main: Implement main program logic

Finally, a working application!  The heavy lifting is handled by
*prometheus_exporter_base*, which sets up the Hyper server and registers
the *GET /metrics* path operation handler.  Really, all we have to
provide is the logic to connect to the BURP stats socket given the
options specified in the configuration file.  The `metrics::get_metrics`
function handles the generation of the metrics, which we return as a
string to be served to the HTTP client.

Cargo.lock

@@ -20,6 +20,35 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "argh"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbb41d85d92dfab96cb95ab023c265c5e4261bb956c0fb49ca06d90c570f1958"
+dependencies = [
+ "argh_derive",
+ "argh_shared",
+]
+
+[[package]]
+name = "argh_derive"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be69f70ef5497dd6ab331a50bd95c6ac6b8f7f17a7967838332743fbd58dc3b5"
+dependencies = [
+ "argh_shared",
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "argh_shared"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6f8c380fa28aa1b36107cd97f0196474bb7241bb95a453c5c01a15ac74b2eac"
+
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -59,6 +88,7 @@ checksum = "a4a45a46ab1f2412e53d3a0ade76ffad2025804294569aae387231a0cd6e0899"
 name = "burp_exporter"
 version = "0.1.0"
 dependencies = [
+ "argh",
  "gethostname",
  "openssl",
  "prometheus_exporter_base",
@@ -66,6 +96,7 @@ dependencies = [
  "serde_json",
  "tokio",
  "tokio-native-tls",
+ "toml",
  "tracing",
  "tracing-subscriber",
 ]
@@ -227,6 +258,15 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "heck"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d621efb26863f0e9924c6ac577e8275e5e6b77455db64ffa6c65c904e9e132c"
+dependencies = [
+ "unicode-segmentation",
+]
+
 [[package]]
 name = "hermit-abi"
 version = "0.1.19"
@@ -941,6 +981,15 @@ dependencies = [
  "webpki",
 ]
 
+[[package]]
+name = "toml"
+version = "0.5.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a31142970826733df8241ef35dc040ef98c679ab14d7c3e54d827099b3acecaa"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "tower-service"
 version = "0.3.1"
@@ -1015,6 +1064,12 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "59547bce71d9c38b83d9c0e92b6066c4253371f15005def0c30d9657f50c7642"
 
+[[package]]
+name = "unicode-segmentation"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7e8820f5d777f6224dc4be3632222971ac30164d4a258d595640799554ebfd99"
+
 [[package]]
 name = "unicode-width"
 version = "0.1.9"

Cargo.toml

@@ -6,10 +6,12 @@ license = "MIT OR Apache-2.0"
 edition = "2021"
 
 [dependencies]
+argh = "^0.1.7"
 openssl = "^0.10.38"
 gethostname = "^0.2.2"
 serde_json = "1.0.78"
 tokio-native-tls = "^0.3.0"
+toml = "^0.5.8"
 tracing = "^0.1.30"
 
 [dependencies.prometheus_exporter_base]

src/main.rs

@@ -1,2 +1,90 @@
-fn main() {
+use std::fs::File;
+use std::io::prelude::*;
+use std::net::IpAddr;
+use std::path::Path;
+
+use argh::FromArgs;
+use prometheus_exporter_base::render_prometheus;
+use toml;
+use tracing::{debug, error};
+
+mod burp;
+mod config;
+mod metrics;
+use burp::client::ClientConnector;
+use config::Config;
+
+/// BURP exporter
+#[derive(FromArgs)]
+struct Args {
+    /// configuration file path
+    #[argh(option, short = 'c')]
+    config_file: Option<String>,
+}
+
+#[tokio::main(flavor = "current_thread")]
+async fn main() {
+    tracing_subscriber::fmt::init();
+    let args: Args = argh::from_env();
+    let config = match load_config(args.config_file) {
+        Ok(c) => c,
+        Err(e) => {
+            eprintln!("Failed to load configuration: {}", e);
+            ::std::process::exit(1);
+        }
+    };
+    let host: IpAddr = match config.listen_host.parse() {
+        Ok(a) => a,
+        Err(e) => {
+            eprintln!("Invalid listen host ({}): {}", &config.listen_host, e);
+            ::std::process::exit(1);
+        }
+    };
+    let addr = (host, config.listen_port).into();
+    debug!("Using configuration: {:?}", &config);
+
+    render_prometheus(addr, config, |_request, config| async move {
+        let mut connector = ClientConnector::new(&config.server);
+        if let Some(server_name) = &config.server_name {
+            connector = connector.server_name(server_name);
+        }
+        if let Some(ca_cert) = &config.ca_cert {
+            connector = connector.ca_cert_file(&ca_cert)?;
+        }
+        if let Some(identity_file) = &config.identity {
+            let password = match &config.identity_password {
+                Some(p) => &p,
+                None => "",
+            };
+            connector = connector.identity_file(identity_file, password)?;
+        }
+        debug!("Connecting to server: {}", &config.server);
+        let mut client = match connector.connect().await {
+            Ok(c) => Ok(c),
+            Err(e) => {
+                error!("Error connecting to server: {}", e);
+                Err(e)
+            }
+        }?;
+        if let Some(p) = &config.password {
+            client.handshake(&config.client_name, Some(p)).await
+        } else {
+            client.handshake(&config.client_name, None).await
+        }?;
+        Ok(metrics::get_metrics(&mut client).await?)
+    })
+    .await;
+}
+
+fn load_config<P: AsRef<Path>>(
+    path: Option<P>,
+) -> Result<Config, Box<dyn std::error::Error>> {
+    if let Some(path) = path {
+        let mut f = File::open(path)?;
+        let mut contents = String::new();
+        f.read_to_string(&mut contents)?;
+        Ok(toml::from_str(&contents)?)
+    } else {
+        Ok(Config::default())
+    }
 }