--- title: "Pushing logs with a logging library - Rust - gelf_logger and log4rs-gelf" url: https://docs.ovhcloud.com/it/guides/manage-and-operate/observability/logs-data-platform/rust-libs lang: it lastUpdated: 2024-08-07 --- # Pushing logs with a logging library - Rust - gelf_logger and log4rs-gelf ## Objective This guide will explain how to push your logs to Logs Data Platform using Rust with two differents libraries. Use the one you prefer. Rust has a logging implementation ([log](https://docs.rs/log/*/log/)) which is widely used. OVHcloud has implemented this system to support the [GELF format](https://go2docs.graylog.org/4-x/getting_in_log_data/gelf.html?tocpath=Getting%20in%20Log%20Data%7CLog%20Sources%7CGELF%7C_____0#GELFPayloadSpecification#gelf-payload-specification): - **gelf\_logger**: This is a minimal logger. - **log4rs-gelf**: Based on _gelf\_logger_, this implementation is compatible with the complex configurable framework [log4rs](https://docs.rs/log4rs/*/log4rs/). Those loggers will: - serialize log entries using the serde\_gelf crate. - bufferize the result into memory. - batch send over network using TCP/TLS. - ensure fields follow the [LDP naming conventions](/it/guides/manage-and-operate/observability/logs-data-platform/field-naming-conventions.md). ## Requirements To complete this guide you will need: - Rust. We recommend the last stable version. - [An activated Logs Data Platform account.](https://www.ovh.com/fr/order/express/#/new/express/resume?products=~%28~%28planCode~%27logs-account~productId~%27logs%29) - [To create at least one Stream and get its token.](/it/guides/manage-and-operate/observability/logs-data-platform/getting-started-quick-start.md) - To install the [**serde**](https://serde.rs/) crate with the **derive** feature. - To install the [**log**](https://crates.io/crates/log) crate with the **serde** feature. ## Instructions ### First method: gelf\_logger You can install the **gelf\_logger** crate by adding the dependency to your `Cargo.toml`: ```toml [dependencies] gelf_logger = { version = "0.3.0", features = ["ovh-ldp"] } ``` Alternatively, the following cargo command will install it: ```bash $ cargo add gelf_logger -F ovh-ldp ``` Here is a full main.rs file showing how to use the **log** and the **gelf\_logger** API. ```rust use gelf_logger::{ gelf_alert, gelf_critical, gelf_debug, gelf_emergency, gelf_error, gelf_info, gelf_log, gelf_notice, gelf_warn, Builder, GelfLevel, }; use log::{error, info, warn, LevelFilter}; use serde::Serialize; #[derive(Serialize, Debug)] struct Request<'a> { id: u16, method: &'a str, path: &'a str, } fn main() { Builder::new() .filter_level(LevelFilter::Info) .ovh_ldp( "``".to_owned(), "``".to_owned(), ) .init(); // basic logs info!("hello from rust"); // Basic key-value logs. info!(count = 5; "packet received"); warn!(user = "foo"; "unknown user"); error!(err:err = "abc".parse::``().unwrap_err(); "parse error"); let req = Request { id: 42, method: "GET", path: "/login", }; // Will serialize as a `Debug` string. info!(req:?; "incoming request"); // Will flatten all the field and add them as additional fields. info!(req:serde; "incoming request flattened"); // Gelf specific levels. gelf_log!(GelfLevel::Emergency, foo = "bar"; "an emergency log"); gelf_emergency!(foo = "bar"; "an emergency log"); gelf_alert!(foo = "bar"; "an alert log"); gelf_critical!(foo = "bar"; "a critical log"); gelf_error!(foo = "bar"; "an error log"); gelf_warn!(foo = "bar"; "a warn log"); gelf_notice!(foo = "bar"; "a notice log"); gelf_info!(foo = "bar"; "an info log"); gelf_debug!(foo = "bar"; "a debug log"); // Flush underlying TCP socket. // This will only flush. The socket may be dropped without proper closing. log::logger().flush(); } ``` Don't forget to modify the placeholder **``** to the cluster where your stream resides. There is no need to put the Gelf port. Example: "gra3.logs.ovh.com". Don't forget to modify the placeholder **``** to the actual value of the write token of your stream. You could also look at the [generated API documentaton](https://docs.rs/gelf_logger/*). ### Second method: log4rs-gelf This method is an alternative to the previous one. Please consider the following as a different rust project. You need to be familiar with the [log4rs framework](https://docs.rs/log4rs/latest/log4rs/) Install **log4rs** and **log4rs-gelf** in your Rust project. Here is the modified Cargo.toml file: ```toml [dependencies] log = { version = "0.4.22", features = ["serde"] } log4rs = "1.3.0" log4rs-gelf = { version = "0.1.4", features = ["ovh-ldp"] } serde = { version = "1.0.204", features = ["derive"] } ``` Alternatively, use the following cargo commands: ```bash $ cargo add log4rs ``` ```bash $ cargo add log4rs-gelf -F ovh-ldp ``` #### Examples ##### From a YAML configuration file Copy the content of this yaml file in a file **log4rs.yaml**. This file will be retrieved by the rust program to configure the framework. ```yaml appenders: stdout: kind: console ldp: additional_fields: X-OVH-TOKEN: `` component: rust-cs buffer_duration: 5 buffer_size: 5 hostname: `` kind: buffer level: Informational null_character: true port: 12202 use_tls: true root: appenders: - ldp - stdout level: info ``` Don't forget to replace the placeholder **``** with the cluster where your stream resides. There is no need to put the Gelf port. Example: "gra3.logs.ovh.com". Don't forget to replace the placeholder **``** with the actual value of the write token of your stream Replace the X-OVH-TOKEN value with your X-OVH-TOKEN stream value and the hostname with your cluster. Use this configuration in your project: ```rust use core::time; use std::thread::sleep; use log::{info, warn}; fn main() { // reading log4rs_gelf::init_file("./log4rs.yml", None).unwrap(); // using log crate APIs info!("Hello from rust"); warn!("Warning from rust"); // simulating some work (log framework is asynchronous) sleep(time::Duration::from_secs(5)); // flushing remaining logs log4rs_gelf::flush().expect("Failed to send buffer, log records could be lost !"); } ``` You could also look at the [generated API documentation](https://docs.rs/log4rs-gelf/*). ## Go further - Getting Started: [Quick Start](/it/guides/manage-and-operate/observability/logs-data-platform/getting-started-quick-start.md) - Documentation: Guides - Community hub: [community of users](https://community.ovhcloud.com/) - Create an account: [Try it!](https://www.ovhcloud.com/en-gb/identity-security-operations/logs-data-platform/)