logging: replacing syslog with new logger

For now, the functionality is not available through API commands.
User can specify a file on disk (--log-file) for logging messages.
Otherwise, all messages will be flushed to either stdout or stderr.

Signed-off-by: Diana Popa <[email protected]>

Author: dianpopa

Cargo.toml

@@ -11,5 +11,6 @@ devices = { path = "devices" }
 net_util = { path = "net_util" }
 sys_util = { path = "sys_util" }
 vmm = { path = "vmm" }
+logger = { path = "logger" }
 
 [workspace]

devices/Cargo.toml

@@ -14,6 +14,7 @@ sys_util = { path = "../sys_util" }
 virtio_sys = { path = "../virtio_sys" }
 vhost_sys = { path = "../vhost_sys" }
 vhost_backend = { path = "../vhost_backend" }
+logger = {path = "../logger"}
 
 [dev-dependencies]
 data_model = { path = "../data_model"}

devices/src/lib.rs

@@ -3,14 +3,13 @@
 // found in the LICENSE file.
 
 //! Emulates virtual and hardware devices.
-
 extern crate byteorder;
 extern crate epoll;
 extern crate libc;
-
+#[macro_use]
+extern crate logger;
 extern crate net_sys;
 extern crate net_util;
-#[macro_use]
 extern crate sys_util;
 extern crate vhost_backend;
 extern crate vhost_sys;

logger/src/lib.rs

@@ -21,15 +21,16 @@
 //!     error!("this is a error");
 //! }
 //! ```
-// workaround to marco_reexport
+// workaround to macro_reexport
 extern crate log;
 pub use log::*;
+pub use log::Level::*;
 
 mod error;
 mod writers;
 
 use error::LoggerError;
-use log::{set_boxed_logger, set_max_level, Level, Log, Metadata, Record};
+use log::{set_boxed_logger, set_max_level, Log, Metadata, Record};
 use std::result;
 use std::sync::{Arc, Once, ONCE_INIT};
 use writers::*;

src/main.rs

@@ -3,6 +3,7 @@ extern crate clap;
 
 extern crate api_server;
 extern crate devices;
+extern crate logger;
 extern crate net_util;
 extern crate sys_util;
 extern crate vmm;
@@ -18,19 +19,15 @@ use api_server::{ApiRequest, ApiServer};
 use api_server::request::instance_info::{InstanceInfo, InstanceState};
 use api_server::request::sync::{DeviceState, NetworkInterfaceBody, VsockJsonBody};
 use net_util::MacAddr;
-use sys_util::{syslog, EventFd, GuestAddress};
+use sys_util::{EventFd, GuestAddress};
+use logger::Logger;
 use vmm::{CMDLINE_MAX_SIZE, CMDLINE_OFFSET, KERNEL_START_OFFSET};
 use vmm::{kernel_cmdline, KernelConfig};
 use vmm::device_config::BlockDeviceConfig;
 
 const DEFAULT_SUBNET_MASK: &str = "255.255.255.0";
 
 fn main() {
-    if let Err(e) = syslog::init() {
-        println!("failed to initialize syslog: {:?}", e);
-        return;
-    }
-
     let cmd_arguments = App::new("firecracker")
         .version(crate_version!())
         .author(crate_authors!())
@@ -111,6 +108,13 @@ fn main() {
                         .long("guest-mac")
                         .help("The MAC address of the guest network interface.")
                         .takes_value(true),
+                )
+                .arg(
+                    Arg::with_name("log_file")
+                        .short("l")
+                        .long("log-file")
+                        .help("File to serve as logging output")
+                        .takes_value(true),
                 ),
         )
         .get_matches();
@@ -158,6 +162,27 @@ fn vmm_no_api_handler(
         from_api,
     ).expect("cannot create VMM");
 
+    // this is temporary; user will be able to customize logging subsystem through API
+    if cmd_arguments.is_present("log_file") {
+        if let Err(e) = Logger::new()
+            .set_level(logger::Level::Info)
+            .init(Some(String::from(
+                cmd_arguments.value_of("log_file").unwrap(),
+            ))) {
+            eprintln!(
+                "main: Failed to initialize logging subsystem: {:?}. Trying without a file",
+                e
+            );
+            if let Err(e) = Logger::new().set_level(logger::Level::Info).init(None) {
+                panic!("main: Failed to initialize logging subsystem: {:?}", e);
+            }
+        }
+    } else {
+        if let Err(e) = Logger::new().set_level(logger::Level::Info).init(None) {
+            panic!("main: Failed to initialize logging subsystem: {:?}", e);
+        }
+    }
+
     // configure virtual machine from command line
     if cmd_arguments.is_present("vcpu_count") {
         match cmd_arguments

sys_util/src/lib.rs

@@ -10,8 +10,7 @@ extern crate syscall_defines;
 
 #[macro_use]
 pub mod ioctl;
-#[macro_use]
-pub mod syslog;
+
 mod mmap;
 mod eventfd;
 mod errno;

vmm/Cargo.toml

@@ -13,6 +13,7 @@ devices = { path = "../devices" }
 kernel_loader = { path = "../kernel_loader" }
 kvm = { path = "../kvm" }
 kvm_sys = { path = "../kvm_sys" }
+logger = { path = "../logger" }
 net_util = { path = "../net_util"}
 sys_util = { path = "../sys_util" }
 x86_64 = { path = "../x86_64" }

vmm/src/lib.rs

@@ -6,8 +6,9 @@ extern crate devices;
 extern crate kernel_loader;
 extern crate kvm;
 extern crate kvm_sys;
-extern crate net_util;
 #[macro_use]
+extern crate logger;
+extern crate net_util;
 extern crate sys_util;
 extern crate x86_64;