kata-ctl: Switch to slog logging; add --log-level, --json-logging args

Fixes: #5401, #6654

- Switch kata-ctl from eprintln!()/println!() to structured logging via
  the logging library which uses slog.
- Adds a new create_term_logger() library call which enables printing
  log messages to the terminal via a less verbose / more human readable
  terminal format with colors.
- Adds --log-level argument to select the minimum log level of printed messages.
- Adds --json-logging argument to switch to logging in JSON format.

Co-authored-by: Byron Marohn <byron.marohn@intel.com>
Co-authored-by: Luke Phillips <lucas.phillips@intel.com>
Signed-off-by: Jayant Singh <jayant.singh@intel.com>
Signed-off-by: Byron Marohn <byron.marohn@intel.com>
Signed-off-by: Luke Phillips <lucas.phillips@intel.com>
Signed-off-by: Kelby Madal-Hellmuth <kelby.madal-hellmuth@intel.com>
Signed-off-by: Liz Lawrens <liz.lawrens@intel.com>

src/agent/Cargo.lock

@@ -422,6 +422,16 @@ dependencies = [
  "dirs-sys",
 ]
 
+[[package]]
+name = "dirs-next"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b98cf8ebf19c3d1b223e151f99a4f9f0690dca41414773390fc824184ac833e1"
+dependencies = [
+ "cfg-if 1.0.0",
+ "dirs-sys-next",
+]
+
 [[package]]
 name = "dirs-sys"
 version = "0.3.7"
@@ -433,6 +443,17 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "dirs-sys-next"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ebda144c4fe02d1f7ea1a7d9641b6fc6b580adcfa024ae48797ecdeb6825b4d"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi",
+]
+
 [[package]]
 name = "either"
 version = "1.6.1"
@@ -949,6 +970,7 @@ dependencies = [
  "slog-async",
  "slog-json",
  "slog-scope",
+ "slog-term",
 ]
 
 [[package]]
@@ -1762,6 +1784,12 @@ dependencies = [
  "zbus",
 ]
 
+[[package]]
+name = "rustversion"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4f3208ce4d8448b3f3e7d168a73f5e0c43a61e32930de3bceeccedb388b6bf06"
+
 [[package]]
 name = "ryu"
 version = "1.0.10"
@@ -1951,6 +1979,19 @@ dependencies = [
  "slog-scope",
 ]
 
+[[package]]
+name = "slog-term"
+version = "2.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87d29185c55b7b258b4f120eab00f48557d4d9bc814f41713f449d35b0f8977c"
+dependencies = [
+ "atty",
+ "slog",
+ "term",
+ "thread_local",
+ "time 0.3.11",
+]
+
 [[package]]
 name = "smallvec"
 version = "1.8.0"
@@ -2031,6 +2072,17 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "term"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c59df8ac95d96ff9bede18eb7300b0fda5e5d8d90960e76f8e14ae765eedbf1f"
+dependencies = [
+ "dirs-next",
+ "rustversion",
+ "winapi",
+]
+
 [[package]]
 name = "termcolor"
 version = "1.1.3"
@@ -2102,8 +2154,15 @@ dependencies = [
  "itoa",
  "libc",
  "num_threads",
+ "time-macros",
 ]
 
+[[package]]
+name = "time-macros"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42657b1a6f4d817cda8e7a0ace261fe0cc946cf3a80314390b22cc61ae080792"
+
 [[package]]
 name = "tokio"
 version = "1.28.1"

src/libs/logging/Cargo.toml

@@ -15,6 +15,7 @@ serde_json = "1.0.73"
 #   (by stopping the compiler from removing log calls).
 slog = { version = "2.5.2", features = ["dynamic-keys", "max_level_trace", "release_max_level_debug"] }
 slog-json = "2.4.0"
+slog-term = "2.9.0"
 slog-async = "2.7.0"
 slog-scope = "4.4.0"
 

src/libs/logging/src/lib.rs

@@ -39,6 +39,28 @@ const LOG_LEVELS: &[(&str, slog::Level)] = &[
 
 const DEFAULT_SUBSYSTEM: &str = "root";
 
