Add support for Prometheus monitoring

Cargo.toml

@@ -15,6 +15,7 @@ error-chain = "0.11"
 hex = "0.3"
 log = "0.4"
 pbr = "1.0"
+prometheus = "0.4"
 rocksdb = "0.10"
 rust-crypto = "0.2"
 serde = "1.0"
@@ -22,3 +23,4 @@ serde_derive = "1.0"
 serde_json = "1.0"
 simplelog = "0.5"
 time = "0.1"
+tiny_http = "0.6"

src/config.rs

@@ -9,9 +9,10 @@ pub struct Config {
     pub log_file: String,
     pub log_level: simplelog::LevelFilter,
     pub restart: bool,
-    pub network_type: Network, // bitcoind JSONRPC endpoint
+    pub network_type: Network,       // bitcoind JSONRPC endpoint
-    pub db_path: String,       // RocksDB directory path
+    pub db_path: String,             // RocksDB directory path
-    pub rpc_addr: SocketAddr,  // for serving Electrum clients
+    pub rpc_addr: SocketAddr,        // for serving Electrum clients
+    pub monitoring_addr: SocketAddr, // for Prometheus monitoring
 }
 
 impl Config {
@@ -73,6 +74,7 @@ impl Config {
                 Network::Testnet => "127.0.0.1:60001",
             }.parse()
                 .unwrap(),
+            monitoring_addr: "127.0.0.1:42024".parse().unwrap(),
         };
         setup_logging(&config);
         config

src/lib.rs

@@ -8,10 +8,12 @@ extern crate chan_signal;
 extern crate crypto;
 extern crate hex;
 extern crate pbr;
+extern crate prometheus;
 extern crate rocksdb;
 extern crate serde;
 extern crate simplelog;
 extern crate time;
+extern crate tiny_http;
 
 #[macro_use]
 extern crate chan;
@@ -32,6 +34,7 @@ pub mod daemon;
 pub mod errors;
 pub mod index;
 pub mod mempool;
+pub mod metrics;
 pub mod query;
 pub mod rpc;
 pub mod signal;

src/metrics.rs

@@ -0,0 +1,44 @@
+use prometheus::{self, Encoder};
+use std::io;
+use std::net::SocketAddr;
+use tiny_http;
+
+pub use prometheus::{IntCounter as Counter, Opts as MetricOpts};
+
+pub struct Metrics {
+    reg: prometheus::Registry,
+    addr: SocketAddr,
+}
+
+impl Metrics {
+    pub fn new(addr: SocketAddr) -> Metrics {
+        Metrics {
+            reg: prometheus::Registry::new(),
+            addr,
+        }
+    }
+
+    pub fn counter(&self, opts: prometheus::Opts) -> Counter {
+        let cnt = Counter::with_opts(opts).unwrap();
+        self.reg.register(Box::new(cnt.clone())).unwrap();
+        cnt
+    }
+
+    pub fn serve(&self) {
+        let server = tiny_http::Server::http(self.addr).unwrap();
+        loop {
+            if let Err(e) = self.handle(server.recv()) {
+                error!("http error: {}", e);
+            }
+        }
+    }
+    fn handle(&self, req: io::Result<tiny_http::Request>) -> io::Result<()> {
+        let request = req?;
+        let mut buffer = vec![];
+        prometheus::TextEncoder::new()
+            .encode(&self.reg.gather(), &mut buffer)
+            .unwrap();
+        let response = tiny_http::Response::from_data(buffer);
+        request.respond(response)
+    }
+}