Merge pull request 'Add support to logging to syslog (based on patch by @jirutka)' (#784) from syslog into main

Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/784

8 files changed, 111 insertions, 13 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 2b2111c9..b4cf5bd0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1322,6 +1322,7 @@ dependencies = [
  "sha2",
  "static_init",
  "structopt",
+ "syslog-tracing",
  "timeago",
  "tokio",
  "toml",
@@ -3931,6 +3932,17 @@ dependencies = [
 ]
 
 [[package]]
+name = "syslog-tracing"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "340b1540dcdb6b066bc2966e7974f977ab1a38f21b2be189014ffb0cc2405768"
+dependencies = [
+ "libc",
+ "tracing-core",
+ "tracing-subscriber",
+]
+
+[[package]]
 name = "system-configuration"
 version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.nix b/Cargo.nix
index 852e96bf..44cb23b5 100644
--- a/Cargo.nix
+++ b/Cargo.nix
@@ -34,7 +34,7 @@ args@{
   ignoreLockHash,
 }:
 let
-  nixifiedLockHash = "b35dd31aa882ac6fc7105fb99a6681a4777ed269191cb0a8c8db843910748435";
+  nixifiedLockHash = "1d6c837fe8357cbb1b231c1843bde1729c9864f05e5ae251be045450a0b592e3";
   workspaceSrc = if args.workspaceSrc == null then ./. else args.workspaceSrc;
   currentLockHash = builtins.hashFile "sha256" (workspaceSrc + /Cargo.lock);
   lockHashIgnored = if ignoreLockHash
@@ -1889,6 +1889,8 @@ in
       (lib.optional (rootFeatures' ? "garage/default" || rootFeatures' ? "garage/metrics" || rootFeatures' ? "garage/prometheus") "prometheus")
       (lib.optional (rootFeatures' ? "garage/default" || rootFeatures' ? "garage/sled") "sled")
       (lib.optional (rootFeatures' ? "garage/default" || rootFeatures' ? "garage/sqlite") "sqlite")
+      (lib.optional (rootFeatures' ? "garage/syslog") "syslog")
+      (lib.optional (rootFeatures' ? "garage/syslog" || rootFeatures' ? "garage/syslog-tracing") "syslog-tracing")
       (lib.optional (rootFeatures' ? "garage/system-libs") "system-libs")
       (lib.optional (rootFeatures' ? "garage/telemetry-otlp") "telemetry-otlp")
     ];
@@ -1921,6 +1923,7 @@ in
       serde = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde."1.0.196" { inherit profileName; }).out;
       serde_bytes = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".serde_bytes."0.11.14" { inherit profileName; }).out;
       structopt = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".structopt."0.3.26" { inherit profileName; }).out;
+      ${ if rootFeatures' ? "garage/syslog" || rootFeatures' ? "garage/syslog-tracing" then "syslog_tracing" else null } = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".syslog-tracing."0.3.0" { inherit profileName; }).out;
       timeago = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".timeago."0.4.2" { inherit profileName; }).out;
       tokio = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".tokio."1.36.0" { inherit profileName; }).out;
       toml = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".toml."0.8.10" { inherit profileName; }).out;
@@ -5612,6 +5615,18 @@ in
     };
   });
   