+// Creates a logger which prints output as human readable text to the terminal
+pub fn create_term_logger(level: slog::Level) -> (slog::Logger, slog_async::AsyncGuard) {
+    let term_drain = slog_term::term_compact().fuse();
+
+    // Ensure only a unique set of key/value fields is logged
+    let unique_drain = UniqueDrain::new(term_drain).fuse();
+
+    // Allow runtime filtering of records by log level
+    let filter_drain = RuntimeLevelFilter::new(unique_drain, level).fuse();
+
+    // Ensure the logger is thread-safe
+    let (async_drain, guard) = slog_async::Async::new(filter_drain)
+        .thread_name("slog-async-logger".into())
+        .build_with_guard();
+
+    // Add some "standard" fields
+    let logger = slog::Logger::root(async_drain.fuse(), o!("subsystem" => DEFAULT_SUBSYSTEM));
+
+    (logger, guard)
+}
+
+// Creates a logger which prints output as JSON
 // XXX: 'writer' param used to make testing possible.
 pub fn create_logger<W>(
     name: &str,

src/tools/kata-ctl/Cargo.lock

@@ -96,6 +96,17 @@ dependencies = [
  "syn 1.0.107",
 ]
 
+[[package]]
+name = "atty"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
+dependencies = [
+ "hermit-abi 0.1.19",
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -280,6 +291,27 @@ dependencies = [
  "syn 1.0.107",
 ]
 
+[[package]]
+name = "dirs-next"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b98cf8ebf19c3d1b223e151f99a4f9f0690dca41414773390fc824184ac833e1"
+dependencies = [
+ "cfg-if",
+ "dirs-sys-next",
+]
+
+[[package]]
+name = "dirs-sys-next"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ebda144c4fe02d1f7ea1a7d9641b6fc6b580adcfa024ae48797ecdeb6825b4d"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi",
+]
+
 [[package]]
 name = "either"
 version = "1.8.1"
@@ -460,6 +492,17 @@ dependencies = [
  "slab",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c85e1d9ab2eadba7e5040d4e09cbd6d072b76a557ad64e797c2cb9d4da21d7e4"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
 [[package]]
 name = "glob"
 version = "0.3.1"
@@ -506,6 +549,15 @@ version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
 
+[[package]]
+name = "hermit-abi"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "hermit-abi"
 version = "0.2.6"
@@ -728,6 +780,7 @@ dependencies = [
  "hyper",
  "kata-types",
  "libc",
+ "logging",
  "micro_http",
  "nix 0.25.1",
  "privdrop",
@@ -821,6 +874,7 @@ dependencies = [
  "slog-async",
  "slog-json",
  "slog-scope",
+ "slog-term",
 ]
 
 [[package]]
@@ -961,6 +1015,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "num_threads"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2819ce041d2ee131036f4fc9d6ae7ae125a3a40e97ba64d04fe799ad9dabbb44"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "oci"
 version = "0.1.0"
@@ -1284,6 +1347,17 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "redox_users"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b033d837a7cf162d7993aded9304e30a83213c648b6e389db233191f891e5c2b"
+dependencies = [
+ "getrandom",
+ "redox_syscall",
+ "thiserror",
+]
+
 [[package]]
 name = "regex"
 version = "1.7.1"
@@ -1600,6 +1674,19 @@ dependencies = [
  "slog",
 ]
 
+[[package]]
+name = "slog-term"
+version = "2.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87d29185c55b7b258b4f120eab00f48557d4d9bc814f41713f449d35b0f8977c"
+dependencies = [
+ "atty",
+ "slog",
+ "term",
+ "thread_local",
+ "time",
+]
+
 [[package]]
 name = "smallvec"
 version = "1.10.0"
@@ -1705,6 +1792,17 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "term"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c59df8ac95d96ff9bede18eb7300b0fda5e5d8d90960e76f8e14ae765eedbf1f"
+dependencies = [
+ "dirs-next",
+ "rustversion",
+ "winapi",
+]
+
 [[package]]
 name = "test-utils"
 version = "0.1.0"
@@ -1749,6 +1847,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a561bf4617eebd33bca6434b988f39ed798e527f51a1e797d0ee4f61c0a38376"
 dependencies = [
  "itoa",
+ "libc",
+ "num_threads",
  "serde",
  "time-core",
  "time-macros",

