carapace_lb 0.1.0

Carapace LB is a path-based load balancer that leverages the Pingora Framework by Cloudflare to manage and route traffic efficiently.
Documentation 
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use async_trait::async_trait;
use pingora::lb::discovery::ServiceDiscovery;
use std::collections::BTreeSet;
use std::collections::HashMap;
use pingora::protocols::l4::socket::SocketAddr;
use pingora::lb::Backend;
use pingora::prelude::Result;
use crate::docker::DockerService;
use crate::config::{Config, ProxyService};
use crate::routes::{BackendMapping, Routes};

/// The service discovery instance having config as its properties it also inherits the Service Discovery trait.
pub struct SD {
    pub config: Config
}
#[async_trait]
impl ServiceDiscovery for SD {
    async fn discover(&self) -> Result<(BTreeSet<Backend>, HashMap<u64,bool>)> {
        let docker_service: DockerService = DockerService::new().await;
        let proxy_services: Vec<ProxyService> = self.config.proxy_services.clone();
        let mut backends: BTreeSet<Backend> = BTreeSet::new();
        let backend_routes: Routes = Routes::new(self.config.load_balancer.routes_path.clone());
        let mut backend_mapping: Vec<BackendMapping> = Vec::new();
        for ps in proxy_services {  
            let port: u16 = ps.port; 
            let path: String = ps.path;  
            if ps.use_container {     
                let containers = docker_service.containers(HashMap::from([(
                    "label".to_string(),
                    Vec::from([format!("{}={}",ps.container_label_key,ps.container_label_value)])
                )])).await;            
                for container in containers {
                    let container_ip_address: String = docker_service.container_ip_address(&container).await;
                    if container_ip_address.is_empty() {
                        panic!("CONTAINER_NO_IP_ADDRESS: {}",container.id.unwrap());
                    }
                    let addr_string: String = format!("{}:{}",container_ip_address,port);
                    let addr: SocketAddr = self.to_socket_addr(container_ip_address,port);
                    let backend = Backend { addr, weight: 1};
                    backend_mapping.push(BackendMapping{
                        addr: addr_string,
                        path: path.clone()
                    });
                    backends.insert(backend);
                }
            }
            else{                
                let addr_string: String = format!("{}:{}",ps.host.clone(),port);  
                let addr: SocketAddr = self.to_socket_addr(ps.host,port);
                let backend = Backend { addr, weight: 1 };
                backend_mapping.push(BackendMapping{
                    addr: addr_string,
                    path: path.clone()
                });
                backends.insert(backend);
                
            }
        }
        backend_routes.write(backend_mapping);
        Ok((backends, HashMap::new()))
    }
}

impl SD {
    fn to_socket_addr(&self,host: String, port: u16) -> SocketAddr {
        let addr_string: String = format!("{}:{}",host,port);  
        let addr: SocketAddr = addr_string.parse::<SocketAddr>().unwrap_or_else(|error| {
            panic!("SERVICE_DISCOVERY_SOCKET_ADDR_PARSE_ERROR: {:?}",error);
        });
        addr
    }
}