+  "registry+https://github.com/rust-lang/crates.io-index".syslog-tracing."0.3.0" = overridableMkRustCrate (profileName: rec {
+    name = "syslog-tracing";
+    version = "0.3.0";
+    registry = "registry+https://github.com/rust-lang/crates.io-index";
+    src = fetchCratesIo { inherit name version; sha256 = "340b1540dcdb6b066bc2966e7974f977ab1a38f21b2be189014ffb0cc2405768"; };
+    dependencies = {
+      ${ if rootFeatures' ? "garage/syslog" || rootFeatures' ? "garage/syslog-tracing" then "libc" else null } = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".libc."0.2.153" { inherit profileName; }).out;
+      ${ if rootFeatures' ? "garage/syslog" || rootFeatures' ? "garage/syslog-tracing" then "tracing_core" else null } = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".tracing-core."0.1.32" { inherit profileName; }).out;
+      ${ if rootFeatures' ? "garage/syslog" || rootFeatures' ? "garage/syslog-tracing" then "tracing_subscriber" else null } = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".tracing-subscriber."0.3.18" { inherit profileName; }).out;
+    };
+  });
+  
   "registry+https://github.com/rust-lang/crates.io-index".system-configuration."0.5.1" = overridableMkRustCrate (profileName: rec {
     name = "system-configuration";
     version = "0.5.1";
diff --git a/Cargo.toml b/Cargo.toml
index c6f6f963..d3bbb301 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -72,6 +72,7 @@ kuska-handshake = { version = "0.2.0", features = ["default", "async_std"] }
 clap = { version = "4.1", features = ["derive", "env"] }
 pretty_env_logger = "0.5"
 structopt = { version = "0.3", default-features = false }
+syslog-tracing = "0.3"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 
diff --git a/doc/book/cookbook/from-source.md b/doc/book/cookbook/from-source.md
index ade47e96..0d7d8e77 100644
--- a/doc/book/cookbook/from-source.md
+++ b/doc/book/cookbook/from-source.md
@@ -90,6 +90,7 @@ The following feature flags are available in v0.8.0:
 | `kubernetes-discovery` | optional | Enable automatic registration and discovery<br>of cluster nodes through the Kubernetes API |
 | `metrics` | *by default* | Enable collection of metrics in Prometheus format on the admin API |
 | `telemetry-otlp` | optional | Enable collection of execution traces using OpenTelemetry |
+| `syslog` | optional | Enable logging to Syslog |
 | `sled` | *by default* | Enable using Sled to store Garage's metadata |
 | `lmdb` | *by default* | Enable using LMDB to store Garage's metadata |
 | `sqlite` | *by default* | Enable using Sqlite3 to store Garage's metadata |
diff --git a/doc/book/reference-manual/configuration.md b/doc/book/reference-manual/configuration.md
index de800ec0..e6aced6d 100644
--- a/doc/book/reference-manual/configuration.md
+++ b/doc/book/reference-manual/configuration.md
@@ -32,6 +32,8 @@ rpc_bind_addr = "[::]:3901"
 rpc_bind_outgoing = false
 rpc_public_addr = "[fc00:1::1]:3901"
 
+allow_world_readable_secrets = false
+
 bootstrap_peers = [
     "563e1ac825ee3323aa441e72c26d1030d6d4414aeb3dd25287c531e7fc2bc95d@[fc00:1::1]:3901",
     "86f0f26ae4afbd59aaf9cfb059eefac844951efd5b8caeec0d53f4ed6c85f332@[fc00:1::2]:3901",
@@ -82,7 +84,10 @@ The following gives details about each available configuration option.
 
 ### Index
 
+[Environment variables](#env_variables).
+
 Top-level configuration options:
+[`allow_world_readable_secrets`](#allow_world_readable_secrets),
 [`block_size`](#block_size),
 [`bootstrap_peers`](#bootstrap_peers),
 [`compression_level`](#compression_level),
@@ -134,6 +139,23 @@ The `[admin]` section:
 [`admin_token`/`admin_token_file`](#admin_token),
 [`trace_sink`](#admin_trace_sink),
 
+### Environment variables {#env_variables}
+
+The following configuration parameter must be specified as an environment
+variable, it does not exist in the configuration file:
+
+- `GARAGE_LOG_TO_SYSLOG` (since v0.9.4): set this to `1` or `true` to make the
+  Garage daemon send its logs to `syslog` (using the libc `syslog` function)
+  instead of printing to stderr.
+
+The following environment variables can be used to override the corresponding
+values in the configuration file:
+
+- [`GARAGE_ALLOW_WORLD_READABLE_SECRETS`](#allow_world_readable_secrets)
+- [`GARAGE_RPC_SECRET` and `GARAGE_RPC_SECRET_FILE`](#rpc_secret)
+- [`GARAGE_ADMIN_TOKEN` and `GARAGE_ADMIN_TOKEN_FILE`](#admin_token)
+- [`GARAGE_METRICS_TOKEN` and `GARAGE_METRICS_TOKEN`](#admin_metrics_token)
+
 
 ### Top-level configuration options
 
@@ -503,7 +525,7 @@ be obtained by running `garage node id` and then included directly in the
 key will be returned by `garage node id` and you will have to add the IP
 yourself.
 
