-        device: values[2].clone(),
-        device_id: values[3].clone(),
-        timestamp: values[4].parse().unwrap(),
+    if let Some(val) = row {
+        let progress = GetProgress {
+            percentage: val.0,
+            progress: val.1,
+            device: val.2,
+            device_id: val.3,
+            timestamp: val.4,
             document,
         };
 
-    (StatusCode::OK, Json(json!(res)))
+        return (StatusCode::OK, Json(json!(progress)));
+    }
+
+    (StatusCode::OK, Json(json!("")))
 }
 
 async fn healthcheck() -> (StatusCode, Json<Value>) {

systemd/kosyncrs.service

@@ -11,6 +11,7 @@ User=myuser
 Group=users
 WorkingDirectory=/home/myuser
 ExecStart=/usr/local/bin/kosyncrs
+Environment="PG_URL=postgresql://kosync:password@localhost/kosync"
 Restart=always
 
 [Install]