src/tools/kata-ctl/Cargo.toml

@@ -36,6 +36,10 @@ serial_test = "0.5.1"
 vmm-sys-util = "0.11.0"
 epoll = "4.0.1"
 libc = "0.2.138"
+
+# Note: this crate sets the slog 'max_*' features which allows the log level
+# to be modified at runtime.
+logging = { path = "../../libs/logging" }
 slog = "2.7.0"
 slog-scope = "4.4.0"
 hyper = "0.14.20"

src/tools/kata-ctl/src/arch/aarch64/mod.rs

@@ -11,6 +11,7 @@ mod arch_specific {
     use crate::types::*;
     use crate::utils;
     use anyhow::Result;
+    use slog::{info, o, warn};
     use std::path::Path;
 
     const KVM_DEV: &str = "/dev/kvm";
@@ -19,6 +20,12 @@ mod arch_specific {
     #[allow(dead_code)]
     pub const ARCH_CPU_MODEL_FIELD: &str = "CPU architecture";
 
+    macro_rules! sl {
+        () => {
+            slog_scope::logger().new(o!("subsystem" => "aarch64"))
+        };
+    }
+
     // List of check functions
     static CHECK_LIST: &[CheckItem] = &[CheckItem {
         name: CheckType::Cpu,
@@ -28,11 +35,14 @@ mod arch_specific {
     }];
 
     pub fn check(_args: &str) -> Result<()> {
-        println!("INFO: check: aarch64");
+        info!(sl!(), "check: aarch64");
         if Path::new(KVM_DEV).exists() {
-            println!("Kata Containers can run on this host\n");
+            info!(sl!(), "Kata Containers can run on this host\n");
         } else {
-            eprintln!("WARNING: Kata Containers can't run on this host as lack of virtulization support\n");
+            warn!(
+                sl!(),
+                "Kata Containers can't run on this host as lack of virtulization support\n"
+            );
         }
 
         Ok(())

src/tools/kata-ctl/src/arch/s390x/mod.rs

@@ -13,6 +13,7 @@ mod arch_specific {
     use crate::utils;
     use anyhow::{anyhow, Result};
     use nix::unistd::Uid;
+    use slog::{info, o, warn};
     use std::collections::HashMap;
     use std::io::BufRead;
     use std::io::BufReader;
@@ -21,6 +22,12 @@ mod arch_specific {
     const CPUINFO_FEATURES_TAG: &str = "features";
     const CPU_FEATURES_REQ: &[&str] = &["sie"];
 
+    macro_rules! sl {
+        () => {
+            slog_scope::logger().new(o!("subsystem" => "s390x"))
+        };
+    }
+
     #[allow(dead_code)]
     pub const ARCH_CPU_VENDOR_FIELD: &str = check::GENERIC_CPU_VENDOR_FIELD;
     #[allow(dead_code)]
@@ -28,7 +35,7 @@ mod arch_specific {
 
     // check cpu
     fn check_cpu() -> Result<()> {
-        println!("INFO: check CPU: s390x");
+        info!(sl!(), "check CPU: s390x");
 
         let cpu_info = check::get_single_cpu_info(check::PROC_CPUINFO, CPUINFO_DELIMITER)?;
 
@@ -42,14 +49,14 @@ mod arch_specific {
 
         let missing_cpu_features = check::check_cpu_flags(&cpu_features, CPU_FEATURES_REQ)?;
         if !missing_cpu_features.is_empty() {
-            eprintln!("WARNING: Missing CPU flags {:?}", missing_cpu_features);
+            warn!(sl!(), "Missing CPU flags {:?}", missing_cpu_features);
         }
 
         Ok(())
     }
 
     pub fn check(_args: &str) -> Result<()> {
-        println!("INFO: check: s390x");
+        info!(sl!(), "check: s390x");
 
         let _cpu_result = check_cpu();
 

src/tools/kata-ctl/src/arch/x86_64/mod.rs

@@ -15,6 +15,7 @@ mod arch_specific {
     use crate::utils;
     use anyhow::{anyhow, Context, Result};
     use nix::unistd::Uid;
+    use slog::{info, o, warn};
     use std::fs;
     use std::path::Path;
 
@@ -27,6 +28,12 @@ mod arch_specific {
     pub const ARCH_CPU_VENDOR_FIELD: &str = check::GENERIC_CPU_VENDOR_FIELD;
     pub const ARCH_CPU_MODEL_FIELD: &str = check::GENERIC_CPU_MODEL_FIELD;
 
