cli: add a utility function for initializing tracing

Refactor the tracing initialization code into a utility function, so
that it can be shared with future CLIs that we'll add.

Signed-off-by: Omer Tuchfeld <[email protected]>

Author: omertuc

Cargo.lock

@@ -19,10 +19,10 @@ platforms = ["x86_64-unknown-linux-gnu", "aarch64-unknown-linux-gnu", "powerpc64
 anyhow = { workspace = true }
 bootc-lib = { version = "1.0", path = "../lib" }
 clap = { workspace = true }
+bootc-utils = { path = "../utils" }
 tokio = { workspace = true, features = ["macros"] }
 log = "0.4.21"
 tracing = { workspace = true }
-tracing-subscriber = { version = "0.3.18", features = ["env-filter"] }
 
 [lints]
 workspace = true

cli/Cargo.toml

@@ -1,25 +1,14 @@
 //! The main entrypoint for bootc, which just performs global initialization, and then
 //! calls out into the library.
-
 use anyhow::Result;
 
 /// The code called after we've done process global init and created
 /// an async runtime.
 async fn async_main() -> Result<()> {
-    // Don't include timestamps and such because they're not really useful and
-    // too verbose, and plus several log targets such as journald will already
-    // include timestamps.
-    let format = tracing_subscriber::fmt::format()
-        .without_time()
-        .with_target(false)
-        .compact();
-    // Log to stderr by default
-    tracing_subscriber::fmt()
-        .with_env_filter(tracing_subscriber::EnvFilter::from_default_env())
-        .event_format(format)
-        .with_writer(std::io::stderr)
-        .init();
-    tracing::trace!("starting");
+    bootc_utils::initialize_tracing();
+
+    tracing::trace!("starting bootc");
+
     // As you can see, the role of this file is mostly to just be a shim
     // to call into the code that lives in the internal shared library.
     bootc_lib::cli::run_from_iter(std::env::args()).await

cli/src/main.rs

@@ -14,6 +14,7 @@ serde_json = { workspace = true }
 tempfile = { workspace = true }
 tracing = { workspace = true }
 tokio = { workspace = true, features = ["process"] }
+tracing-subscriber = { version = "0.3.18", features = ["env-filter"] }
 
 [dev-dependencies]
 similar-asserts = { workspace = true }

utils/Cargo.toml

@@ -3,4 +3,6 @@
 //! "core" crates.
 //!
 mod command;
+mod tracing_util;
 pub use command::*;
+pub use tracing_util::*;

utils/src/lib.rs

@@ -0,0 +1,18 @@
+//! Helpers related to tracing, used by main entrypoints
+
+/// Initialize tracing with the default configuration.
+pub fn initialize_tracing() {
+    // Don't include timestamps and such because they're not really useful and
+    // too verbose, and plus several log targets such as journald will already
+    // include timestamps.
+    let format = tracing_subscriber::fmt::format()
+        .without_time()
+        .with_target(false)
+        .compact();
+    // Log to stderr by default
+    tracing_subscriber::fmt()
+        .with_env_filter(tracing_subscriber::EnvFilter::from_default_env())
+        .event_format(format)
+        .with_writer(std::io::stderr)
+        .init();
+}