Add the optional status configuration for health checks and other info

See #7

Cargo.toml

@@ -8,33 +8,40 @@ edition = "2018"
 
 [dependencies]
 # Base asynchronous runtime
-async-std = "~1.5.0"
+async-std = { version = "~1.6.0", features = ["attributes"] }
+async-trait = "0.1.31"
 futures = { version = "~0.3.4", features = ["thread-pool"] }
 
-# For parsing the syslog formatted messages
-syslog_rfc5424 = "~0.6.1"
-syslog_loose = "0.2.0"
-
 # Needed for listening for TLS connections
 async-tls = "~0.7.0"
 rustls = "~0.17.0"
 
+# Handling command line options
+clap = { version = "~2.33.0", features = ["yaml"] }
+# Needed for time management
+chrono = "~0.4.11"
+# Handling configuration overlays
+config = { version = "~0.10.1", features = ["yaml"] }
 # Requiredfor communciating with across internal queues
 crossbeam = "~0.7"
+# Needed to report metrics of hotdog's performance
+dipstick = "~0.8.0"
+# Used for string replacements and other template based transformations
+handlebars = "~3.0.1"
+# used for rule matching on JSON
+#  The "sync" feature is undocumented but required in order to swap Rc for Arc
+#  in the crate, allowing it to be used with futures and threads properly
+jmespath = { git = "https://github.com/jmespath/jmespath.rs", features = ["sync"] }
+# Logging
+log = "~0.4.8"
+pretty_env_logger = "~0.3.1"
 
 # Needed for forwarding messages along to Kafka
 # including the SSL and SASL features to ensure that this can authenticate
 # against secure Kafka clusters, e.g. AWS MSK
 rdkafka = { version = "~0.23.1", features = ["ssl", "sasl"]}
-
-# Handling command line options
-clap = { version = "~2.33.0", features = ["yaml"] }
-# Handling configuration overlays
-config = { version = "~0.10.1", features = ["yaml"] }
-
-# Logging
-log = "~0.4.8"
-pretty_env_logger = "~0.3.1"
+# Used for rule matching
+regex = "~1.3.6"
 
 # Needed for deserializing JSON messages _and_ managing our configuration
 # effectively
@@ -44,29 +51,20 @@ serde_json = "~1.0.0"
 # Helpful to deserialize our regular expressions directly from the
 # configuration file
 serde_regex = "~0.4.0"
+# Needed to do clever enum/derive tricks for strings
+strum = "0.18.0"
+strum_macros = "0.18.0"
 
-# Used for rule matching
-regex = "~1.3.6"
+# For parsing the syslog formatted messages
+syslog_rfc5424 = "~0.6.1"
+syslog_loose = "0.2.0"
 
-# used for rule matching on JSON
-#  The "sync" feature is undocumented but required in order to swap Rc for Arc
-#  in the crate, allowing it to be used with futures and threads properly
-jmespath = { git = "https://github.com/jmespath/jmespath.rs", features = ["sync"] }
-
-# Needed to report metrics of hotdog's performance
-dipstick = "~0.8.0"
-
-# Used for string replacements and other template based transformations
-handlebars = "~3.0.1"
-
-# Needed for time management
-chrono = "~0.4.11"
+# Needed for the http-based health checks
+tide = "~0.9.0"
 
 # Needed to tag rules and actions with their own unique identifiers
 uuid = { version = "~0.8.1", features = ["v4"] }
 
-async-trait = "0.1.31"
-
 
 # Optimize the heck out of the release build, I have no idea what these flags
 # do

README.adoc

@@ -221,6 +221,23 @@ global:
 ----
 
 
+[[yml-status]]
+==== Status
+
+The `global.status` configuration is fully _optional_ but when it is enabled `hotdog`
+will spin up an HTTP server on the configured `address` and `port` in order to provide
+real-time status information about the daemon's runtime to HTTP clients.
+
+
+.hotdog.yml
+[source,yaml]
+----
+global:
+  status:
+    address: 'localhost'
+    port: 8585
+----
+
 [[rules]]
 === Rules
 

hotdog.yml

@@ -9,7 +9,9 @@ global:
       key: './contrib/cert-key.pem'
     # Swap these values out in order to listen for plaintext syslog
     #port: 1514
-    #tls:
+  status:
+    address: '127.0.0.1'
+    port: 8585
   kafka:
     # Maximum number of messages to buffer internally while waiting for Kafka
     # responses

src/main.rs

@@ -15,6 +15,9 @@ extern crate serde_derive;
 extern crate serde_regex;
 extern crate syslog_loose;
 extern crate syslog_rfc5424;
+extern crate strum;
+#[macro_use]
+extern crate strum_macros;
 
 use async_std::{sync::Arc, task};
 use clap::{App, Arg};
@@ -31,6 +34,7 @@ mod serve;
 mod serve_plain;
 mod serve_tls;
 mod settings;
+mod status;
 
 use serve::*;
 use settings::*;
@@ -64,6 +68,15 @@ fn main() -> Result<(), errors::HotdogError> {
     let settings_file = matches.value_of("config").unwrap_or("hotdog.yml");
     let settings = Arc::new(settings::load(settings_file));
 
+    if let Some(st) = &settings.global.status {
+        let listen_to = format!("{}:{}", st.address, st.port).to_string();
+        /*
+         * Need to spin this into its own separate thread since tide will blcok 
+         * up the async executor in this thread.
+         */
+        task::spawn(status::status_server(listen_to));
+    }
+
     if let Some(test_file) = matches.value_of("test") {
         return task::block_on(rules::test_rules(&test_file, settings));
     }

src/settings.rs

@@ -164,11 +164,18 @@ pub struct Metrics {
     pub statsd: String,
 }
 
+#[derive(Debug, Deserialize)]
+pub struct Status {
+    pub address: String,
+    pub port: u64,
+}
+
 #[derive(Debug, Deserialize)]
 pub struct Global {
-    pub listen: Listen,
     pub kafka: Kafka,
+    pub listen: Listen,
     pub metrics: Metrics,
+    pub status: Option<Status>,
 }
 
 #[derive(Debug, Deserialize)]

src/status.rs

@@ -0,0 +1,59 @@
+/**
+ * This module contains the necessary code to launch the internal status HTTP
+ * server when so configured by the administrator
+ */
+
+use log::*;
+use tide;
+
+
+/**
+ * Launch the status server
+ */
+pub async fn status_server(listen_to: String) -> Result<(), std::io::Error> {
+    debug!("Starting the status server on: {}", listen_to);
+    let mut app = tide::new();
+    app.at("/").get(|_| async {
+        Ok("Welcome to Hotdog")
+        });
+    app.listen(listen_to).await?;
+    Ok(())
+}
+
+pub struct StatsHandler {
+}
+
+#[derive(Debug, Display)]
+pub enum Stats {
+    #[strum(serialize="connections")]
+    ConnectionCount,
+    #[strum(serialize="lines")]
+    LineReceived,
+    #[strum(serialize="kafka.submitted")]
+    KafkaMsgSubmitted {
+        topic: String,
+    },
+    #[strum(serialize="kafka.producer.sent")]
+    KafkaMsgSent,
+    #[strum(serialize="kafka.producer.error")]
+    KafkaMsgErrored {
+        errcode: String,
+    },
+    LogParseError,
+    FullInternalQueueError,
+    InternalPushError,
+    MergeInvalidJsonError,
+    MergeTargetNotJsonError,
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_sanity_check_strum_serialize() {
+        let s = Stats::ConnectionCount.to_string();
+        assert_eq!("connections", s);
+    }
+}