-### `allow_world_readable_secrets`
+### `allow_world_readable_secrets` or `GARAGE_ALLOW_WORLD_READABLE_SECRETS` (env) {#allow_world_readable_secrets}
 
 Garage checks the permissions of your secret files to make sure they're not
 world-readable. In some cases, the check might fail and consider your files as
diff --git a/nix/compile.nix b/nix/compile.nix
index b276495d..fdb427f2 100644
--- a/nix/compile.nix
+++ b/nix/compile.nix
@@ -173,6 +173,7 @@ let
       "garage/kubernetes-discovery"
       "garage/metrics"
       "garage/telemetry-otlp"
+      "garage/syslog"
     ] else
       [ ]));
 
diff --git a/src/garage/Cargo.toml b/src/garage/Cargo.toml
index b022049c..52861853 100644
--- a/src/garage/Cargo.toml
+++ b/src/garage/Cargo.toml
@@ -58,6 +58,7 @@ opentelemetry.workspace = true
 opentelemetry-prometheus = { workspace = true, optional = true }
 opentelemetry-otlp = { workspace = true, optional = true }
 prometheus = { workspace = true, optional = true }
+syslog-tracing = { workspace = true, optional = true }
 
 [dev-dependencies]
 aws-config.workspace = true
@@ -97,6 +98,8 @@ kubernetes-discovery = [ "garage_rpc/kubernetes-discovery" ]
 metrics = [ "garage_api/metrics", "opentelemetry-prometheus", "prometheus" ]
 # Exporter for the OpenTelemetry Collector.
 telemetry-otlp = [ "opentelemetry-otlp" ]
+# Logging to syslog
+syslog = [ "syslog-tracing" ]
 
 # NOTE: bundled-libs and system-libs should be treat as mutually exclusive;
 # exactly one of them should be enabled.
diff --git a/src/garage/main.rs b/src/garage/main.rs
index e489fff0..2f9ae508 100644
--- a/src/garage/main.rs
+++ b/src/garage/main.rs
@@ -140,17 +140,8 @@ async fn main() {
 	let opt = Opt::from_clap(&Opt::clap().version(version.as_str()).get_matches());
 
 	// Initialize logging as well as other libraries used in Garage
-	if std::env::var("RUST_LOG").is_err() {
-		let default_log = match &opt.cmd {
-			Command::Server => "netapp=info,garage=info",
-			_ => "netapp=warn,garage=warn",
-		};
-		std::env::set_var("RUST_LOG", default_log)
-	}
-	tracing_subscriber::fmt()
-		.with_writer(std::io::stderr)
-		.with_env_filter(tracing_subscriber::filter::EnvFilter::from_default_env())
-		.init();
+	init_logging(&opt);
+
 	sodiumoxide::init().expect("Unable to init sodiumoxide");
 
 	let res = match opt.cmd {
@@ -173,6 +164,58 @@ async fn main() {
 	}
 }
 
+fn init_logging(opt: &Opt) {
+	if std::env::var("RUST_LOG").is_err() {
+		let default_log = match &opt.cmd {
+			Command::Server => "netapp=info,garage=info",
+			_ => "netapp=warn,garage=warn",
+		};
+		std::env::set_var("RUST_LOG", default_log)
+	}
+
+	let env_filter = tracing_subscriber::filter::EnvFilter::from_default_env();
+
+	if std::env::var("GARAGE_LOG_TO_SYSLOG")
+		.map(|x| x == "1" || x == "true")
+		.unwrap_or(false)
+	{
+		#[cfg(feature = "syslog")]
+		{
+			use std::ffi::CStr;
+			use syslog_tracing::{Facility, Options, Syslog};
+
+			let syslog = Syslog::new(
+				CStr::from_bytes_with_nul(b"garage\0").unwrap(),
+				Options::LOG_PID | Options::LOG_PERROR,
+				Facility::Daemon,
+			)
+			.expect("Unable to init syslog");
+
+			tracing_subscriber::fmt()
+				.with_writer(syslog)
+				.with_env_filter(env_filter)
+				.with_ansi(false) // disable ANSI escape sequences (colours)
+				.with_file(false)
+				.with_level(false)
+				.without_time()
+				.compact()
+				.init();
+
+			return;
+		}
+		#[cfg(not(feature = "syslog"))]
+		{
+			eprintln!("Syslog support is not enabled in this build.");
+			std::process::exit(1);
+		}
+	}
+
+	tracing_subscriber::fmt()
+		.with_writer(std::io::stderr)
+		.with_env_filter(env_filter)
+		.init();
+}
+
 async fn cli_command(opt: Opt) -> Result<(), Error> {
 	let config = if (opt.secrets.rpc_secret.is_none() && opt.secrets.rpc_secret_file.is_none())
 		|| opt.rpc_host.is_none()