feat: add logging to client (#18)

Signed-off-by: Gaius <gaius.qi@gmail.com>

Cargo.toml

@@ -26,5 +26,7 @@ path = "src/bin/dfstore/main.rs"
 clap = { version = "4.1.13", features = [ "derive" ] }
 home = "0.5.4"
 tracing = "0.1"
-tracing-subscriber = "0.3"
+tracing-log = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+tracing-appender = "0.2"
 humantime = "2.1.0"

src/bin/dfget/main.rs

@@ -122,5 +122,5 @@ struct Args {
 
 fn main() {
     let args = Args::parse();
-    print!("{:?}", args.output);
+    println!("{:?}", args.output);
 }

src/logging/mod.rs

@@ -13,3 +13,37 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
+use tracing::Level;
+use tracing_appender::non_blocking::WorkerGuard;
+use tracing_appender::rolling::{RollingFileAppender, Rotation};
+use tracing_log::LogTracer;
+use tracing_subscriber::{fmt::Layer, prelude::*, EnvFilter, Registry};
+
+pub fn init_logging(name: &str, dir: &str, level: Level) -> Vec<WorkerGuard> {
+    let mut guards = vec![];
+    LogTracer::init().expect("failed to init LogTracer");
+
+    // Setup stdout layer.
+    let (stdout_writer, stdout_guard) = tracing_appender::non_blocking(std::io::stdout());
+    let stdout_logging_layer = Layer::new().with_writer(stdout_writer);
+    guards.push(stdout_guard);
+
+    // Setup file layer.
+    let rolling_appender = RollingFileAppender::new(Rotation::DAILY, dir, name);
+    let (rolling_writer, rolling_writer_guard) = tracing_appender::non_blocking(rolling_appender);
+    let file_logging_layer = Layer::new().with_writer(rolling_writer);
+    guards.push(rolling_writer_guard);
+
+    let env_filter =
+        EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new(level.to_string()));
+
+    let subscriber = Registry::default()
+        .with(env_filter)
+        .with(stdout_logging_layer)
+        .with(file_logging_layer);
+
+    tracing::subscriber::set_global_default(subscriber).expect("failed to set global subscriber");
+
+    guards
+}