feat: Re-configurable logger

Updates tracing to the latest version from GitHub adding
support for re-configuring the logger at run-time.

Signed-off-by: Jonathan Woollett-Light <jcawl@amazon.co.uk>

Author: Jonathan Woollett-Light

Cargo.lock

@@ -21,7 +21,7 @@ mmds = { path = "../mmds" }
 seccompiler = { path = "../seccompiler" }
 utils = { path = "../utils" }
 vmm = { path = "../vmm" }
-tracing = { version = "0.1.37", features = ["attributes"] }
+tracing = { git = "https://github.com/tokio-rs/tracing", rev = "27f688efb72316a26f3ec1f952c82626692c08ff", features = ["attributes"] }
 
 [dev-dependencies]
 libc = "0.2.117"

src/api_server/Cargo.toml

@@ -37,7 +37,7 @@ mod tests {
               }"#;
 
         let mut expected_cfg = LoggerConfig {
-            log_path: PathBuf::from("log"),
+            log_path: Some(PathBuf::from("log")),
             level: Some(Level::Warn),
             show_level: Some(false),
             show_log_origin: Some(false),
@@ -56,7 +56,7 @@ mod tests {
               }"#;
 
         expected_cfg = LoggerConfig {
-            log_path: PathBuf::from("log"),
+            log_path: Some(PathBuf::from("log")),
             level: Some(Level::Debug),
             show_level: Some(false),
             show_log_origin: Some(false),

src/api_server/src/request/logger.rs

@@ -17,7 +17,7 @@ libc = "0.2.147"
 serde = { version = "1.0.171", features = ["derive"] }
 serde_json = "1.0.100"
 thiserror = "1.0.43"
-tracing = { version = "0.1.37", features = ["attributes"] }
+tracing = { git = "https://github.com/tokio-rs/tracing", rev = "27f688efb72316a26f3ec1f952c82626692c08ff", features = ["attributes"] }
 
 vmm = { path = "../vmm" }
 

src/cpu-template-helper/Cargo.toml

@@ -11,7 +11,7 @@ bench = false
 [dependencies]
 bitflags = "1.3.2"
 derive_more = { version = "0.99.17", default-features = false, features = ["from"] }
-tracing = { version = "0.1.37", features = ["attributes"] }
+tracing = { git = "https://github.com/tokio-rs/tracing", rev = "27f688efb72316a26f3ec1f952c82626692c08ff", features = ["attributes"] }
 
 logger = { path = "../logger" }
 micro_http = { git = "https://github.com/firecracker-microvm/micro-http", rev = "4b18a04" }

src/dumbo/Cargo.toml

@@ -19,8 +19,8 @@ log = "0.4.19"
 serde_json = "1.0.100"
 thiserror = "1.0.43"
 timerfd = "1.5.0"
-tracing = { version = "0.1.37", features = ["attributes"] }
-tracing-subscriber = "0.3.17"
+tracing = { git = "https://github.com/tokio-rs/tracing", rev = "27f688efb72316a26f3ec1f952c82626692c08ff", features = ["attributes"] }
+tracing-subscriber = { git = "https://github.com/tokio-rs/tracing", rev = "27f688efb72316a26f3ec1f952c82626692c08ff" }
 
 api_server = { path = "../api_server" }
 logger = { path = "../logger" }

src/firecracker/Cargo.toml

@@ -127,6 +127,7 @@ pub(crate) fn run_with_api(
     api_payload_limit: usize,
     mmds_size_limit: usize,
     metadata_json: Option<&str>,
+    logger_handles: vmm::vmm_config::LoggerHandles,
 ) -> FcExitCode {
     // FD to notify of API events. This is a blocking eventfd by design.
     // It is used in the config/pre-boot loop which is a simple blocking loop
@@ -223,6 +224,7 @@ pub(crate) fn run_with_api(
             boot_timer_enabled,
             mmds_size_limit,
             metadata_json,
+            logger_handles,
         ),
     };
 

src/firecracker/src/api_server_adapter.rs

@@ -281,7 +281,8 @@ fn main_exitable() -> FcExitCode {
 
     logger::INSTANCE_ID.set(String::from(instance_id)).unwrap();
 
-    if let Some(log_path) = arguments.single_value("log-path") {
+    // Configure logger, the logger handles can be used to re-configure the logger with the API.
+    let logger_handles = {
         let level_res = arguments
             .single_value("level")
             .map(|s| Level::from_str(s))
@@ -297,18 +298,20 @@ fn main_exitable() -> FcExitCode {
             }
         };
 
-        let logger_config = vmm::vmm_config::LoggerConfig {
-            log_path: PathBuf::from(log_path),
+        let config = vmm::vmm_config::LoggerConfig {
+            log_path: arguments.single_value("log-path").map(PathBuf::from),
             level,
             show_level: Some(arguments.flag_present("show-level")),
             show_log_origin: Some(arguments.flag_present("show-log-origin")),
             new_format: Some(arguments.flag_present("new-format")),
         };
-
-        if let Err(err) = logger_config.init() {
-            return generic_error_exit(&format!("Could not initialize logger: {}", err));
-        };
-    }
+        match config.init() {
+            Ok(h) => h,
+            Err(err) => {
+                return generic_error_exit(&format!("Could not initialize logger: {}", err));
+            }
+        }
+    };
 
     if let Some(metrics_path) = arguments.single_value("metrics-path") {
         let metrics_config = MetricsConfig {
@@ -398,6 +401,7 @@ fn main_exitable() -> FcExitCode {
             api_payload_limit,
             mmds_size_limit,
             metadata_json.as_deref(),
+            logger_handles,
         )
     } else {
         let seccomp_filters: BpfThreadMap = seccomp_filters

src/firecracker/src/main.rs

@@ -17,6 +17,6 @@ libc = "0.2.147"
 nix = { version = "0.26.2", default-features = false, features = ["dir"] }
 regex = { version = "1.9.1", default-features = false, features = ["std"] }
 thiserror = "1.0.43"
-tracing = { version = "0.1.37", features = ["attributes"] }
+tracing = { git = "https://github.com/tokio-rs/tracing", rev = "27f688efb72316a26f3ec1f952c82626692c08ff", features = ["attributes"] }
 
 utils = { path = "../utils" }

src/jailer/Cargo.toml

@@ -16,5 +16,5 @@ serde = { version = "1.0.136", features = ["derive", "rc"] }
 serde_json = "1.0.78"
 thiserror = "1.0.32"
 vm-superio = "0.7.0"
-tracing = { version = "0.1.37", features = ["attributes"] }
+tracing = { git = "https://github.com/tokio-rs/tracing", rev = "27f688efb72316a26f3ec1f952c82626692c08ff", features = ["attributes"] }
 utils = { path = "../utils" }