Modify todo example to use postgres and diesel_async

Author: ThouCheese

examples/todo/Cargo.toml

@@ -7,16 +7,16 @@ publish = false
 
 [dependencies]
 rocket = { path = "../../core/lib" }
-diesel = { version = "2.0.0", features = ["sqlite", "r2d2"] }
+diesel = { version = "2.0.0", features = ["postgres", "r2d2"] }
 diesel_migrations = "2.0.0"
 
 [dev-dependencies]
 parking_lot = "0.12"
 rand = "0.8"
 
-[dependencies.rocket_sync_db_pools]
-path = "../../contrib/sync_db_pools/lib/"
-features = ["diesel_sqlite_pool"]
+[dependencies.rocket_db_pools]
+path = "../../contrib/db_pools/lib/"
+features = ["diesel_postgres"]
 
 [dependencies.rocket_dyn_templates]
 path = "../../contrib/dyn_templates"

examples/todo/Rocket.toml

@@ -1,5 +1,7 @@
 [default]
 template_dir = "static"
 
-[default.databases.sqlite_database]
-url = "db/db.sqlite"
+[default.databases.epic_todo_database]
+url = "postgresql://postgres@localhost:5432/epic_todo_database"
+max_connections = 1
+connect_timeout = 5

examples/todo/db/DB_LIVES_HERE

@@ -0,0 +1 @@
+db does not live here :(

examples/todo/src/main.rs

@@ -1,6 +1,4 @@
 #[macro_use] extern crate rocket;
-#[macro_use] extern crate rocket_sync_db_pools;
-#[macro_use] extern crate diesel;
 
 #[cfg(test)]
 mod tests;
@@ -13,13 +11,15 @@ use rocket::response::{Flash, Redirect};
 use rocket::serde::Serialize;
 use rocket::form::Form;
 use rocket::fs::{FileServer, relative};
+use rocket_db_pools::{Connection, Database};
 
 use rocket_dyn_templates::Template;
 
 use crate::task::{Task, Todo};
 
-#[database("sqlite_database")]
-pub struct DbConn(diesel::SqliteConnection);
+#[derive(Database)]
+#[database("epic_todo_database")]
+pub struct Db(rocket_db_pools::diesel::PgPool);
 
 #[derive(Debug, Serialize)]
 #[serde(crate = "rocket::serde")]
@@ -29,14 +29,14 @@ struct Context {
 }
 
 impl Context {
-    pub async fn err<M: std::fmt::Display>(conn: &DbConn, msg: M) -> Context {
+    pub async fn err<M: std::fmt::Display>(conn: &mut Connection<Db>, msg: M) -> Context {
         Context {
             flash: Some(("error".into(), msg.to_string())),
             tasks: Task::all(conn).await.unwrap_or_default()
         }
     }
 
-    pub async fn raw(conn: &DbConn, flash: Option<(String, String)>) -> Context {
+    pub async fn raw(conn: &mut Connection<Db>, flash: Option<(String, String)>) -> Context {
         match Task::all(conn).await {
             Ok(tasks) => Context { flash, tasks },
             Err(e) => {
@@ -51,11 +51,11 @@ impl Context {
 }
 
 #[post("/", data = "<todo_form>")]
-async fn new(todo_form: Form<Todo>, conn: DbConn) -> Flash<Redirect> {
+async fn new(todo_form: Form<Todo>, mut conn: Connection<Db>) -> Flash<Redirect> {
     let todo = todo_form.into_inner();
     if todo.description.is_empty() {
         Flash::error(Redirect::to("/"), "Description cannot be empty.")
-    } else if let Err(e) = Task::insert(todo, &conn).await {
+    } else if let Err(e) = Task::insert(todo, &mut conn).await {
         error_!("DB insertion error: {}", e);
         Flash::error(Redirect::to("/"), "Todo could not be inserted due an internal error.")
     } else {
@@ -64,50 +64,55 @@ async fn new(todo_form: Form<Todo>, conn: DbConn) -> Flash<Redirect> {
 }
 
 #[put("/<id>")]
-async fn toggle(id: i32, conn: DbConn) -> Result<Redirect, Template> {
-    match Task::toggle_with_id(id, &conn).await {
+async fn toggle(id: i32, mut conn: Connection<Db>) -> Result<Redirect, Template> {
+    match Task::toggle_with_id(id, &mut conn).await {
         Ok(_) => Ok(Redirect::to("/")),
         Err(e) => {
             error_!("DB toggle({}) error: {}", id, e);
-            Err(Template::render("index", Context::err(&conn, "Failed to toggle task.").await))
+            Err(Template::render("index", Context::err(&mut conn, "Failed to toggle task.").await))
         }
     }
 }
 
