Allow multiple log drivers to be specified

This extends the API to allow multiple log drivers in parallel. We can later on support other drivers like files to log into multiple destinations. Signed-off-by: Sascha Grunert <[email protected]>
containers · Oct 4, 2022 · 39bdb3f · 39bdb3f
1 parent e58ae5a
commit 39bdb3f
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Showing 3 changed files with 50 additions and 37 deletions.
diff --git a/conmon-rs/server/src/config.rs b/conmon-rs/server/src/config.rs
@@ -48,17 +48,18 @@ pub struct Config {
     /// The logging level of the conmon server.
     log_level: String,
 
-    #[get_copy = "pub"]
+    #[get = "pub"]
     #[clap(
         default_value(LogDriver::Systemd.into()),
-        env(concat!(prefix!(), "LOG_DRIVER")),
-        long("log-driver"),
+        env(concat!(prefix!(), "LOG_DRIVERS")),
+        multiple(true),
+        long("log-drivers"),
         short('d'),
         possible_values(LogDriver::iter().map(|x| x.into()).collect::<Vec<&str>>()),
-        value_name("DRIVER")
+        value_name("DRIVERS")
     )]
-    /// The logging driver used by the conmon server.
-    log_driver: LogDriver,
+    /// The logging drivers used by the server. Can be specified multiple times.
+    log_drivers: Vec<LogDriver>,
 
     #[get = "pub"]
     #[clap(

diff --git a/conmon-rs/server/src/server.rs b/conmon-rs/server/src/server.rs
@@ -108,30 +108,32 @@ impl Server {
             LevelFilter::from_str(self.config().log_level()).context("convert log level filter")?;
         let registry = tracing_subscriber::registry();
 
-        match self.config().log_driver() {
-            LogDriver::Stdout => {
-                let layer = tracing_subscriber::fmt::layer()
-                    .with_target(true)
-                    .with_line_number(true)
-                    .with_filter(level);
-                registry
-                    .with(layer)
-                    .try_init()
-                    .context("init stdout fmt layer")?;
-                info!("Using stdout logger");
-            }
-            LogDriver::Systemd => {
-                let layer = tracing_journald::layer()
-                    .context("unable to connect to journald")?
-                    .with_filter(level);
-                registry
-                    .with(layer)
-                    .try_init()
-                    .context("init journald layer")?;
-                info!("Using systemd/journald logger");
-            }
-        }
+        let stdout = if self.config().log_drivers().contains(&LogDriver::Stdout) {
+            tracing_subscriber::fmt::layer()
+                .with_target(true)
+                .with_line_number(true)
+                .with_filter(level)
+                .into()
+        } else {
+            None
+        };
+
+        let systemd = if self.config().log_drivers().contains(&LogDriver::Systemd) {
+            tracing_journald::layer()
+                .context("unable to connect to journald")?
+                .with_filter(level)
+                .into()
+        } else {
+            None
+        };
+
+        registry
+            .with(stdout)
+            .with(systemd)
+            .try_init()
+            .context("init registry")?;
         info!("Set log level to: {}", self.config().log_level());
+
         Ok(())
     }
 

diff --git a/pkg/client/client.go b/pkg/client/client.go
@@ -57,9 +57,9 @@ type ConmonServerConfig struct {
 	// Can be "trace", "debug", "info", "warn", "error" or "off".
 	LogLevel string
 
-	// LogDriver is the possible server logging driver.
-	// Can be "stdout" or "systemd".
-	LogDriver string
+	// LogDrivers are the possible server logging drivers.
+	// Can be "stdout", "systemd" or both.
+	LogDrivers []string
 
 	// Runtime is the binary path of the OCI runtime to use to operate on the
 	// containers.
@@ -106,7 +106,7 @@ func NewConmonServerConfig(
 ) *ConmonServerConfig {
 	return &ConmonServerConfig{
 		LogLevel:     LogLevelDebug,
-		LogDriver:    LogDriverStdout,
+		LogDrivers:   []string{LogDriverStdout},
 		Runtime:      runtime,
 		RuntimeRoot:  runtimeRoot,
 		ServerRunDir: serverRunDir,
@@ -212,7 +212,7 @@ func (c *ConmonClient) startServer(config *ConmonServerConfig) error {
 		Setpgid: true,
 	}
 
-	if config.LogDriver == LogDriverStdout {
+	if contains(config.LogDrivers, LogDriverStdout) {
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
 		if config.Stdout != nil {
@@ -230,6 +230,16 @@ func (c *ConmonClient) startServer(config *ConmonServerConfig) error {
 	return nil
 }
 
+func contains[T comparable](haystack []T, needle T) bool {
+	for _, value := range haystack {
+		if value == needle {
+			return true
+		}
+	}
+
+	return false
+}
+
 func (c *ConmonClient) toArgs(config *ConmonServerConfig) (entrypoint string, args []string, err error) {
 	if c == nil {
 		return "", args, nil
@@ -263,11 +273,11 @@ func (c *ConmonClient) toArgs(config *ConmonServerConfig) (entrypoint string, ar
 		args = append(args, "--log-level", config.LogLevel)
 	}
 
-	if config.LogDriver != "" {
-		if err := validateLogDriver(config.LogDriver); err != nil {
+	for _, driver := range config.LogDrivers {
+		if err := validateLogDriver(driver); err != nil {
 			return "", args, fmt.Errorf("validate log driver: %w", err)
 		}
-		args = append(args, "--log-driver", config.LogDriver)
+		args = append(args, "--log-drivers", driver)
 	}
 
 	const cgroupManagerFlag = "--cgroup-manager"