LDAP search and modify in Rust

LDAP.rs

use ldap3::{LdapConnAsync, Mod, SearchEntry, Scope};
use std::collections::HashSet;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // 1. Connect to the server
    let (conn, mut ldap) = LdapConnAsync::new("ldap://localhost:389").await?;
    ldap3::drive!(conn);

    // 2. Bind (Authenticate)
    ldap.simple_bind("cn=admin,dc=example,dc=org", "adminpassword").await?;

    let user_uid = "jdoe";
    let new_role = "Engineering_Lead";

    // 3. Search for the user's DN
    let (rs, _res) = ldap.search(
        "dc=example,dc=org",
        Scope::Subtree,
        &format!("(uid={})", user_uid),
        vec!["dn", "description"] // description often holds roles/notes
    ).await?.success()?;

    if rs.is_empty() {
        println!("User not found.");
        return Ok(());
    }

    // Get the first match
    let entry = SearchEntry::construct(rs[0].clone());
    let user_dn = entry.dn;

    println!("Found DN: {}", user_dn);

    // 4. Update (Add a role)
    // We use Mod::Add to append to an existing multi-valued attribute
    let mods = vec![
        Mod::Add("description", HashSet::from([new_role.to_string()]))
    ];

    let modify_res = ldap.modify(&user_dn, mods).await?.success();

    match modify_res {
        Ok(_) => println!("Successfully added role: {}", new_role),
        Err(e) => eprintln!("Failed to update: {:?}", e),
    }

    ldap.unbind().await?;
    Ok(())
}