+    macro_rules! sl {
+         () => {
+             slog_scope::logger().new(o!("subsystem" => "x86_64"))
+         };
+    }
+
     // List of check functions
     static CHECK_LIST: &[CheckItem] = &[
         CheckItem {
@@ -72,7 +79,7 @@ mod arch_specific {
 
     // check cpu
     fn check_cpu(_args: &str) -> Result<()> {
-        println!("INFO: check CPU: x86_64");
+        info!(sl!(), "check CPU: x86_64");
 
         let cpu_info = check::get_single_cpu_info(check::PROC_CPUINFO, CPUINFO_DELIMITER)?;
 
@@ -89,14 +96,11 @@ mod arch_specific {
         // TODO: Add more information to output (see kata-check in go tool); adjust formatting
         let missing_cpu_attributes = check::check_cpu_attribs(&cpu_info, CPU_ATTRIBS_INTEL)?;
         if !missing_cpu_attributes.is_empty() {
-            eprintln!(
+            warn!(sl!(), "Missing CPU attributes {:?}", missing_cpu_attributes);
-                "WARNING: Missing CPU attributes {:?}",
-                missing_cpu_attributes
-            );
         }
         let missing_cpu_flags = check::check_cpu_flags(&cpu_flags, CPU_FLAGS_INTEL)?;
         if !missing_cpu_flags.is_empty() {
-            eprintln!("WARNING: Missing CPU flags {:?}", missing_cpu_flags);
+            warn!(sl!(), "Missing CPU flags {:?}", missing_cpu_flags);
         }
 
         Ok(())
@@ -122,7 +126,7 @@ mod arch_specific {
 
     // check if kvm is usable
     fn check_kvm_is_usable(_args: &str) -> Result<()> {
-        println!("INFO: check if kvm is usable: x86_64");
+        info!(sl!(), "check if kvm is usable: x86_64");
 
         let result = check::check_kvm_is_usable_generic();
 
@@ -275,7 +279,7 @@ mod arch_specific {
     }
 
     fn check_kernel_modules(_args: &str) -> Result<()> {
-        println!("INFO: check kernel modules for: x86_64");
+        info!(sl!(), "check kernel modules for: x86_64");
 
         for module in MODULE_LIST {
             let module_loaded =
@@ -291,12 +295,12 @@ mod arch_specific {
                     );
 
                     match parameter_check {
-                        Ok(_v) => println!("{} Ok", module.name),
+                        Ok(_v) => info!(sl!(), "{} Ok", module.name),
                         Err(e) => return Err(e),
                     }
                 }
                 Err(err) => {
-                    eprintln!("WARNING {:}", err.replace('\n', ""))
+                    warn!(sl!(), "{:}", err.replace('\n', ""))
                 }
             }
         }

src/tools/kata-ctl/src/args.rs

@@ -12,6 +12,25 @@ use thiserror::Error;
 pub struct KataCtlCli {
     #[clap(subcommand)]
     pub command: Commands,
+    #[clap(short, long, value_enum, value_parser = parse_log_level)]
+    /// Sets the minimum log level required for log messages to be displayed. Default is 'info'.
+    /// Valid values are: trace, debug, info, warning, error, critical
+    pub log_level: Option<slog::Level>,
+    #[clap(short, long, action)]
+    /// If enabled, log messages will be JSON formatted for easier machine parsing
+    pub json_logging: bool,
+}
+
+fn parse_log_level(arg: &str) -> Result<slog::Level, String> {
+    match arg {
+        "trace" => Ok(slog::Level::Trace),
+        "debug" => Ok(slog::Level::Debug),
+        "info" => Ok(slog::Level::Info),
+        "warning" => Ok(slog::Level::Warning),
+        "error" => Ok(slog::Level::Error),
+        "critical" => Ok(slog::Level::Critical),
+        _ => Err("Must be one of [trace, debug, info, warning, error, critical]".to_string()),
+    }
 }
 
 #[derive(Debug, Subcommand)]

src/tools/kata-ctl/src/check.rs

@@ -12,6 +12,7 @@ use nix::unistd::close;
 use nix::{ioctl_write_int_bad, request_code_none};
 use reqwest::header::{CONTENT_TYPE, USER_AGENT};
 use serde::{Deserialize, Serialize};
+use slog::{info, o};
 use std::fmt;
 use thiserror::Error;
 
