feat: Google Logging support

Cargo.toml

@@ -26,6 +26,11 @@ documentation = "https://github.com/bolcom/unFTP"
 path = "crates/redislog"
 version = "0.1.2"
 
+[dependencies.googlelog]
+path = "crates/googlelog"
+features = ["shipper"]
+version = "0.1.0"
+
 [dependencies]
 async-trait = "0.1.80"
 base64 = "0.22.1"

crates/googlelog/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "googlelog"
+version = "0.1.0"
+edition = "2021"
+authors = [
+    "Rob klein Gunnewiek <[email protected]>"
+]
+
+[features]
+shipper = []
+
+[dependencies]
+google-logging2 = "5.0.5"
+serde_json = "1.0.117"
+chrono = "0.4.38"
+tokio = { version = "1.38.0", features = ["macros", "time", "rt-multi-thread"] }
+slog = "2.7.0"
+thiserror = "1.0.61"
+reqwest = { version = "0.12.5", default-features = false, features = ["rustls-tls", "json"] }

crates/googlelog/src/error.rs

@@ -0,0 +1,40 @@
+use thiserror;
+
+use reqwest::{self, StatusCode};
+
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error("Failed to read the 'default_labels' object from the JSON file, does it exist by this name?. Parse error: {0}")]
+    DefaultLabelsError(serde_json::Error),
+    #[error("Failed to read the 'resource_labels' object from the JSON file, does it exist by this name?. Parse error: {0}")]
+    ResourceLabelsError(serde_json::Error),
+    #[error("Serde JSON serialization failed with context '{context}'. Error: {source}")]
+    ShipperSerializeError {
+        context: String,
+        source: serde_json::Error,
+    },
+    #[error("Reqwest error with context '{context}'. Error: {source}")]
+    ShipperReqwestError {
+        context: String,
+        source: reqwest::Error,
+    },
+    #[error("No 'access_token' found in the metadata server response body")]
+    ShipperTokenNotFound,
+    #[error("No 'expires_in' found in the metadata server response body")]
+    ShipperTokenExpiryNotFound,
+    #[error("unsuccessful HTTP response error with context '{context}'. HTTP status code: '{status}', body: '{body}'")]
+    HttpResponseError {
+        context: String,
+        status: StatusCode,
+        body: String,
+    },
+}
+
+impl From<reqwest::Error> for Error {
+    fn from(err: reqwest::Error) -> Self {
+        Self::ShipperReqwestError {
+            context: "Error sending HTTP request".to_string(),
+            source: err,
+        }
+    }
+}

crates/googlelog/src/lib.rs

@@ -0,0 +1,27 @@
+//! An implemention of [`slog::Drain`](https://slog-rs.github.io/slog/slog/trait.Drain.html) for logging to [Google Cloud](https://cloud.google.com/logging).
+//!
+//! # Usage
+//!
+//! Warning: Currently, this library only works in the context of [workload identity](https://cloud.google.com/iam/docs/workload-identity-federation).
+//!
+//! The `googlelog` drain creates log entries compatible with [Google Cloud Logging](https://cloud.google.com/logging).
+//! Depending on how you want to ship these logs to the Google Logging API, you can choose from one of the available build methods.
+//!
+//! Start by configuring the Logger with the builder ([`Builder`](logger::Builder::new)) and selecting the appropriate build method based on your shipping requirements:
+//!
+//! 1. [`build()`](logger::Builder::build): Receives [`WriteLogEntries`](https://cloud.google.com/logging/docs/reference/v2/rpc/google.logging.v2#google.logging.v2.LoggingServiceV2.WriteLogEntries) over a channel and allows you to handle the transportation manually.
+//! 2. [`build_with_async_shipper()`](logger::Builder::build_with_async_shipper): Offloads transportation to the [`Shipper`](shipper::Shipper) and its sync-async Bridge in an async context. (Requires the `shipper` feature.)
+
+//!
+//! The [`builder`](struct@logger::Builder) supports several `with_*` methods to customize the log message format,
+//! particularly the default labels attached to [log entries](https://cloud.google.com/logging/docs/reference/v2/rest/v2/LogEntry).
+//!
+/// Googlelog Error types
+pub mod error;
+
+/// The [`slog::Drain`](https://slog-rs.github.io/slog/slog/trait.Drain.html) Implementation of the slog Drain for [Google Cloud Logging](https://cloud.google.com/logging)
+pub mod logger;
+
+/// An optional async process to ship the log for you
+#[cfg(feature = "shipper")]
+pub mod shipper;