 #[delete("/<id>")]
-async fn delete(id: i32, conn: DbConn) -> Result<Flash<Redirect>, Template> {
-    match Task::delete_with_id(id, &conn).await {
+async fn delete(id: i32, mut conn: Connection<Db>) -> Result<Flash<Redirect>, Template> {
+    match Task::delete_with_id(id, &mut conn).await {
         Ok(_) => Ok(Flash::success(Redirect::to("/"), "Todo was deleted.")),
         Err(e) => {
             error_!("DB deletion({}) error: {}", id, e);
-            Err(Template::render("index", Context::err(&conn, "Failed to delete task.").await))
+            Err(Template::render("index", Context::err(&mut conn, "Failed to delete task.").await))
         }
     }
 }
 
 #[get("/")]
-async fn index(flash: Option<FlashMessage<'_>>, conn: DbConn) -> Template {
+async fn index(flash: Option<FlashMessage<'_>>, mut conn: Connection<Db>) -> Template {
     let flash = flash.map(FlashMessage::into_inner);
-    Template::render("index", Context::raw(&conn, flash).await)
+    Template::render("index", Context::raw(&mut conn, flash).await)
 }
 
 async fn run_migrations(rocket: Rocket<Build>) -> Rocket<Build> {
+    use diesel::Connection;
     use diesel_migrations::{embed_migrations, EmbeddedMigrations, MigrationHarness};
 
     const MIGRATIONS: EmbeddedMigrations = embed_migrations!("migrations");
+    let config: rocket_db_pools::Config = dbg!(rocket.figment()).extract_inner("databases.epic_todo_database").expect("Db not configured");
 
-    DbConn::get_one(&rocket).await
-        .expect("database connection")
-        .run(|conn| { conn.run_pending_migrations(MIGRATIONS).expect("diesel migrations"); })
-        .await;
+    rocket::tokio::task::spawn_blocking(move || {
+        diesel::PgConnection::establish(&config.url)
+            .expect("No database")
+            .run_pending_migrations(MIGRATIONS)
+            .expect("Invalid migrations");
+    })
+    .await.expect("tokio doesn't work");
 
     rocket
 }
 
 #[launch]
 fn rocket() -> _ {
     rocket::build()
-        .attach(DbConn::fairing())
+        .attach(Db::init())
         .attach(Template::fairing())
         .attach(AdHoc::on_ignite("Run Migrations", run_migrations))
         .mount("/", FileServer::from(relative!("static")))

examples/todo/src/task.rs

@@ -1,8 +1,9 @@
 use rocket::serde::Serialize;
 use diesel::{self, result::QueryResult, prelude::*};
+use rocket_db_pools::diesel::RunQueryDsl;
 
 mod schema {
-    table! {
+    diesel::table! {
         tasks {
             id -> Nullable<Integer>,
             description -> Text,
@@ -13,7 +14,7 @@ mod schema {
 
 use self::schema::tasks;
 
-use crate::DbConn;
+type DbConn = rocket_db_pools::diesel::AsyncPgConnection;
 
 #[derive(Serialize, Queryable, Insertable, Debug, Clone)]
 #[serde(crate = "rocket::serde")]
@@ -31,41 +32,35 @@ pub struct Todo {
 }
 
 impl Task {
-    pub async fn all(conn: &DbConn) -> QueryResult<Vec<Task>> {
-        conn.run(|c| {
-            tasks::table.order(tasks::id.desc()).load::<Task>(c)
-        }).await
+    pub async fn all(conn: &mut DbConn) -> QueryResult<Vec<Task>> {
+        tasks::table.order(tasks::id.desc()).load::<Task>(conn).await
     }
 
     /// Returns the number of affected rows: 1.
-    pub async fn insert(todo: Todo, conn: &DbConn) -> QueryResult<usize> {
-        conn.run(|c| {
-            let t = Task { id: None, description: todo.description, completed: false };
-            diesel::insert_into(tasks::table).values(&t).execute(c)
-        }).await
+    pub async fn insert(todo: Todo, conn: &mut DbConn) -> QueryResult<usize> {
+        let t = Task { id: None, description: todo.description, completed: false };
+        diesel::insert_into(tasks::table).values(&t).execute(conn).await
     }
 
     /// Returns the number of affected rows: 1.
-    pub async fn toggle_with_id(id: i32, conn: &DbConn) -> QueryResult<usize> {
-        conn.run(move |c| {
-            let task = tasks::table.filter(tasks::id.eq(id)).get_result::<Task>(c)?;
-            let new_status = !task.completed;
-            let updated_task = diesel::update(tasks::table.filter(tasks::id.eq(id)));
-            updated_task.set(tasks::completed.eq(new_status)).execute(c)
-        }).await
+    pub async fn toggle_with_id(id: i32, conn: &mut DbConn) -> QueryResult<usize> {
+        let task = tasks::table.filter(tasks::id.eq(id)).get_result::<Task>(conn).await?;
+        let new_status = !task.completed;
+        let updated_task = diesel::update(tasks::table.filter(tasks::id.eq(id)));
+        updated_task.set(tasks::completed.eq(new_status)).execute(conn).await
     }
 