@@ -51,6 +52,12 @@ pub const GENERIC_CPU_MODEL_FIELD: &str = "model name";
 #[allow(dead_code)]
 pub const PROC_CPUINFO: &str = "/proc/cpuinfo";
 
+macro_rules! sl {
+    () => {
+        slog_scope::logger().new(o!("subsystem" => "check"))
+    };
+}
+
 fn read_file_contents(file_path: &str) -> Result<String> {
     let contents = std::fs::read_to_string(file_path)?;
     Ok(contents)
@@ -276,14 +283,20 @@ pub fn check_all_releases() -> Result<()> {
 
     for release in releases {
         if !release.prerelease {
-            println!(
+            info!(
+                sl!(),
                 "Official  : Release {:15}; created {} ; {}",
-                release.tag_name, release.created_at, release.tarball_url
+                release.tag_name,
+                release.created_at,
+                release.tarball_url
             );
         } else {
-            println!(
+            info!(
+                sl!(),
                 "PreRelease: Release {:15}; created {} ; {}",
-                release.tag_name, release.created_at, release.tarball_url
+                release.tag_name,
+                release.created_at,
+                release.tarball_url
             );
         }
     }
@@ -294,12 +307,15 @@ pub fn check_official_releases() -> Result<()> {
     let releases: Vec<Release> =
         get_kata_all_releases_by_url(KATA_GITHUB_RELEASE_URL).map_err(handle_reqwest_error)?;
 
-    println!("Official Releases...");
+    info!(sl!(), "Official Releases...");
     for release in releases {
         if !release.prerelease {
-            println!(
+            info!(
+                sl!(),
                 "Release {:15}; created {} ; {}",
-                release.tag_name, release.created_at, release.tarball_url
+                release.tag_name,
+                release.created_at,
+                release.tarball_url
             );
         }
     }
@@ -392,6 +408,7 @@ pub fn check_kernel_module_loaded(module: &str, parameter: &str) -> Result<Strin
 mod tests {
     use super::*;
     use semver::Version;
+    use slog::warn;
     use std::fs;
     use std::io::Write;
     use tempfile::tempdir;
@@ -573,8 +590,9 @@ mod tests {
         // sometime in GitHub action accessing to github.com API may fail
         // we can skip this test to prevent the whole test fail.
         if releases.is_err() {
-            println!(
+            warn!(
-                "WARNING!!!\nget kata version failed({:?}), this maybe a temporary error, just skip the test.",
+                sl!(),
+                "get kata version failed({:?}), this maybe a temporary error, just skip the test.",
                 releases.unwrap_err()
             );
             return;

src/tools/kata-ctl/src/main.rs

@@ -11,7 +11,8 @@ mod types;
 mod utils;
 
 use anyhow::Result;
-use clap::Parser;
+use clap::{crate_name, Parser};
+use std::io;
 use std::process::exit;
 
 use args::{Commands, KataCtlCli};
@@ -22,11 +23,28 @@ use ops::check_ops::{
 use ops::env_ops::handle_env;
 use ops::exec_ops::handle_exec;
 use ops::volume_ops::handle_direct_volume;
+use slog::{error, o};
+
+macro_rules! sl {
+    () => {
+        slog_scope::logger().new(o!("subsystem" => "kata-ctl_main"))
+    };
+}
 
 fn real_main() -> Result<()> {
     let args = KataCtlCli::parse();
 
-    match args.command {
+    let log_level = args.log_level.unwrap_or(slog::Level::Info);
+
+    let (logger, _guard) = if args.json_logging {
+        logging::create_logger(crate_name!(), crate_name!(), log_level, io::stdout())
+    } else {
+        logging::create_term_logger(log_level)
+    };
+
+    let _guard = slog_scope::set_global_logger(logger);
+
+    let res = match args.command {
         Commands::Check(args) => handle_check(args),
         Commands::DirectVolume(args) => handle_direct_volume(args),
         Commands::Exec(args) => handle_exec(args),
@@ -35,12 +53,19 @@ fn real_main() -> Result<()> {
         Commands::Iptables(args) => handle_iptables(args),
         Commands::Metrics(args) => handle_metrics(args),
         Commands::Version => handle_version(),
+    };
+
+    // Log errors here, then let the logger go out of scope in main() to ensure
+    // the asynchronous drain flushes all messages before exit()
+    if let Err(e) = &res {
+        error!(sl!(), "{:#?}", e);
     }
+
+    res
 }
 
 fn main() {
-    if let Err(e) = real_main() {
+    if let Err(_e) = real_main() {
-        eprintln!("ERROR: {:#?}", e);
         exit(1);
     }
 }

src/tools/kata-ctl/src/ops/check_ops.rs

@@ -15,8 +15,16 @@ use crate::types::*;
 
 use anyhow::{anyhow, Result};
 
