proxmox-backup/proxmox-rest-server/examples/minimal-rest-server.rs

use std::collections::HashMap;
use std::future::Future;
use std::pin::Pin;
use std::sync::Mutex;

use anyhow::{bail, format_err, Error};
use http::request::Parts;
use http::HeaderMap;
use hyper::{Body, Method, Response};
use lazy_static::lazy_static;

use proxmox_router::{
    list_subdirs_api_method, Router, RpcEnvironmentType, SubdirMap, UserInformation,
};
use proxmox_schema::api;

use proxmox_rest_server::{ApiConfig, AuthError, RestEnvironment, RestServer, ServerAdapter};

// Create a Dummy User information system
struct DummyUserInfo;

impl UserInformation for DummyUserInfo {
    fn is_superuser(&self, _userid: &str) -> bool {
        // Always return true here, so we have access to everthing
        true
    }
    fn is_group_member(&self, _userid: &str, group: &str) -> bool {
        group == "Group"
    }
    fn lookup_privs(&self, _userid: &str, _path: &[&str]) -> u64 {
        u64::MAX
    }
}

struct MinimalServer;

// implement the server adapter
impl ServerAdapter for MinimalServer {
    // normally this would check and authenticate the user
    fn check_auth(
        &self,
        _headers: &HeaderMap,
        _method: &Method,
    ) -> Pin<
        Box<
            dyn Future<Output = Result<(String, Box<dyn UserInformation + Sync + Send>), AuthError>>
                + Send,
        >,
    > {
        Box::pin(async move {
            // get some global/cached userinfo
            let userinfo: Box<dyn UserInformation + Sync + Send> = Box::new(DummyUserInfo);
            // Do some user checks, e.g. cookie/csrf
            Ok(("User".to_string(), userinfo))
        })
    }

    // this should return the index page of the webserver, iow. what the user browses to
    fn get_index(
        &self,
        _env: RestEnvironment,
        _parts: Parts,
    ) -> Pin<Box<dyn Future<Output = Response<Body>> + Send>> {
        Box::pin(async move {
            // build an index page
            http::Response::builder()
                .body("hello world".into())
                .unwrap()
        })
    }
}

// a few examples on how to do api calls with the Router

#[api]
/// A simple ping method. returns "pong"
fn ping() -> Result<String, Error> {
    Ok("pong".to_string())
}

lazy_static! {
    static ref ITEM_MAP: Mutex<HashMap<String, String>> = Mutex::new(HashMap::new());
}

#[api]
/// Lists all current items
fn list_items() -> Result<Vec<String>, Error> {
    Ok(ITEM_MAP.lock().unwrap().keys().cloned().collect())
}

#[api(
    input: {
        properties: {
            name: {
                type: String,
                description: "The name",
            },
            value: {
                type: String,
                description: "The value",
            },
        },
    },
)]
/// creates a new item
fn create_item(name: String, value: String) -> Result<(), Error> {
    let mut map = ITEM_MAP.lock().unwrap();
    if map.contains_key(&name) {
        bail!("{} already exists", name);
    }

    map.insert(name, value);

    Ok(())
}

#[api(
    input: {
        properties: {
            name: {
                type: String,
                description: "The name",
            },
        },
    },
)]
/// returns the value of an item
fn get_item(name: String) -> Result<String, Error> {
    ITEM_MAP
        .lock()
        .unwrap()
        .get(&name)
        .map(|s| s.to_string())
        .ok_or_else(|| format_err!("no such item '{}'", name))
}

#[api(
    input: {
        properties: {
            name: {
                type: String,
                description: "The name",
            },
            value: {
                type: String,
                description: "The value",
            },
        },
    },
)]
/// updates an item
fn update_item(name: String, value: String) -> Result<(), Error> {
    if let Some(val) = ITEM_MAP.lock().unwrap().get_mut(&name) {
        *val = value;
    } else {
        bail!("no such item '{}'", name);
    }
    Ok(())
}

#[api(
    input: {
        properties: {
            name: {
                type: String,
                description: "The name",
            },
        },
    },
)]
/// deletes an item
fn delete_item(name: String) -> Result<(), Error> {
    if ITEM_MAP.lock().unwrap().remove(&name).is_none() {
        bail!("no such item '{}'", name);
    }
    Ok(())
}

const ITEM_ROUTER: Router = Router::new()
    .get(&API_METHOD_GET_ITEM)
    .put(&API_METHOD_UPDATE_ITEM)
    .delete(&API_METHOD_DELETE_ITEM);

const SUBDIRS: SubdirMap = &[
    (
        "items",
        &Router::new()
            .get(&API_METHOD_LIST_ITEMS)
            .post(&API_METHOD_CREATE_ITEM)
            .match_all("name", &ITEM_ROUTER),
    ),
    ("ping", &Router::new().get(&API_METHOD_PING)),
];

const ROUTER: Router = Router::new()
    .get(&list_subdirs_api_method!(SUBDIRS))
    .subdirs(SUBDIRS);

async fn run() -> Result<(), Error> {
    // we first have to configure the api environment (basedir etc.)

    let config = ApiConfig::new(
        "/var/tmp/",
        &ROUTER,
        RpcEnvironmentType::PUBLIC,
        MinimalServer,
    )?;
    let rest_server = RestServer::new(config);

    // then we have to create a daemon that listens, accepts and serves the api to clients
    proxmox_rest_server::daemon::create_daemon(
        ([127, 0, 0, 1], 65000).into(),
        move |listener| {
            let incoming = hyper::server::conn::AddrIncoming::from_listener(listener)?;

            Ok(async move {
                hyper::Server::builder(incoming).serve(rest_server).await?;

                Ok(())
            })
        },
        None,
    )
    .await?;

    Ok(())
}

fn main() -> Result<(), Error> {
    let rt = tokio::runtime::Runtime::new()?;
    rt.block_on(async { run().await })
}