     /// Returns the number of affected rows: 1.
-    pub async fn delete_with_id(id: i32, conn: &DbConn) -> QueryResult<usize> {
-        conn.run(move |c| diesel::delete(tasks::table)
+    pub async fn delete_with_id(id: i32, conn: &mut DbConn) -> QueryResult<usize> {
+        diesel::delete(tasks::table)
             .filter(tasks::id.eq(id))
-            .execute(c))
+            .execute(conn)
             .await
     }
 
     /// Returns the number of affected rows.
     #[cfg(test)]
-    pub async fn delete_all(conn: &DbConn) -> QueryResult<usize> {
-        conn.run(|c| diesel::delete(tasks::table).execute(c)).await
+    pub async fn delete_all(conn: &mut DbConn) -> QueryResult<usize> {
+        diesel::delete(tasks::table).execute(conn).await
     }
 }

examples/todo/src/tests.rs

@@ -4,6 +4,7 @@ use rand::{Rng, thread_rng, distributions::Alphanumeric};
 
 use rocket::local::asynchronous::Client;
 use rocket::http::{Status, ContentType};
+use rocket_db_pools::Database;
 
 // We use a lock to synchronize between tests so DB operations don't collide.
 // For now. In the future, we'll have a nice way to run each test in a DB
@@ -15,10 +16,14 @@ macro_rules! run_test {
         let _lock = DB_LOCK.lock();
 
         rocket::async_test(async move {
-            let $client = Client::tracked(super::rocket()).await.expect("Rocket client");
-            let db = super::DbConn::get_one($client.rocket()).await;
-            let $conn = db.expect("failed to get database connection for testing");
-            Task::delete_all(&$conn).await.expect("failed to delete all tasks for testing");
+            let rocket = super::rocket();
+            let mut $conn = super::Db::fetch(&rocket)
+                .expect("database")
+                .get()
+                .await
+                .expect("database connection");
+            let $client = Client::tracked(rocket).await.expect("Rocket client");
+            Task::delete_all(&mut $conn).await.expect("failed to delete all tasks for testing");
 
             $block
         })
@@ -39,7 +44,7 @@ fn test_index() {
 fn test_insertion_deletion() {
     run_test!(|client, conn| {
         // Get the tasks before making changes.
-        let init_tasks = Task::all(&conn).await.unwrap();
+        let init_tasks = Task::all(&mut conn).await.unwrap();
 
         // Issue a request to insert a new task.
         client.post("/todo")
@@ -49,7 +54,7 @@ fn test_insertion_deletion() {
             .await;
 
         // Ensure we have one more task in the database.
-        let new_tasks = Task::all(&conn).await.unwrap();
+        let new_tasks = Task::all(&mut conn).await.unwrap();
         assert_eq!(new_tasks.len(), init_tasks.len() + 1);
 
         // Ensure the task is what we expect.
@@ -61,7 +66,7 @@ fn test_insertion_deletion() {
         client.delete(format!("/todo/{}", id)).dispatch().await;
 
         // Ensure it's gone.
-        let final_tasks = Task::all(&conn).await.unwrap();
+        let final_tasks = Task::all(&mut conn).await.unwrap();
         assert_eq!(final_tasks.len(), init_tasks.len());
         if final_tasks.len() > 0 {
             assert_ne!(final_tasks[0].description, "My first task");
@@ -79,16 +84,16 @@ fn test_toggle() {
             .dispatch()
             .await;
 
-        let task = Task::all(&conn).await.unwrap()[0].clone();
+        let task = Task::all(&mut conn).await.unwrap()[0].clone();
         assert_eq!(task.completed, false);
 
         // Issue a request to toggle the task; ensure it is completed.
         client.put(format!("/todo/{}", task.id.unwrap())).dispatch().await;
-        assert_eq!(Task::all(&conn).await.unwrap()[0].completed, true);
+        assert_eq!(Task::all(&mut conn).await.unwrap()[0].completed, true);
 
         // Issue a request to toggle the task; ensure it's not completed again.
         client.put(format!("/todo/{}", task.id.unwrap())).dispatch().await;
-        assert_eq!(Task::all(&conn).await.unwrap()[0].completed, false);
+        assert_eq!(Task::all(&mut conn).await.unwrap()[0].completed, false);
     })
 }
 
@@ -98,7 +103,7 @@ fn test_many_insertions() {
 
     run_test!(|client, conn| {
         // Get the number of tasks initially.
-        let init_num = Task::all(&conn).await.unwrap().len();
+        let init_num = Task::all(&mut conn).await.unwrap().len();
         let mut descs = Vec::new();
 
         for i in 0..ITER {
@@ -119,7 +124,7 @@ fn test_many_insertions() {
             descs.insert(0, desc);
 
             // Ensure the task was inserted properly and all other tasks remain.
-            let tasks = Task::all(&conn).await.unwrap();
+            let tasks = Task::all(&mut conn).await.unwrap();
             assert_eq!(tasks.len(), init_num + i + 1);
 
             for j in 0..i {