+use slog::{info, o, warn};
+
 const NAME: &str = "kata-ctl";
 
+macro_rules! sl {
+    () => {
+        slog_scope::logger().new(o!("subsystem" => "check_ops"))
+    };
+}
+
 // This function retrieves the cmd function passes as argument
 fn get_builtin_check_func(name: CheckType) -> Result<BuiltinCmdFp> {
     if let Some(check_list) = get_checks() {
@@ -55,14 +63,12 @@ fn print_check_list() -> Result<()> {
     let cmds = get_client_cmd_details();
 
     if cmds.is_empty() {
-        println!("Checks not found!\n");
+        warn!(sl!(), "Checks not found!\n");
 
         return Ok(());
     }
 
-    cmds.iter().for_each(|n| println!(" - {}", n));
+    cmds.iter().for_each(|n| info!(sl!(), " - {}", n));
-
-    println!();
 
     Ok(())
 }
@@ -125,6 +131,6 @@ pub fn handle_metrics(_args: MetricsCommand) -> Result<()> {
 pub fn handle_version() -> Result<()> {
     let version = version::get().unwrap();
 
-    println!("{} version {:?} (type: rust)", NAME, version);
+    info!(sl!(), "{} version {:?} (type: rust)", NAME, version);
     Ok(())
 }

src/tools/kata-ctl/src/ops/exec_ops.rs

@@ -19,7 +19,7 @@ use std::{
 use anyhow::{anyhow, Context};
 use nix::sys::socket::{connect, socket, AddressFamily, SockFlag, SockType, VsockAddr};
 use reqwest::StatusCode;
-use slog::debug;
+use slog::{debug, error, o};
 use vmm_sys_util::terminal::Terminal;
 
 use crate::args::ExecArguments;
@@ -40,7 +40,7 @@ type Result<T> = std::result::Result<T, Error>;
 #[macro_export]
 macro_rules! sl {
     () => {
-        slog_scope::logger()
+        slog_scope::logger().new(o!("subsystem" => "exec_ops"))
     };
 }
 
@@ -142,7 +142,7 @@ impl EpollContext {
                                 return Ok(());
                             }
                             Err(e) => {
-                                println!("error with errno {:?} while reading stdin", e);
+                                error!(sl!(), "errno {:?} while reading stdin", e);
                                 return Ok(());
                             }
                             Ok(count) => {
@@ -159,7 +159,7 @@ impl EpollContext {
                                 return Ok(());
                             }
                             Err(e) => {
-                                println!("error with errno {:?} while reading server", e);
+                                error!(sl!(), "errno {:?} while reading server", e);
                                 return Ok(());
                             }
                             Ok(count) => {

src/tools/kata-ctl/src/ops/volume_ops.rs

@@ -13,6 +13,7 @@ use kata_types::mount::{
 };
 use nix;
 use reqwest::StatusCode;
+use slog::{info, o};
 use std::{fs, time::Duration};
 use url;
 
@@ -25,6 +26,12 @@ use shim_interface::shim_mgmt::{
 const TIMEOUT: Duration = Duration::from_millis(2000);
 const CONTENT_TYPE_JSON: &str = "application/json";
 
+macro_rules! sl {
+    () => {
+        slog_scope::logger().new(o!("subsystem" => "volume_ops"))
+    };
+}
+
 pub fn handle_direct_volume(vol_cmd: DirectVolumeCommand) -> Result<()> {
     if !nix::unistd::Uid::effective().is_root() {
         return Err(anyhow!(
@@ -41,7 +48,7 @@ pub fn handle_direct_volume(vol_cmd: DirectVolumeCommand) -> Result<()> {
         }
     };
     if let Some(cmd_result) = cmd_result {
-        println!("{:?}", cmd_result);
+        info!(sl!(), "{:?}", cmd_result);
     }
 
     Ok(())