"there is no reactor running, must be called from the context of a Tokio 1.x runtime" when using mongodb 2 with actix-web 3

Question

I tried to implement mongodb with actix web. This is my main class:

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    let db_helper = DbHelper::open_connection().await?;
    println!("Connected!");
     Ok(())
}

// my db helper
pub async fn open_connection() -> std::io::Result<DbHelper> {
    let client = Client::with_uri_str("mongodb://localhost:27017/").await.expect("connect to mongodb issue!");
    // List the names of the databases in that deployment.
    let databases = client.list_database_names(None, None).await.expect("Test error");
    for mongodb in databases {
        println!("{}", mongodb);
    }
    let database = client.database(DB_NAME);
    let db_helper = DbHelper {
        client,
        database,
    };
    Ok(db_helper)
}

When I tried to run this code, it gave me an error:

thread 'main' panicked at 'there is no reactor running, must be called from the context of a Tokio 1.x runtime',

The problem is from this line: let databases = client.list_database_names(None, None).await.expect("Test error");. I don't know what happened here. If I remove that line or replace actix_web::main with #[tokio::main], it can work. However, the actix web cannot work.

actix-web = "3"
mongodb = "2.0.0-beta.2"

What versions of actix-web and mongodb client are you running? — moy2010, Jul 27 '21 at 11:06
Similar problem: https://github.com/actix/actix-web/issues/2155, tokio versions are different on both dependency (mongodb client, actix) — Ömer Erden, Jul 27 '21 at 11:19

score 4 · Accepted Answer · answered Jul 27 '21 at 15:59

4

The problem is that you are using Actix web 3.x with Tokio 1.x and mongoDB client 2.x. You need to use Actix web 4.x for it to work with the other two.

answered Jul 27 '21 at 15:59

moy2010

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"there is no reactor running, must be called from the context of a Tokio 1.x runtime" when using mongodb 2 with actix-web 3

1 Answers1